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Klebsiella pneumoniae colonization in patients with spinal cord injury
DIAGNMICROBILINFECTDIS 1987;7:229-235
229
BACTERIOLOGY
Klebsiella pneumoniae Colonization in Patients with Spinal Cord Injury John Z. Montgomerie, Donna S. Gilmore, Irene E. Graham, Donald G. Schick, Mary A. Ashley, James W. Morrow, and Sandra K. Bruce
Klebsiella pneumoniae colonization of 53 patients with spinal cord injury was studied. Cultures of multiple body sites from patients, the environment, food, and hospital personnel were obtained. K. pneumoniae was cultured from one or more body sites in 46% of male patients. Significant bacteriuria was found in 10% of male patients. Positive cultures of the urethra and perineum for K. pneumoniae were significantly associated with the use of the external condom catheter (p < 0.05, Fisher's exact test). K. pneumoniae colonization increased with length of stay in the hospital. Serotype 64, the predominant serotype found, was isolated only from patients who had been in the hospital for at least 4 wk and primarily in those patients using the external condom catheter. Urinary drainage bags were frequently colonized with K. pneumoniae at a time when the patients did not have significant bacteriuria. Colonized male patients were found to be the primary reservoir of K_. pneumoniae and may serve as the major source for cross-contaminatian.
INTRODUCTION Orskov first described clusters of Klebsiella p n e u m o n i a e infections of the u r i n a r y tract from urological wards. S i m i l a r outbreaks have occurred on other hospital w a r d s and in intensive care units (Casewell et al., 1978; Price et al., 1970; Thomas et al., 1977). Instruments and i n d w e l l i n g urethral catheters have been i m p o r t a n t in the carriage of K. p n e u m o n i a e in these outbreaks. K. p n e u m o n i a e infections of the urinary tract have been an e n d e m i c p r o b l e m on the Spinal Cord Injury Service at our hospital. Patients on this service have urinary tract infectious at some time during their admission, and as m a n y as 50% of the infections have been due to K. p n e u m o n i a e ( u n p u b l i s h e d observations). The present study was carried out to e x a m i n e the prevalence of K. p n e u m o n i a e colonization in these patients and to d e t e r m i n e the reservoirs of K. p n e u m o n i a e on the S p i n a l Injury Service.
From the University of Southern California School of Medicine, Los Angeles and Infectious Disease Division and Division of Urology, Departments of Medicine and Surgery, Rancho Los Amigos Medical Center, Downey, CA 90242. Address reprint requests to: John Z. Montgomerie, M.D., Infectious Disease Division, Rancho Los Amigos Medical Center, 7601 East Imperial Highway, Downey, CA 90242. Received January 31, 1986; accepted April 14, 1987.
Science Publishing Co., Inc. 52 Vanderbilt Avenue, New York, NY 10017
© 1987 Elsevier
0732-8893/87/$3.50
230
J.Z. Montgomerie et al.
MATERIALS AND METHODS Each year approximately 250 patients with spinal cord injury have been admitted to Rancho Los Amigos Medical Center, usually within a few weeks of the injury. Patients admitted to the Spinal Injury Service were managed by intermittent catheterization until spontaneous micturition occurred. At that time an external condom catheter, attached to a drainage bag on the bed or leg-bag, was used on male patients to avoid incontinence. Intermittent catheterization was continued until bladder balance occurred, usually within 4 wk after the injury. Residual urine volume was then measured every 2-4 wk. Urine was obtained by catheter and was sent for culture weekly while the patients were on intermittent catheterization. Later the urine was cultured when the residual urines were measured. Urinary tract infections (bacteriuria I> 108 bacteria/ml) were treated with antibiotics for approximately 5-10 days. Cultures were obtained to examine the prevalence of K. pneumoniae in patients, personnel, and the immediate environment of the two Spinal Injury Units during a 3-day period. Urine cultures obtained by catheter within 1 wk prior to or following the 3-day study period were included in the study. Nineteen patients were not catheterized during the study period. The following sites were cultured: nose, throat, urethra, penis, perineum, anus, and hands. The hands of patients with quadriplegia were not cultured. The hands, nose, and throat of the nursing, occupational, and physical therapy personnel were cultured. The immediate environment such as the patients' linen and bath basins, and the sinks and baths in each unit was cultured. Samples of all hospital food and drink received by the patients for 3 days prior to the study period were also cultured. Methods of Culture Collection Cultures from the skin surface were obtained using sterile swabs (Chesebrough-Ponds, Inc.) moistened in saline. Urethral cultures were obtained by inserting the swab into the meatus. The skin on the perineum was cultured midway between the scrotum and anus. Cultures of the skin of the penis were obtained halfway between the base and the tip of the penis. To obtain anal cultures the swab was inserted approximately 1 cm into the anal canal. A moistened swab was also used to obtain cultures of the anterior nares and a dry swab was used to culture the posterior wall of the pharynx. The sites in the environment were cultured with a moistened swab. Cultures of the hands were obtained by washing the hands in 20 ml of sterile Koser citrate medium (Difco). Methods of Culture All swabs were placed in Koser citrate medium incubated overnight and subcultured onto MacConkey agar (Clinical Standards Laboratories, Carson, CA) and K. pneumonioe isolation agar (Bruce et al., 1981). Urine was cultured in the Clinical Laboratory by standard techniques. Food samples were cut up finely and mixed with 4 ml of Koser citrate medium. After 24 hr the medium was subcultured on to K. pneumoniae isolation agar. All plates were incubated at 36°C for 48 hr. The identification of K. pneumonioe was confirmed by standard techniques. Antimicrobial susceptibility tests were carried out by the Kirby-Bauer technique (Bauer et al., 1966). Serotyping Serotyping was carried out using the counter immunoelectrophoresis (CIE) technique of Palfreyman et al., 1978. Antisera was kindly provided by the Center for Disease Control. The K. pneumoniae isolates were cultured on Worfel-Ferguson agar (BBL)
K. pneumoniae in Spinal Cord Injuries
231
for 18-24 hr at 36°C. Colonies were then subcultured to Mueller-Hinton broth (Difco) and incubated overnight at room temperature. The resulting growth was formalinized and used as antigen in the CIE. The concentration of K. pneumoniae used as antigen was approximately 9 x 108/ml corresponding to a McFarland standard number 3. Agarose plates (0.75) were prepared using tris-barbital-sodium-barbital buffer, pH 8.8. Counter immunoelectrophoresis was carried out using 15 mA/slide for 1 hr. The presence of more than one strain of K. pneumoniae in any site was detected by differences in colony morphology. Only one colony of uniform morphology was serotyped. RESULTS Cultures were obtained from 53 patients (50 men and three women). Twenty-nine of the patients were quadriplegic. Twenty-six patients were only using an external condom catheter and 14 patients were receiving intermittent catheterization. Three of the 14 patients receiving intermittent catheterization were also using an external condom catheter. Four patients had an indwelling urethral catheter at the time of the cultures and nine patients were able to void volitionally. Thirty-seven patients had received antimicrobial agents within 2 wk prior to the study period. Results of the cultures of the urethra, penis, perineum, and anus are shown in Table 1. K. pneumoniae was not isolated from any site of the three women and therefore are not shown in the table. The urethra, penis, perineum, and anus were colonized with K. pneumoniae in 28%, 32%, 34%, and 36% of male patients, respectively. K. pneumoniae was isolated from one or more sites in 46% of male patients. Significant bacteriuria with K. pneumoniae (/>10 s bacteria/ml) was found in three of 31 (10%) male patients and was associated with a positive culture at one or more body sites in all three cases. Positive urethral and perineal cultures were significantly associated with the use of the external condom catheter (p < 0.05 by Fisher's exact test; Table 2). Antibiotics active against K. pneumoniae, being used at the time of the culture or within 2 wk prior to the culture, reduced colonization of the urethra, penis, perineum, or anus; however, antibiotic use in general had no effect on colonization. Colonization of all sites increased with duration of hospital stay (Table 3). Although this partially reflects the increased use of the external condom catheter, which usually began 4-8 wk after admission to hospital, a separate effect of duration of hospital stay on colonization could be observed. Colonization with K. pneumoniae in Male Patients a w i t h Spinal Cord Injury
TABLE 1.
Body site Urethra Penis Perineum Anus Urine Urethra, penis, perineum, or anus Hands Nose Throat
Total patients
Number of patients (%) 14/50 16/50 17/50 18/50 3/31 23/50 4/22 1/50 2/50
(28) (32) (34) (36) (10) (46) (18) (2) (4)
50
°No Klebsiella was isolated from the three female patients who, therefore, not included in the table.
J.Z. Montgomerie et al.
232
TABLE 2. Colonization of Men with K. pneumoniae Positive Culture (%) Urethra
Penis
Perineum
Anus
13/29a (44) 4/21a (19)
11/29 (38) 7/21 (33)
3/12 (25) 14/38 (37)
4/12 (33) 14/38 (37)
11/28 (39) 6/22 (27)
11/28 (39) 7/22 (32)
13/35 (37) 4/15 (27)
12/35 (34) 6/15 (40)
EXTERNAL CATHETER
Yes No
12/29" (41) 2/21" (10)
Yes No
2/12 (17) 12/38 (32)
Yes No
10/28 (36) 4/22 (18)
Yes No
10/35 (29) 4/15 (27)
12/29 (41) 4/21 (19) INTERMITTENT CATHETERIZATION
3/12 (25) 13/38 (34) QUADRIPLEGIA
11/28 (39) 5/22 (23) ANTIBIOTICS
Yes
0/5
11/35 (31) 5/15 (33) ANTI-K/ZBSIELLAANTIBIOTICSb 0/5
1/5
(20)
0/5
Qp< 0.05 (Fisher'sexact text). bAminoglycosidesand cephalosporins.
K. pneumoniae was cultured from eight of 33 (24%) drainage bags on the patients' beds and five of 23 (22%) drainage bags on the legs of the patients. The presence of K. pneumoniae in the u r i n a r y drainage bag on the bed or leg-bag was closely associated with colonization of the urethra, penile shaft, and p e r i n e u m in seven of eight patients with positive drainage bags. Cultures of the anus were positive in four of eight patients in w h o m the drainage bag was positive. K. p n e u m o n i a e was cultured from one patient's drainage bag w h e n the body sites were found not to be colonized. Twenty-two percent (four of 18) of the sinks examined had K. pneumoniae and 12% (six of 49) of the bed l i n e n s on the patients' beds was positive for K. p n e u m o n i a e . K. p n e u m o n i a e was cultured from one of three bathtubs. K. p n e u m o n i a e was found in three of 49 (6%) samples of food. The positive samples were lettuce, orange juice, and a breakfast roll. The hands of five of 74 (7%) and the nose or throat of four of 74 (5%) hospital staff were positive for K. pneumoniae. Serotyping was carried out on 74 K. p n e u m o n i a e isolates from body sites of patients and 34 isolates from other sources. Type 64, the most frequent K. pneumoniae serotype cultured, comprised 24 of 74 (33%) strains isolated from body sites and was
TABLE 3. Klebsiella Colonization in Men in Relation to Duration of Hospital Stay Body site Urethra Penis Perineum Anus
<3 wk (%) 1/8 1/8 1/8 2/8
(12) (13) (13) (25)
4-8 wk (%) 3/15 4/15 6/15 5/15
(20) (27) (40) (33)
>8 wk (%) 7/20 (35) 7/20 (35) 7/20 (35) 7/20 (35)
Readmitted ° (%) 3/7 4/7 3/7 4/7
(43) (57) (43) (57)
aThese male patients readmitted to hospital were not included in other groups (<3 wk, 4 4 wk, and >8 wk).
K. pneumoniae in Spinal Cord Injuries
233
found only on patients after 4 wk of hospitalization and ten of 11 patients with serotype 64 were using the external catheter. Eleven of 74 strains (15%) were nontypable and ten strains (13%) were type 7. The serotypes cultured from patients were frequently different in different positive body sites in each patient. In patients with two or more positive sites, the same serotype was isolated from all sites in only seven of 18 patients. There were some differences in serotypes isolated from patients in the two wards. Type 7 was cultured from four patients and one nurse, all from one ward. Serotypes from the drainage bags were the same as the serotypes found on the patients in five of seven instances. Strains of K. pneumoniae from the environment were essentially those found on the patients. Serotypes found on the linen were cultured from the patients occupying the bed in five of six instances. No visible signs of fecal contamination were found when the linen was cultured. Two of the three serotypes cultured from the food were not found elsewhere. All the serotypes found on the personnel were also found colonizing patients. K. pneumoniae was cultured on the hands of four of 22 (18%) patients studied. Two of the four positive cultures were from patients without other body colonization. Antimicrobial susceptibility tests were carried out on the perineal isolates. Six of eight strains of serotype 64 were resistant to gentamicin and tobramycin. Aminoglycoside resistance was only seen in serotype 84. DISCUSSION In the present study of patients with spinal cord injury there was a high prevalence of K. pneumoniae on the perineum and urethra, which was associated with the use of the external condom catheter. Bacteriuria with K. pneumoniae, seen in three patients, was associated with other colonized body sites. These men used an external condom catheter with leg drainage because of risks of incontinence. Colonized urethras, perinea, penile skin, and urinary drainage bags may be potential reservoirs of K. pneumoniae in these patients. Colonization of drainage bags of the patients with bacteriuria and indwelling catheter is well known; however, in the present study, patients without indwelling catheters or significant bacteriuria frequently had K. pneumoniae in the drainage bags. The detection of K. pneumoniae in the urine of these drainage bags was a sensitive indicator of colonization of other body sites. Anal colonization was not associated with the use of the external condom catheter and other factors may influence bowel colonization. Although acquisition of K. pneumoniae in the stool has been linked to antibiotic use in earlier studies of other groups of patients (Montgomerie, 1979) we did not correlate antibiotic therapy with K. pneumonioe colonization. In another study we had shown that the bowel was the likely source of K. pneumoniae on the perineum of spinal cord injured patients (Gilmore et al., 1982). In the present study using serotyping, there was some evidence that the perineum may develop its own flora of K. pneumoniae separate from the faecal flora, because different serotypes were found in the perineal and anal cultures in four of 11 cases. This interpretation may be difficult because it is possible that more than one serotype of Klebsiella may be present at any site. Because it is not possible to serotype large numbers of colonies with the same morphology from each site it is difficult to rule out the possibility that there is more than one serotype present. Serotype 64, which was resistant to gentamicin and tobramycin, appeared to be acquired in hospital, and was less frequently seen in the anal culture. This serotype was closely associated with use of the external condom catheter, which usually began after some weeks in hospital.
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J.Z. Montgomerie et al.
K. pneumoniae on linen reflected body colonization. Five of six strains were the same as these found on the patients. In the hospital environment K. pneumoniae was also found in the sinks, baths, and other moist areas from which they could be transferred to patients. Serotyping of the K. pneumoniae indicated that a large variety of serotypes were isolated from various sources although there was clustering of serotype 7 involving four patients on one unit. The isolation of serotype 64 from patients only after 4 wk in the hospital and the resistance of this strain to aminoglycosides also indicated that this was a hospital strain. K. pneumoniae with serotypes the same as those found on the patients were found in 7% of the hands of hospital staff. This supports previous studies that suggest that the hands may be an important means of transmission of K. pneumoniae (Montgomerie, 1979). Some support for this might be that the prevalence of K. pneumoniae type 64 was higher in the quadriplegics (five of 12) than in the paraplegics (zero of five) after 8 wk of hospitalization in patients using the external c o n d o m catheter. The quadriplegics, who are unable to replace their own external c o n d o m catheters, receive more direct, hands-on care from personnel than the paraplegics who are trained to replace their own. Two patients also had K. pneumoniae on their hands at a time when other body sites were negative. The source of these strains was not clear. Food was not a significant source of K. pneumoniae in the present study. The number of w o m e n examined was too small to make comparisons, but no K. pneumoniae was cultured from the three w o m e n studied. In another study we observed perineal colonization with K. pneumoniae in five of 11 w o m e n (unpublished observation). In previous studies we have shown a high prevalence of Pseudomonas aeruginosa colonization in patients with spinal cord injury (Montgomerie et al., 1978). There seem to be some significant differences between P. aeruginoso colonization and the colonization with K. pneumoniae found in this study. K. pneumoniae was most frequently found in the anal and perineal cultures. P. aeruginosa was found more frequently on the perineal and urethral cultures. Culturing the perineum, however, was a sensitive indicator of colonization with K. pneumoniae or P. aeruginosa in these patients. A c o m m o n finding was the association between colonization and use of the external c o n d o m catheter. It is unclear w h y the use of the external c o n d o m catheter is associated with the presence of K. pneumoniae and P. aeruginosa. Moisture has been thought to be an important factor in colonization of the skin with P. aeruginosa and may be an important link to the colonization of these patients (Marples, 1965). However, we were unable to show an association of moisture with the presence of Klebsiella or Pseudomonas on the skin of the perineum (Montgomerie et al., 1983). Longitudinal studies will be necessary to determine if the presence of the K. pneumoniae on the skin reflects contamination from other sites or if, indeed, the K. pneumoniae has colonized the perineal skin. Patients with spinal cord injury have special problems with K. pneumoniae colonization. In previous studies we have shown that Klebsiella and Pseudomonas persist on the skin despite meticulous bathing or use of antiseptics (Gilmore et el., 1981; Gilmore et el., 1984). It is important to develop methods that may reduce colonization and the risk of infection in this group.
Supported in part by the Weingart Foundation in this study. The authors acknowledge the technical assistance of Gloria Aeilts, R.N., Barbara AUdis, R.N., and Enes Jimenez, R.N., and Jean Lloyd for her help with the preparation of the manuscript.
K. p n e u m o n i a e i n Spinal Cord Injuries
235
REFERENCES Bauer AW, Kirby WM, Sherris JC et al (1966} Antibiotic susceptibility testing by a standardized single disk method. Am ] Clin Pothol 45:493. Bruce SK, Schick DG, Tanaka L, et al (1981) A selective medium for isolation of Klebsiella pneumoniae. ] Clin Microbiol 13:115. Casewell MW, Phillips I (1978) Epidemiological patterns of klebsiella colonization and infection in an intensive care ward. ] Hyg (Cambridge}00:295. Gilmore DS, Jimenez, EM, Aeilts GD, Alldis BA, Bruce SK, Schick DG, Morrow JW, Montgomerie JZ (1981) Effects of bathing on colonization of spinal cord injury patients with Pseudomonas and Klebsiella. ] C/in Microbiol 14:404-407. Gilmore DS, Schick DG, Montgomerie JZ (1982) Pseudomonas aeruginosa and Klebsiella pneumoniae on the perinea of males with spinal cord injuries. J C/in Microbio 16:865. Gilmore DS, Montgomerie JZ, Graham IE, Schick DG, Jimenez EM {1984) Effect of antiseptic agents on skin flora of the perineum of men with spinal cord injury. Infect Con 5:431--434. Marples RR (1965) The effect of hydration on the bacterial flora of the skin. In Skin Bacteria and Their Role in Infection. Eds., HI Maibach, G. Hildick-Smith. New York: McGraw-Hill, pp. 33-41. Montgomerie JZ, Morrow JW (1978) Pseudomonas colonization in patients with spinal cord injury. Am ] Epidemiol 108:328. Montgomerie JZ (1979) Epidemiology of Klebsiella and hospital-associated infections. Ray Infec Dis 1:736. Montgomerie JZ, Schick DG, Gilmore DS, Graham IE {1983} pH and water content of Pseudomonas aeruginosa- and Klebsiel|a pneumoniae- colonized perineal skin of men with spinal cord injuries. ] Clin Microbiol 18:844-848. 0rskov I (1952) Nosocomial infections with KlebsieHa in lesions of the urinary tract. Acta Pathol Microbiol Scand {suppl.)93:259. Palfreyman JM (1978) Klebsiella serotyping by counter-current immunoelectrophoresis. ] Hyg (Cambridge)81:219. Price DJE, Sleigh JD (1970) Control of infection due to Klebsiella aerogenes in a neurosurgical unit by withdrawal of all antibiotics. Lancet ii:1213. Thomas FE, Jackson RT, Melly MD et al (1977) Sequential hospitalwide outbreaks of resistant serratia and klebsiella infections. Arch Intern Med 137:581.
229
BACTERIOLOGY
Klebsiella pneumoniae Colonization in Patients with Spinal Cord Injury John Z. Montgomerie, Donna S. Gilmore, Irene E. Graham, Donald G. Schick, Mary A. Ashley, James W. Morrow, and Sandra K. Bruce
Klebsiella pneumoniae colonization of 53 patients with spinal cord injury was studied. Cultures of multiple body sites from patients, the environment, food, and hospital personnel were obtained. K. pneumoniae was cultured from one or more body sites in 46% of male patients. Significant bacteriuria was found in 10% of male patients. Positive cultures of the urethra and perineum for K. pneumoniae were significantly associated with the use of the external condom catheter (p < 0.05, Fisher's exact test). K. pneumoniae colonization increased with length of stay in the hospital. Serotype 64, the predominant serotype found, was isolated only from patients who had been in the hospital for at least 4 wk and primarily in those patients using the external condom catheter. Urinary drainage bags were frequently colonized with K. pneumoniae at a time when the patients did not have significant bacteriuria. Colonized male patients were found to be the primary reservoir of K_. pneumoniae and may serve as the major source for cross-contaminatian.
INTRODUCTION Orskov first described clusters of Klebsiella p n e u m o n i a e infections of the u r i n a r y tract from urological wards. S i m i l a r outbreaks have occurred on other hospital w a r d s and in intensive care units (Casewell et al., 1978; Price et al., 1970; Thomas et al., 1977). Instruments and i n d w e l l i n g urethral catheters have been i m p o r t a n t in the carriage of K. p n e u m o n i a e in these outbreaks. K. p n e u m o n i a e infections of the urinary tract have been an e n d e m i c p r o b l e m on the Spinal Cord Injury Service at our hospital. Patients on this service have urinary tract infectious at some time during their admission, and as m a n y as 50% of the infections have been due to K. p n e u m o n i a e ( u n p u b l i s h e d observations). The present study was carried out to e x a m i n e the prevalence of K. p n e u m o n i a e colonization in these patients and to d e t e r m i n e the reservoirs of K. p n e u m o n i a e on the S p i n a l Injury Service.
From the University of Southern California School of Medicine, Los Angeles and Infectious Disease Division and Division of Urology, Departments of Medicine and Surgery, Rancho Los Amigos Medical Center, Downey, CA 90242. Address reprint requests to: John Z. Montgomerie, M.D., Infectious Disease Division, Rancho Los Amigos Medical Center, 7601 East Imperial Highway, Downey, CA 90242. Received January 31, 1986; accepted April 14, 1987.
Science Publishing Co., Inc. 52 Vanderbilt Avenue, New York, NY 10017
© 1987 Elsevier
0732-8893/87/$3.50
230
J.Z. Montgomerie et al.
MATERIALS AND METHODS Each year approximately 250 patients with spinal cord injury have been admitted to Rancho Los Amigos Medical Center, usually within a few weeks of the injury. Patients admitted to the Spinal Injury Service were managed by intermittent catheterization until spontaneous micturition occurred. At that time an external condom catheter, attached to a drainage bag on the bed or leg-bag, was used on male patients to avoid incontinence. Intermittent catheterization was continued until bladder balance occurred, usually within 4 wk after the injury. Residual urine volume was then measured every 2-4 wk. Urine was obtained by catheter and was sent for culture weekly while the patients were on intermittent catheterization. Later the urine was cultured when the residual urines were measured. Urinary tract infections (bacteriuria I> 108 bacteria/ml) were treated with antibiotics for approximately 5-10 days. Cultures were obtained to examine the prevalence of K. pneumoniae in patients, personnel, and the immediate environment of the two Spinal Injury Units during a 3-day period. Urine cultures obtained by catheter within 1 wk prior to or following the 3-day study period were included in the study. Nineteen patients were not catheterized during the study period. The following sites were cultured: nose, throat, urethra, penis, perineum, anus, and hands. The hands of patients with quadriplegia were not cultured. The hands, nose, and throat of the nursing, occupational, and physical therapy personnel were cultured. The immediate environment such as the patients' linen and bath basins, and the sinks and baths in each unit was cultured. Samples of all hospital food and drink received by the patients for 3 days prior to the study period were also cultured. Methods of Culture Collection Cultures from the skin surface were obtained using sterile swabs (Chesebrough-Ponds, Inc.) moistened in saline. Urethral cultures were obtained by inserting the swab into the meatus. The skin on the perineum was cultured midway between the scrotum and anus. Cultures of the skin of the penis were obtained halfway between the base and the tip of the penis. To obtain anal cultures the swab was inserted approximately 1 cm into the anal canal. A moistened swab was also used to obtain cultures of the anterior nares and a dry swab was used to culture the posterior wall of the pharynx. The sites in the environment were cultured with a moistened swab. Cultures of the hands were obtained by washing the hands in 20 ml of sterile Koser citrate medium (Difco). Methods of Culture All swabs were placed in Koser citrate medium incubated overnight and subcultured onto MacConkey agar (Clinical Standards Laboratories, Carson, CA) and K. pneumonioe isolation agar (Bruce et al., 1981). Urine was cultured in the Clinical Laboratory by standard techniques. Food samples were cut up finely and mixed with 4 ml of Koser citrate medium. After 24 hr the medium was subcultured on to K. pneumoniae isolation agar. All plates were incubated at 36°C for 48 hr. The identification of K. pneumonioe was confirmed by standard techniques. Antimicrobial susceptibility tests were carried out by the Kirby-Bauer technique (Bauer et al., 1966). Serotyping Serotyping was carried out using the counter immunoelectrophoresis (CIE) technique of Palfreyman et al., 1978. Antisera was kindly provided by the Center for Disease Control. The K. pneumoniae isolates were cultured on Worfel-Ferguson agar (BBL)
K. pneumoniae in Spinal Cord Injuries
231
for 18-24 hr at 36°C. Colonies were then subcultured to Mueller-Hinton broth (Difco) and incubated overnight at room temperature. The resulting growth was formalinized and used as antigen in the CIE. The concentration of K. pneumoniae used as antigen was approximately 9 x 108/ml corresponding to a McFarland standard number 3. Agarose plates (0.75) were prepared using tris-barbital-sodium-barbital buffer, pH 8.8. Counter immunoelectrophoresis was carried out using 15 mA/slide for 1 hr. The presence of more than one strain of K. pneumoniae in any site was detected by differences in colony morphology. Only one colony of uniform morphology was serotyped. RESULTS Cultures were obtained from 53 patients (50 men and three women). Twenty-nine of the patients were quadriplegic. Twenty-six patients were only using an external condom catheter and 14 patients were receiving intermittent catheterization. Three of the 14 patients receiving intermittent catheterization were also using an external condom catheter. Four patients had an indwelling urethral catheter at the time of the cultures and nine patients were able to void volitionally. Thirty-seven patients had received antimicrobial agents within 2 wk prior to the study period. Results of the cultures of the urethra, penis, perineum, and anus are shown in Table 1. K. pneumoniae was not isolated from any site of the three women and therefore are not shown in the table. The urethra, penis, perineum, and anus were colonized with K. pneumoniae in 28%, 32%, 34%, and 36% of male patients, respectively. K. pneumoniae was isolated from one or more sites in 46% of male patients. Significant bacteriuria with K. pneumoniae (/>10 s bacteria/ml) was found in three of 31 (10%) male patients and was associated with a positive culture at one or more body sites in all three cases. Positive urethral and perineal cultures were significantly associated with the use of the external condom catheter (p < 0.05 by Fisher's exact test; Table 2). Antibiotics active against K. pneumoniae, being used at the time of the culture or within 2 wk prior to the culture, reduced colonization of the urethra, penis, perineum, or anus; however, antibiotic use in general had no effect on colonization. Colonization of all sites increased with duration of hospital stay (Table 3). Although this partially reflects the increased use of the external condom catheter, which usually began 4-8 wk after admission to hospital, a separate effect of duration of hospital stay on colonization could be observed. Colonization with K. pneumoniae in Male Patients a w i t h Spinal Cord Injury
TABLE 1.
Body site Urethra Penis Perineum Anus Urine Urethra, penis, perineum, or anus Hands Nose Throat
Total patients
Number of patients (%) 14/50 16/50 17/50 18/50 3/31 23/50 4/22 1/50 2/50
(28) (32) (34) (36) (10) (46) (18) (2) (4)
50
°No Klebsiella was isolated from the three female patients who, therefore, not included in the table.
J.Z. Montgomerie et al.
232
TABLE 2. Colonization of Men with K. pneumoniae Positive Culture (%) Urethra
Penis
Perineum
Anus
13/29a (44) 4/21a (19)
11/29 (38) 7/21 (33)
3/12 (25) 14/38 (37)
4/12 (33) 14/38 (37)
11/28 (39) 6/22 (27)
11/28 (39) 7/22 (32)
13/35 (37) 4/15 (27)
12/35 (34) 6/15 (40)
EXTERNAL CATHETER
Yes No
12/29" (41) 2/21" (10)
Yes No
2/12 (17) 12/38 (32)
Yes No
10/28 (36) 4/22 (18)
Yes No
10/35 (29) 4/15 (27)
12/29 (41) 4/21 (19) INTERMITTENT CATHETERIZATION
3/12 (25) 13/38 (34) QUADRIPLEGIA
11/28 (39) 5/22 (23) ANTIBIOTICS
Yes
0/5
11/35 (31) 5/15 (33) ANTI-K/ZBSIELLAANTIBIOTICSb 0/5
1/5
(20)
0/5
Qp< 0.05 (Fisher'sexact text). bAminoglycosidesand cephalosporins.
K. pneumoniae was cultured from eight of 33 (24%) drainage bags on the patients' beds and five of 23 (22%) drainage bags on the legs of the patients. The presence of K. pneumoniae in the u r i n a r y drainage bag on the bed or leg-bag was closely associated with colonization of the urethra, penile shaft, and p e r i n e u m in seven of eight patients with positive drainage bags. Cultures of the anus were positive in four of eight patients in w h o m the drainage bag was positive. K. p n e u m o n i a e was cultured from one patient's drainage bag w h e n the body sites were found not to be colonized. Twenty-two percent (four of 18) of the sinks examined had K. pneumoniae and 12% (six of 49) of the bed l i n e n s on the patients' beds was positive for K. p n e u m o n i a e . K. p n e u m o n i a e was cultured from one of three bathtubs. K. p n e u m o n i a e was found in three of 49 (6%) samples of food. The positive samples were lettuce, orange juice, and a breakfast roll. The hands of five of 74 (7%) and the nose or throat of four of 74 (5%) hospital staff were positive for K. pneumoniae. Serotyping was carried out on 74 K. p n e u m o n i a e isolates from body sites of patients and 34 isolates from other sources. Type 64, the most frequent K. pneumoniae serotype cultured, comprised 24 of 74 (33%) strains isolated from body sites and was
TABLE 3. Klebsiella Colonization in Men in Relation to Duration of Hospital Stay Body site Urethra Penis Perineum Anus
<3 wk (%) 1/8 1/8 1/8 2/8
(12) (13) (13) (25)
4-8 wk (%) 3/15 4/15 6/15 5/15
(20) (27) (40) (33)
>8 wk (%) 7/20 (35) 7/20 (35) 7/20 (35) 7/20 (35)
Readmitted ° (%) 3/7 4/7 3/7 4/7
(43) (57) (43) (57)
aThese male patients readmitted to hospital were not included in other groups (<3 wk, 4 4 wk, and >8 wk).
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found only on patients after 4 wk of hospitalization and ten of 11 patients with serotype 64 were using the external catheter. Eleven of 74 strains (15%) were nontypable and ten strains (13%) were type 7. The serotypes cultured from patients were frequently different in different positive body sites in each patient. In patients with two or more positive sites, the same serotype was isolated from all sites in only seven of 18 patients. There were some differences in serotypes isolated from patients in the two wards. Type 7 was cultured from four patients and one nurse, all from one ward. Serotypes from the drainage bags were the same as the serotypes found on the patients in five of seven instances. Strains of K. pneumoniae from the environment were essentially those found on the patients. Serotypes found on the linen were cultured from the patients occupying the bed in five of six instances. No visible signs of fecal contamination were found when the linen was cultured. Two of the three serotypes cultured from the food were not found elsewhere. All the serotypes found on the personnel were also found colonizing patients. K. pneumoniae was cultured on the hands of four of 22 (18%) patients studied. Two of the four positive cultures were from patients without other body colonization. Antimicrobial susceptibility tests were carried out on the perineal isolates. Six of eight strains of serotype 64 were resistant to gentamicin and tobramycin. Aminoglycoside resistance was only seen in serotype 84. DISCUSSION In the present study of patients with spinal cord injury there was a high prevalence of K. pneumoniae on the perineum and urethra, which was associated with the use of the external condom catheter. Bacteriuria with K. pneumoniae, seen in three patients, was associated with other colonized body sites. These men used an external condom catheter with leg drainage because of risks of incontinence. Colonized urethras, perinea, penile skin, and urinary drainage bags may be potential reservoirs of K. pneumoniae in these patients. Colonization of drainage bags of the patients with bacteriuria and indwelling catheter is well known; however, in the present study, patients without indwelling catheters or significant bacteriuria frequently had K. pneumoniae in the drainage bags. The detection of K. pneumoniae in the urine of these drainage bags was a sensitive indicator of colonization of other body sites. Anal colonization was not associated with the use of the external condom catheter and other factors may influence bowel colonization. Although acquisition of K. pneumoniae in the stool has been linked to antibiotic use in earlier studies of other groups of patients (Montgomerie, 1979) we did not correlate antibiotic therapy with K. pneumonioe colonization. In another study we had shown that the bowel was the likely source of K. pneumoniae on the perineum of spinal cord injured patients (Gilmore et al., 1982). In the present study using serotyping, there was some evidence that the perineum may develop its own flora of K. pneumoniae separate from the faecal flora, because different serotypes were found in the perineal and anal cultures in four of 11 cases. This interpretation may be difficult because it is possible that more than one serotype of Klebsiella may be present at any site. Because it is not possible to serotype large numbers of colonies with the same morphology from each site it is difficult to rule out the possibility that there is more than one serotype present. Serotype 64, which was resistant to gentamicin and tobramycin, appeared to be acquired in hospital, and was less frequently seen in the anal culture. This serotype was closely associated with use of the external condom catheter, which usually began after some weeks in hospital.
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K. pneumoniae on linen reflected body colonization. Five of six strains were the same as these found on the patients. In the hospital environment K. pneumoniae was also found in the sinks, baths, and other moist areas from which they could be transferred to patients. Serotyping of the K. pneumoniae indicated that a large variety of serotypes were isolated from various sources although there was clustering of serotype 7 involving four patients on one unit. The isolation of serotype 64 from patients only after 4 wk in the hospital and the resistance of this strain to aminoglycosides also indicated that this was a hospital strain. K. pneumoniae with serotypes the same as those found on the patients were found in 7% of the hands of hospital staff. This supports previous studies that suggest that the hands may be an important means of transmission of K. pneumoniae (Montgomerie, 1979). Some support for this might be that the prevalence of K. pneumoniae type 64 was higher in the quadriplegics (five of 12) than in the paraplegics (zero of five) after 8 wk of hospitalization in patients using the external c o n d o m catheter. The quadriplegics, who are unable to replace their own external c o n d o m catheters, receive more direct, hands-on care from personnel than the paraplegics who are trained to replace their own. Two patients also had K. pneumoniae on their hands at a time when other body sites were negative. The source of these strains was not clear. Food was not a significant source of K. pneumoniae in the present study. The number of w o m e n examined was too small to make comparisons, but no K. pneumoniae was cultured from the three w o m e n studied. In another study we observed perineal colonization with K. pneumoniae in five of 11 w o m e n (unpublished observation). In previous studies we have shown a high prevalence of Pseudomonas aeruginosa colonization in patients with spinal cord injury (Montgomerie et al., 1978). There seem to be some significant differences between P. aeruginoso colonization and the colonization with K. pneumoniae found in this study. K. pneumoniae was most frequently found in the anal and perineal cultures. P. aeruginosa was found more frequently on the perineal and urethral cultures. Culturing the perineum, however, was a sensitive indicator of colonization with K. pneumoniae or P. aeruginosa in these patients. A c o m m o n finding was the association between colonization and use of the external c o n d o m catheter. It is unclear w h y the use of the external c o n d o m catheter is associated with the presence of K. pneumoniae and P. aeruginosa. Moisture has been thought to be an important factor in colonization of the skin with P. aeruginosa and may be an important link to the colonization of these patients (Marples, 1965). However, we were unable to show an association of moisture with the presence of Klebsiella or Pseudomonas on the skin of the perineum (Montgomerie et al., 1983). Longitudinal studies will be necessary to determine if the presence of the K. pneumoniae on the skin reflects contamination from other sites or if, indeed, the K. pneumoniae has colonized the perineal skin. Patients with spinal cord injury have special problems with K. pneumoniae colonization. In previous studies we have shown that Klebsiella and Pseudomonas persist on the skin despite meticulous bathing or use of antiseptics (Gilmore et el., 1981; Gilmore et el., 1984). It is important to develop methods that may reduce colonization and the risk of infection in this group.
Supported in part by the Weingart Foundation in this study. The authors acknowledge the technical assistance of Gloria Aeilts, R.N., Barbara AUdis, R.N., and Enes Jimenez, R.N., and Jean Lloyd for her help with the preparation of the manuscript.
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