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Contamination of the environment of spinal cord injured patients by organisms causing urinary-tract infection
Journal
of Hospital
Infection
Contamination injured patients
Philip Royal
National
(1987)
10, 173-178
of the environment of spinal cord by organisms causing urinary-tract infection J. Sanderson
Orthopaedic
and Pratima
Hospital,
Brockley
Accepted for publication
Rawal
Hill,
14 November
Stanmore
HA7 4LP
1986
Summary: Various environmental sites closely associated with spinallymjured patients were examined for contamination by organisms concurrently causing urinary infection. Of 30 episodes studied, the same organism was recovered from bedding on 20 occasions, from nine of 20 bath towels and less frequently from face cloths, clothing, wheelchairs and bedside units. The results indicate that contact with the immediate environment of spinal patients with urinary infection may lead to contamination of hands, and confirm and expand the need for handwashing by patients and staff.
Introduction Spinally-injured patients undergoing bladder care by indwelling or intermittent catheterization and condom drainage are susceptible to urinary infection and subject to episodes of cross-infection. Organisms are transferred between patients via the hands of staff in contact with urine or drainage apparatus. However, the skin of the perinea and groins of spinally-injured patients has been shown to be frequently and stably colonized with Gram-negative bacilli (Montgomerie & Morrow, 1980; Gilmore, Schick & Montgomerie, 1981). The organisms found were those often associated with hospital-acquired infection of the urinary tract. Fawcett et al. (1986) did not find such organisms at these sites in healthy, ambulant, control subjects. It is possible that environmental contamination of bedding, clothing, seats and towels may result from infected urine and/or perineal colonization. We have investigated various environmental sites of spinal cord injured patients for contamination with organisms causing urinary-tract infection. Patients, Patients Thirty episodes 0195%6701/87/0501i3+06
materials
of urinary-tract
and methods
infection
803 00,O
173
were
investigated
between
2
174
P. J. Sanderson
and P. Rawal
November 198.5 and 21 March 1986 in 17 patients admitted to the Spinal Injuries Unit, Royal National Orthopaedic Hospital, Stanmore. Each patient was undergoing sterile, intermittent bladder catheterization and most wore a penile condom and a urine drainage bag between catheterizations. The patients spent a large part of each day in wheelchairs and received rehabilitation in a separate unit. Urinary infection Urinary-tract infection was diagnosed by using “Dip Slides” (Oxoid Ltd., Basingstoke) which were taken daily in the ward from each patient and examined in the Microbiology Laboratory. Urinary-tract infection was defined as two consecutive counts of > lo5 cfu ml-‘. Positive cultures were sub-cultured on to CLED agar and identified by the -4PI20E system; antibiotic sensitivities were read by the comparative disc method on DST agar (Oxoid Ltd.). Patients received appropriate antibacterial treatment within 24 h of receipt of a positive report. Of the 17 patients studied, 11 had one urinary infection, two had two, one had three and three patients had four infections. In three patients two urinary infections occurred with the same organism, in two of whom there was an interval of at least one month between episodes. In the third patient there were 12 days between infections. All other urinary infections were with different organisms. Environmental sampling Sweep plates were composed of plastic Petri dishes containing cysteine lactose electrolyte deficient (CLED) agar (Lab M, Salford). The surfaces of the pillows and the over and under sheets of each patient’s bedding were individually sampled by sweep plates held so that the edges of the plate lightly scraped the linen surfaces. Patients’ bath towels, face cloths, clothing and wheelchair seats were sampled in the same way. The surfaces and edges of bedside tables and wheelchair arm rests were sampled by rubbing with cotton-tipped swabs, premoistened in transport medium. These were inoculated on to CLED medium within 1 h of sampling. Samples were obtained within 1 or 2 days after diagnosis of urinary infection, sometimes after the start of antibiotic therapy. Bacteriology Sweep plates and inoculated CLED agar plates were incubated at 37°C overnight in air. Colonies resembling those of the organisms recovered from the previous positive urine sample of the patient were sub-cultured on to DST agar for comparison of antibiotic sensitivities by the disc method. Strains with antibiograms identical to that of the urinary isolate were tested in the API20E system and, if the same profile was found, the strain was sent to Reference Laboratories for serotyping or bacteriocin typing. The identity of Proteus strains was tested by the Dienes’ phenomenon (Dienes, 1946).
Environmental
contamination
175
in UT1
Of the 30 organisms isolated from the 30 episodes of urinary infection, 26 were characterized by antibiogram, API profile and serotype or bacteriocin type. Two strains of Proteus mirabilis were characterized by antibiogram, API profile and the Dienes’ phenomenon and one strain of Klebsiella ozaenae by antibiogram and API profile only. One strain of Enterobacter died before exammation could be completed. The corresponding environmental strains (if any) were characterized by the same methods and regarded as identical to the corresponding urinary isolate when antibiogram, API profile, serotype, Dienes’ result or bacteriocin type were the same as in the patient’s urinary isolate. Results
In 20 of the 30 episodes of urinary-tract infection studied an identical organism to that causing the patient’s urinary infection was recovered from the bedding of the patient. Bath towels belonging to patients were examined during episodes of urinary infection on 20 occasions and on nine yielded the patient’s urinary organism. Face cloths, clothing, bedside tables and wheelchairs were sampled less often but all yielded the urinary organism on occasion, albeit with less frequency than in the case of bedding or bath towels (Table I). Table
I. Number
of occasions organisms
causing urinary sites
No. of occasions
recovered
No. of episodes of urinary infection (no. of patients)
Patients’ bedding
Bath towel
Face cloth
Clothing
30(17)
20(30)
9(20)
3(10)
3(13)
infection
recoaeredfrom
(no. of examinations)
encironmental from
Bedside table
Seat
Wheelchair arms & reams
2(17)
3(10)
1(10)
Klebsiella pneumoniae was isolated from nine episodes of urinary-tract infection (Table II). Of the 14 sweep plate samplings obtained from patients’ bedding and bath towels during these nine episodes, 11 yielded an identical strain of K. pneumoniae to that found in the patient’s urinary tract. The same strain of Escherichia coli as in the urine was recovered from five of nine samplings of patient’s bedding and bath towels. Similar recovery rates were obtained for Enterobacter cloacae (five of 12 samplings), Serratia marcescens (six of six), Acinetobacter calcoaceticus var. anitratus (two of two) and K. ozaenae (one of two). The extent of recovery of organisms from these environmental sites varied (Table III) and probably bears little direct relation to the extent of
176 Table
P. J. Sanderson II.
Organisms
and P. Rawal
causing episodes of urinary-tract infection and number of occasions same organism recovered from bedding or bath towels No. of occasions recovered (no. of examinations) from No. of episodes of urinary-tract infection
Organism Klebsiella pneumoniae Escherichia coli Enterobacter cloacae Serratia marcescens Pseudomonas spp. Proteus mirabilis Acinetobacter calcoaceticus anitratus K. ozaenae Total
Table
III.
Extent
of contamination
bath towel
9
7
(9)
2 3 2 2
4 3 0 0
(6) (3)
(2) (2)
4 0 1 3 0 0
:
1
(1)
1 0
(1) (1)
30
20
(30)
9
(20)
of patients’ bedding (total to sample each bed)
No. of cfus
bedding
cfus from
(5) (3)
(6) (3) (1) (0)
three sweep plates used
No. of patients
>30 1 l-30 CklO
5 11 4
Total
20
contamination. When sweep plates of bedding and bath towels were positive, most bore between l-10 cfus of the urinary organism, giving a totality of cfus on the three plates as recorded in the table. There was little evidence of cross-infection between the urinary tracts of patients during the course of the study, but cross-infection between environmental sites and between environmental sites and urinary tracts did occur. A serotype 8 strain of E. cloacae was found on the bedding, bath towel, face cloth, clothing and bedside table of a patient 10 days after a strain with the same antibiogram, API profile and serotype caused urinary infection in a neighbouring patient. Similarly, a strain of K. pneumoniae was found on the bedding of a patient 2 days before an identical strain was found to be causing urinary infection in a neighbouring patient. On three occasions indistinguishable organisms caused urinary infection in two separate patients, but at intervals of 2.5 and 34 days, and 3 months; no simultaneous infections with indistinguishable organisms occurred in different patients. Precautions against cross-infection consisted of emphasis on handwashing before and after catheterization by both patients and staff.
Environmental
contamination
in UT1
177
Separate urine jugs were labelled and used for each patient and were disinfected after each use in a washer with a pasteurizing cycle. Catheterization was a sterile procedure using a sterile disposable catheter on each occasion. Relapse of infection occurred in two patients at intervals of 14 and 67 days. The antibiotics tested for antibiogram determination were amoxycillin, trimethoprim, nalidixic acid, nitrofurantoin, cephalexin and gentamicin. The six strains of E. coli showed a mean of two resistances. Four strains of K. pneumoniae, of three different serotypes, were resistant to amoxycillin, trimethoprim, nalidixic acid and nitrofurantoin. The other five strains were resistant to fewer agents. The one strain of Acinetobacter was resistant to all antibiotics except nalidixic acid, and the three strains of Serratia were resistant to all antibiotics except gentamicin in one and amoxycillin and gentamicin in two. Four isolates of Enterobacter were resistant to three agents and two to two agents. Discussion
The results of this study demonstrate that organisms causing urinary-tract infection in spinally-injured patients are also recoverable from the patients’ immediate environment. The patients’ bedding yielded the urinary organism in 20 of 30 (66%) episodes of urinary infection, as did nine of 20 (45%) of the bath towels sampled. Face cloths and the outer clothing were found to be less frequently contaminated but urinary organisms were also recoverable from bedside tables and wheelchairs. The techniques used to sample the bedding and other surfaces were probably insensitive, and more widespread contamination of both the inanimate environment and of the personal belongings of our patients may well have occurred. The large numbers of organisms occurring in urine during urinary-tract infection may act as the main source for environmental contamination. However, it is also possible that perineal colonization is responsible for both urinary infection and environmental contamination. Fawcett et al. (1986) showed colonization of the perinea and groins of spinal cord injured patients by Gram-negative bacilli associated with urinary infection, and demonstrated the organism causing urinary infection on the skin of the perineum before it appeared in the urine in three patients. Our study did not examine the skin flora of the perineum but previous work in our unit supports the idea that urinary infection originates from organisms colonizing the perineum. Of the organisms causing urinary infections in the patients we studied, the predominant species were K. pneumoniae, E. coli and E. cloacae. None of these were multiply resistant but most showed a varying pattern of individual resistances to the antibiotics tested. Resistance to amoxycillin was high, occurring in 22 of the 30 strains, and resistance to nitrofurantoin
178
P. J. Sanderson
and
P. Rawal
and nalidixic acid occurred in 13 strains each. The single strain of acinetobacter was multiply resistant, being the only isolate to show resistance to gentamicin. Two aspects of the prevention of cross-infection in spinal injuries units, and in other areas where patients with urinary-tract infection are nursed, arise from these findings. First, contamination of hands may occur from a much wider range of sources than the urine, catheter and drainage bags. Contact of hands with the patient’s bedding, bedside furniture, wheelchair, clothing and bathroom supplies may lead to their contamination by organisms currently causing urinary infection and should be avoided where possible. Hand contact with these fomites should be followed by hand washing or skin disinfection. Secondly, other patients in the unit, particularly those mobilized in wheelchairs, may touch and handle items in the immediate environment of neighbouring patients. Thev may also share bathroom towels and other contaminated objects. This may lead to contamination of patients’ hands, and since many patients catheterize themselves, allow organisms to gain rapid access to the urinary tract. Consequently, it is equally important to emphasize hand washing among patients as among staff. \$‘e wish Laboratories,
to thank PHLS,
Dr T. Pitt, for biotyping
Division of Hospital many of the strains
Infection, Central Public described in this paper.
Health
References Dienes, L. (1946). ReproductiLre processes in Proteus cultures. Proceedings of the Society for Experimental Biology and Medtcine 63, 265-270. Fawcett, C., Chawla, J. C., Quoraishi, A. 8i Stickler, D. J. (1986). A study of the skin flora of spinal cord injured patients. Journal of Hospital Infectton 8, 149-158. Gilmore, D. S., Schick, D. G. & Rlontgomerie, J. Z. (1982). Pseudomonas aeruginosa and Klebsiella pneumoniae on the perinea of males wrth spinal cord injuries. Journal of Clinical Mtcrobiology 16, 865-867. Montgomerie, J. Z. & Morrow, J. IV. (1980). Long term Pseudomonas colomzatron in spinal cord injury patients. American Journal of Epidemiology 112, 508-5 17.
of Hospital
Infection
Contamination injured patients
Philip Royal
National
(1987)
10, 173-178
of the environment of spinal cord by organisms causing urinary-tract infection J. Sanderson
Orthopaedic
and Pratima
Hospital,
Brockley
Accepted for publication
Rawal
Hill,
14 November
Stanmore
HA7 4LP
1986
Summary: Various environmental sites closely associated with spinallymjured patients were examined for contamination by organisms concurrently causing urinary infection. Of 30 episodes studied, the same organism was recovered from bedding on 20 occasions, from nine of 20 bath towels and less frequently from face cloths, clothing, wheelchairs and bedside units. The results indicate that contact with the immediate environment of spinal patients with urinary infection may lead to contamination of hands, and confirm and expand the need for handwashing by patients and staff.
Introduction Spinally-injured patients undergoing bladder care by indwelling or intermittent catheterization and condom drainage are susceptible to urinary infection and subject to episodes of cross-infection. Organisms are transferred between patients via the hands of staff in contact with urine or drainage apparatus. However, the skin of the perinea and groins of spinally-injured patients has been shown to be frequently and stably colonized with Gram-negative bacilli (Montgomerie & Morrow, 1980; Gilmore, Schick & Montgomerie, 1981). The organisms found were those often associated with hospital-acquired infection of the urinary tract. Fawcett et al. (1986) did not find such organisms at these sites in healthy, ambulant, control subjects. It is possible that environmental contamination of bedding, clothing, seats and towels may result from infected urine and/or perineal colonization. We have investigated various environmental sites of spinal cord injured patients for contamination with organisms causing urinary-tract infection. Patients, Patients Thirty episodes 0195%6701/87/0501i3+06
materials
of urinary-tract
and methods
infection
803 00,O
173
were
investigated
between
2
174
P. J. Sanderson
and P. Rawal
November 198.5 and 21 March 1986 in 17 patients admitted to the Spinal Injuries Unit, Royal National Orthopaedic Hospital, Stanmore. Each patient was undergoing sterile, intermittent bladder catheterization and most wore a penile condom and a urine drainage bag between catheterizations. The patients spent a large part of each day in wheelchairs and received rehabilitation in a separate unit. Urinary infection Urinary-tract infection was diagnosed by using “Dip Slides” (Oxoid Ltd., Basingstoke) which were taken daily in the ward from each patient and examined in the Microbiology Laboratory. Urinary-tract infection was defined as two consecutive counts of > lo5 cfu ml-‘. Positive cultures were sub-cultured on to CLED agar and identified by the -4PI20E system; antibiotic sensitivities were read by the comparative disc method on DST agar (Oxoid Ltd.). Patients received appropriate antibacterial treatment within 24 h of receipt of a positive report. Of the 17 patients studied, 11 had one urinary infection, two had two, one had three and three patients had four infections. In three patients two urinary infections occurred with the same organism, in two of whom there was an interval of at least one month between episodes. In the third patient there were 12 days between infections. All other urinary infections were with different organisms. Environmental sampling Sweep plates were composed of plastic Petri dishes containing cysteine lactose electrolyte deficient (CLED) agar (Lab M, Salford). The surfaces of the pillows and the over and under sheets of each patient’s bedding were individually sampled by sweep plates held so that the edges of the plate lightly scraped the linen surfaces. Patients’ bath towels, face cloths, clothing and wheelchair seats were sampled in the same way. The surfaces and edges of bedside tables and wheelchair arm rests were sampled by rubbing with cotton-tipped swabs, premoistened in transport medium. These were inoculated on to CLED medium within 1 h of sampling. Samples were obtained within 1 or 2 days after diagnosis of urinary infection, sometimes after the start of antibiotic therapy. Bacteriology Sweep plates and inoculated CLED agar plates were incubated at 37°C overnight in air. Colonies resembling those of the organisms recovered from the previous positive urine sample of the patient were sub-cultured on to DST agar for comparison of antibiotic sensitivities by the disc method. Strains with antibiograms identical to that of the urinary isolate were tested in the API20E system and, if the same profile was found, the strain was sent to Reference Laboratories for serotyping or bacteriocin typing. The identity of Proteus strains was tested by the Dienes’ phenomenon (Dienes, 1946).
Environmental
contamination
175
in UT1
Of the 30 organisms isolated from the 30 episodes of urinary infection, 26 were characterized by antibiogram, API profile and serotype or bacteriocin type. Two strains of Proteus mirabilis were characterized by antibiogram, API profile and the Dienes’ phenomenon and one strain of Klebsiella ozaenae by antibiogram and API profile only. One strain of Enterobacter died before exammation could be completed. The corresponding environmental strains (if any) were characterized by the same methods and regarded as identical to the corresponding urinary isolate when antibiogram, API profile, serotype, Dienes’ result or bacteriocin type were the same as in the patient’s urinary isolate. Results
In 20 of the 30 episodes of urinary-tract infection studied an identical organism to that causing the patient’s urinary infection was recovered from the bedding of the patient. Bath towels belonging to patients were examined during episodes of urinary infection on 20 occasions and on nine yielded the patient’s urinary organism. Face cloths, clothing, bedside tables and wheelchairs were sampled less often but all yielded the urinary organism on occasion, albeit with less frequency than in the case of bedding or bath towels (Table I). Table
I. Number
of occasions organisms
causing urinary sites
No. of occasions
recovered
No. of episodes of urinary infection (no. of patients)
Patients’ bedding
Bath towel
Face cloth
Clothing
30(17)
20(30)
9(20)
3(10)
3(13)
infection
recoaeredfrom
(no. of examinations)
encironmental from
Bedside table
Seat
Wheelchair arms & reams
2(17)
3(10)
1(10)
Klebsiella pneumoniae was isolated from nine episodes of urinary-tract infection (Table II). Of the 14 sweep plate samplings obtained from patients’ bedding and bath towels during these nine episodes, 11 yielded an identical strain of K. pneumoniae to that found in the patient’s urinary tract. The same strain of Escherichia coli as in the urine was recovered from five of nine samplings of patient’s bedding and bath towels. Similar recovery rates were obtained for Enterobacter cloacae (five of 12 samplings), Serratia marcescens (six of six), Acinetobacter calcoaceticus var. anitratus (two of two) and K. ozaenae (one of two). The extent of recovery of organisms from these environmental sites varied (Table III) and probably bears little direct relation to the extent of
176 Table
P. J. Sanderson II.
Organisms
and P. Rawal
causing episodes of urinary-tract infection and number of occasions same organism recovered from bedding or bath towels No. of occasions recovered (no. of examinations) from No. of episodes of urinary-tract infection
Organism Klebsiella pneumoniae Escherichia coli Enterobacter cloacae Serratia marcescens Pseudomonas spp. Proteus mirabilis Acinetobacter calcoaceticus anitratus K. ozaenae Total
Table
III.
Extent
of contamination
bath towel
9
7
(9)
2 3 2 2
4 3 0 0
(6) (3)
(2) (2)
4 0 1 3 0 0
:
1
(1)
1 0
(1) (1)
30
20
(30)
9
(20)
of patients’ bedding (total to sample each bed)
No. of cfus
bedding
cfus from
(5) (3)
(6) (3) (1) (0)
three sweep plates used
No. of patients
>30 1 l-30 CklO
5 11 4
Total
20
contamination. When sweep plates of bedding and bath towels were positive, most bore between l-10 cfus of the urinary organism, giving a totality of cfus on the three plates as recorded in the table. There was little evidence of cross-infection between the urinary tracts of patients during the course of the study, but cross-infection between environmental sites and between environmental sites and urinary tracts did occur. A serotype 8 strain of E. cloacae was found on the bedding, bath towel, face cloth, clothing and bedside table of a patient 10 days after a strain with the same antibiogram, API profile and serotype caused urinary infection in a neighbouring patient. Similarly, a strain of K. pneumoniae was found on the bedding of a patient 2 days before an identical strain was found to be causing urinary infection in a neighbouring patient. On three occasions indistinguishable organisms caused urinary infection in two separate patients, but at intervals of 2.5 and 34 days, and 3 months; no simultaneous infections with indistinguishable organisms occurred in different patients. Precautions against cross-infection consisted of emphasis on handwashing before and after catheterization by both patients and staff.
Environmental
contamination
in UT1
177
Separate urine jugs were labelled and used for each patient and were disinfected after each use in a washer with a pasteurizing cycle. Catheterization was a sterile procedure using a sterile disposable catheter on each occasion. Relapse of infection occurred in two patients at intervals of 14 and 67 days. The antibiotics tested for antibiogram determination were amoxycillin, trimethoprim, nalidixic acid, nitrofurantoin, cephalexin and gentamicin. The six strains of E. coli showed a mean of two resistances. Four strains of K. pneumoniae, of three different serotypes, were resistant to amoxycillin, trimethoprim, nalidixic acid and nitrofurantoin. The other five strains were resistant to fewer agents. The one strain of Acinetobacter was resistant to all antibiotics except nalidixic acid, and the three strains of Serratia were resistant to all antibiotics except gentamicin in one and amoxycillin and gentamicin in two. Four isolates of Enterobacter were resistant to three agents and two to two agents. Discussion
The results of this study demonstrate that organisms causing urinary-tract infection in spinally-injured patients are also recoverable from the patients’ immediate environment. The patients’ bedding yielded the urinary organism in 20 of 30 (66%) episodes of urinary infection, as did nine of 20 (45%) of the bath towels sampled. Face cloths and the outer clothing were found to be less frequently contaminated but urinary organisms were also recoverable from bedside tables and wheelchairs. The techniques used to sample the bedding and other surfaces were probably insensitive, and more widespread contamination of both the inanimate environment and of the personal belongings of our patients may well have occurred. The large numbers of organisms occurring in urine during urinary-tract infection may act as the main source for environmental contamination. However, it is also possible that perineal colonization is responsible for both urinary infection and environmental contamination. Fawcett et al. (1986) showed colonization of the perinea and groins of spinal cord injured patients by Gram-negative bacilli associated with urinary infection, and demonstrated the organism causing urinary infection on the skin of the perineum before it appeared in the urine in three patients. Our study did not examine the skin flora of the perineum but previous work in our unit supports the idea that urinary infection originates from organisms colonizing the perineum. Of the organisms causing urinary infections in the patients we studied, the predominant species were K. pneumoniae, E. coli and E. cloacae. None of these were multiply resistant but most showed a varying pattern of individual resistances to the antibiotics tested. Resistance to amoxycillin was high, occurring in 22 of the 30 strains, and resistance to nitrofurantoin
178
P. J. Sanderson
and
P. Rawal
and nalidixic acid occurred in 13 strains each. The single strain of acinetobacter was multiply resistant, being the only isolate to show resistance to gentamicin. Two aspects of the prevention of cross-infection in spinal injuries units, and in other areas where patients with urinary-tract infection are nursed, arise from these findings. First, contamination of hands may occur from a much wider range of sources than the urine, catheter and drainage bags. Contact of hands with the patient’s bedding, bedside furniture, wheelchair, clothing and bathroom supplies may lead to their contamination by organisms currently causing urinary infection and should be avoided where possible. Hand contact with these fomites should be followed by hand washing or skin disinfection. Secondly, other patients in the unit, particularly those mobilized in wheelchairs, may touch and handle items in the immediate environment of neighbouring patients. Thev may also share bathroom towels and other contaminated objects. This may lead to contamination of patients’ hands, and since many patients catheterize themselves, allow organisms to gain rapid access to the urinary tract. Consequently, it is equally important to emphasize hand washing among patients as among staff. \$‘e wish Laboratories,
to thank PHLS,
Dr T. Pitt, for biotyping
Division of Hospital many of the strains
Infection, Central Public described in this paper.
Health
References Dienes, L. (1946). ReproductiLre processes in Proteus cultures. Proceedings of the Society for Experimental Biology and Medtcine 63, 265-270. Fawcett, C., Chawla, J. C., Quoraishi, A. 8i Stickler, D. J. (1986). A study of the skin flora of spinal cord injured patients. Journal of Hospital Infectton 8, 149-158. Gilmore, D. S., Schick, D. G. & Rlontgomerie, J. Z. (1982). Pseudomonas aeruginosa and Klebsiella pneumoniae on the perinea of males wrth spinal cord injuries. Journal of Clinical Mtcrobiology 16, 865-867. Montgomerie, J. Z. & Morrow, J. IV. (1980). Long term Pseudomonas colomzatron in spinal cord injury patients. American Journal of Epidemiology 112, 508-5 17.