- Email: [email protected]
Antibiotic resistant Escherichia coli in a Sudanese hospital
148
Letters
to the Editor
here, when the filters were changed there was a rush of air out of the tubes due to the mechanism of the positive pressure ventilation. Following these findings the ventilatory equipment was sterilized internally and the ward was cleaned thoroughly. Staff carriage resolved spontaneously and there were no further isolations of the organism. This outbreak has a number of interesting features. Further research needs to take place if an opportunity arises but some important factors seem to be of value: (1) The acinetobacter was unusually pathogenic. (2) The patients did not respond clinically to imipenem despite in-vitro sensitivity. (3) Apparent in-vitro sensitivity to amikacin was misleading as resistance appeared immediately it was administered to an infected patient. (4) The organism colonized intravenous and endotracheal plastic devices. (5) The acinetobacter was able to pass through the ventilatory filters and it may have been due to this that dissemination between patients took place. (6) Staff became colonized with the acinetobacter. (7) Infection control procedures were successful in removing the bacterium from the ICU but were expensive to carry out.
S. Dealler
Department
of Medical Microbiology, Burnley General Hospital, Burnley BBll 4RL, UK Email: [email protected]
References 1. Koeleman JGM, Parlevliet GA, Kijkshoorn L et al. Nosocomial resistant Acinetobacter baumanni on a surgical ward: epidemiology acquisition. J Hasp Infect 1997; 37: 113-l 23. 2. Im SWK, Fung JPH, So SY, Yu DYC. Unusual dissemination ventilators. Anaesthesia 1982; 37: 1074-1077.
outbreak and risk
of multifactors for
of pseudomonads
by
Sir, Antibiotic
resistant
Escherichia
coli
in a Sudanese hospital
Antimicrobial resistance is an increasing problem in public health in much of tropical Africa, but only limited data are available from hospitalized patients.’ We have undertaken a survey of antimicrobial resistance of isolates of Escherichia coli from clinical specimens (urine and wound swabs) from hospitalized adult patients in Khartoum, Sudan. Isolates were obtained from 80 patients, 62 from urinary tract infections and 18 from wound
Letters Table
No
(%)
I.
Patterns
of resistant
of resistance
to the Editor
to individual
antibiotics
isolates
Ap
80
75 (94)
5
antimicrobials
Resistance occurring
(5%)
patterns in 2four
and
n
No
No (‘%a) of isolates resistant to 2 three
149
Tc
resistance C
(&
::,
G
Na
(i!)
(1)
of antimicrobials 4 3
(i)
(it)
(&
Resistance
pattern
No
(‘Xl,
of isolates Ap Ap Ap Ap Ap
Ap, ampicillin;
multiple
C;, gcntamicin;
‘I‘c, tctracyclinc;
Na, nalidixic
acid;
‘I’c Tc Tc Tc Tc
C C C G
Na G
5 X 22 4 1X
c’, chloramphenicol
infections. Antimicrobial sensitivity was tested by disc diffusion using the following discs: ampicillin (10 pg); tetracycline (10 pg); chloramphenicol (10 pg); gentamicin (10 pg); nalidixic acid (30 pg). Transfer of antibiotic resistance was investigated by broth mating, and plasmid DNA of donors and transconjugants was extracted by the method of Birnboim and Daly.’ The results shows a high prevalence of resistance to commonly used antimicrobial agents (Table I). Resistance was most common to ampicillin (94% of isolates), tetracycline (85%) and chloramphenicol (54%). Forty-six (57%) of the patients had isolates resistant to three or more antimicrobial
Table
II.
Resistance
puttrvns
Donor
R pattern
Resistances
Ap Tc Ap Tc .4p Tc
C G C G C
Ap Ap
Ap ‘rc <; hp
AP ‘1-c
Tc
Ap TC C G Tc Tc
‘l-c xp ‘l-c ‘G ‘I’c
C
and plasmids transferred
transferred
150 strains
examined)
Molecular weight (I\lDa) of transferred plasmids (,V) = number of strains with plasmid 9X 120 10X 9X 30 98 9x 90
(1) (1) 95 (1) mD (8) mD (8) mD (1) (1) (2) (2) 82 (1) 74 98
(ij
7x
150
Letters
to the Editor
agents. Table I also shows the multiple resistance patterns. The most commonly occurring was resistance to ampicillin, tetracycline and chloramphenicol. Conjugation experiments demonstrated that much of this resistance was transferable (Table 11). The most commonly transferred resistance pattern was resistance to ampicillin, tetracycline and chloramphenicol, and was transferred by single plasmids of molecular weights 108 MDa, 98 MDa and 30 MDa. Plasmids of molecular weight 98 MDa were the most common conjugative plasmids, transferring several different resistance patterns. These results are the first published data of antimicrobial resistance in hospitalized patients from the Sudan. They demonstrate a high prevalence of resistance to commonly available antimicrobial agents, and show that much of this resistance is transferable. We have previously demonstrated a high prevalence of multiple resistance in enteric flora in non-hospitalized children in the Sudan,3 and the two studies suggest that transferable multiple resistance is a problem of importance in both hospitals and the community. Studies in other tropical areas have shown a similar high prevalence of transferable resistance in Enterobacteriaceae.4,5 Antimicrobial resistance in tropical countries is associated with suboptimal prescribing, and the potential for spread of resistant isolates in environments with inadequate water and sanitation. There is a need to develop surveillance of hospital infections and resistance prevalence studies in the tropics to provide data on which control strategies can be based.’ H. A. Musa* P. Shears+
*Department
oLnEefi;;yl . .
ffiUi;tJi$ug;
P.O. Box 102: Khartoum, Sudan j-Department of Medical Microbiology, Royal Liverpool Hospital, Prescot Street, Liverpool L 7 8XW, UK References 1. Kunin 2. 3.
4. 5. 6.
KM. Antibiotic resistance: a world health problem we cannot ignore. Ann Intern Med 1983; 99: 859460. Birnboim HC, Daly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res 1979; 7: 1513-1523. Shears P, Suliman G, Hart CA. Occurrence of multiple antibiotic resistance and R plasmids in Enterobacteriaceae isolated from children in the Sudan. Epidemiol Znfect 1988; 100: 73-81. Levy SD, Hedges RW, Sullivan F, Medeiros AA. Multiple antibiotic resistance plasmids in Enterobacteriaceae J Antimicrob Chemother 1985; 16: 7-16. Young HK, Jesudason MV, Koshi G, Aymes SGB. Trimethoprim resistance amongst urinary pathogens in South India. J Antimicrob Chemother 1986; 17: 615-621. Ponce-de-Leon S. The needs of developing countries and the resources required. J Hasp Infect 1991; 18 (Suppl. A): 376-381.
Letters
to the Editor
here, when the filters were changed there was a rush of air out of the tubes due to the mechanism of the positive pressure ventilation. Following these findings the ventilatory equipment was sterilized internally and the ward was cleaned thoroughly. Staff carriage resolved spontaneously and there were no further isolations of the organism. This outbreak has a number of interesting features. Further research needs to take place if an opportunity arises but some important factors seem to be of value: (1) The acinetobacter was unusually pathogenic. (2) The patients did not respond clinically to imipenem despite in-vitro sensitivity. (3) Apparent in-vitro sensitivity to amikacin was misleading as resistance appeared immediately it was administered to an infected patient. (4) The organism colonized intravenous and endotracheal plastic devices. (5) The acinetobacter was able to pass through the ventilatory filters and it may have been due to this that dissemination between patients took place. (6) Staff became colonized with the acinetobacter. (7) Infection control procedures were successful in removing the bacterium from the ICU but were expensive to carry out.
S. Dealler
Department
of Medical Microbiology, Burnley General Hospital, Burnley BBll 4RL, UK Email: [email protected]
References 1. Koeleman JGM, Parlevliet GA, Kijkshoorn L et al. Nosocomial resistant Acinetobacter baumanni on a surgical ward: epidemiology acquisition. J Hasp Infect 1997; 37: 113-l 23. 2. Im SWK, Fung JPH, So SY, Yu DYC. Unusual dissemination ventilators. Anaesthesia 1982; 37: 1074-1077.
outbreak and risk
of multifactors for
of pseudomonads
by
Sir, Antibiotic
resistant
Escherichia
coli
in a Sudanese hospital
Antimicrobial resistance is an increasing problem in public health in much of tropical Africa, but only limited data are available from hospitalized patients.’ We have undertaken a survey of antimicrobial resistance of isolates of Escherichia coli from clinical specimens (urine and wound swabs) from hospitalized adult patients in Khartoum, Sudan. Isolates were obtained from 80 patients, 62 from urinary tract infections and 18 from wound
Letters Table
No
(%)
I.
Patterns
of resistant
of resistance
to the Editor
to individual
antibiotics
isolates
Ap
80
75 (94)
5
antimicrobials
Resistance occurring
(5%)
patterns in 2four
and
n
No
No (‘%a) of isolates resistant to 2 three
149
Tc
resistance C
(&
::,
G
Na
(i!)
(1)
of antimicrobials 4 3
(i)
(it)
(&
Resistance
pattern
No
(‘Xl,
of isolates Ap Ap Ap Ap Ap
Ap, ampicillin;
multiple
C;, gcntamicin;
‘I‘c, tctracyclinc;
Na, nalidixic
acid;
‘I’c Tc Tc Tc Tc
C C C G
Na G
5 X 22 4 1X
c’, chloramphenicol
infections. Antimicrobial sensitivity was tested by disc diffusion using the following discs: ampicillin (10 pg); tetracycline (10 pg); chloramphenicol (10 pg); gentamicin (10 pg); nalidixic acid (30 pg). Transfer of antibiotic resistance was investigated by broth mating, and plasmid DNA of donors and transconjugants was extracted by the method of Birnboim and Daly.’ The results shows a high prevalence of resistance to commonly used antimicrobial agents (Table I). Resistance was most common to ampicillin (94% of isolates), tetracycline (85%) and chloramphenicol (54%). Forty-six (57%) of the patients had isolates resistant to three or more antimicrobial
Table
II.
Resistance
puttrvns
Donor
R pattern
Resistances
Ap Tc Ap Tc .4p Tc
C G C G C
Ap Ap
Ap ‘rc <; hp
AP ‘1-c
Tc
Ap TC C G Tc Tc
‘l-c xp ‘l-c ‘G ‘I’c
C
and plasmids transferred
transferred
150 strains
examined)
Molecular weight (I\lDa) of transferred plasmids (,V) = number of strains with plasmid 9X 120 10X 9X 30 98 9x 90
(1) (1) 95 (1) mD (8) mD (8) mD (1) (1) (2) (2) 82 (1) 74 98
(ij
7x
150
Letters
to the Editor
agents. Table I also shows the multiple resistance patterns. The most commonly occurring was resistance to ampicillin, tetracycline and chloramphenicol. Conjugation experiments demonstrated that much of this resistance was transferable (Table 11). The most commonly transferred resistance pattern was resistance to ampicillin, tetracycline and chloramphenicol, and was transferred by single plasmids of molecular weights 108 MDa, 98 MDa and 30 MDa. Plasmids of molecular weight 98 MDa were the most common conjugative plasmids, transferring several different resistance patterns. These results are the first published data of antimicrobial resistance in hospitalized patients from the Sudan. They demonstrate a high prevalence of resistance to commonly available antimicrobial agents, and show that much of this resistance is transferable. We have previously demonstrated a high prevalence of multiple resistance in enteric flora in non-hospitalized children in the Sudan,3 and the two studies suggest that transferable multiple resistance is a problem of importance in both hospitals and the community. Studies in other tropical areas have shown a similar high prevalence of transferable resistance in Enterobacteriaceae.4,5 Antimicrobial resistance in tropical countries is associated with suboptimal prescribing, and the potential for spread of resistant isolates in environments with inadequate water and sanitation. There is a need to develop surveillance of hospital infections and resistance prevalence studies in the tropics to provide data on which control strategies can be based.’ H. A. Musa* P. Shears+
*Department
oLnEefi;;yl . .
ffiUi;tJi$ug;
P.O. Box 102: Khartoum, Sudan j-Department of Medical Microbiology, Royal Liverpool Hospital, Prescot Street, Liverpool L 7 8XW, UK References 1. Kunin 2. 3.
4. 5. 6.
KM. Antibiotic resistance: a world health problem we cannot ignore. Ann Intern Med 1983; 99: 859460. Birnboim HC, Daly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res 1979; 7: 1513-1523. Shears P, Suliman G, Hart CA. Occurrence of multiple antibiotic resistance and R plasmids in Enterobacteriaceae isolated from children in the Sudan. Epidemiol Znfect 1988; 100: 73-81. Levy SD, Hedges RW, Sullivan F, Medeiros AA. Multiple antibiotic resistance plasmids in Enterobacteriaceae J Antimicrob Chemother 1985; 16: 7-16. Young HK, Jesudason MV, Koshi G, Aymes SGB. Trimethoprim resistance amongst urinary pathogens in South India. J Antimicrob Chemother 1986; 17: 615-621. Ponce-de-Leon S. The needs of developing countries and the resources required. J Hasp Infect 1991; 18 (Suppl. A): 376-381.