Cantonal Centre for Public Health Zenica, Laboratory for Sanitary and Clinical Microbiology, Fra Ivana Jukica 2/4, 72000 Zenica, Bosnia and Herzegovina
Sir,
Erythromycin and fluoroquinolones are considered the drugs of choice for the treatment of Campylobacter infections. However, recently the broad use of these drugs has led to the development of antimicrobial resistance.1 We conducted a study as there are no published data addressing the antimicrobial susceptibility of campylobacters in Bosnia and Herzegovina.
The Laboratory for Sanitary and Clinical Microbiology of the Cantonal Centre for Public Health in Zenica serves a total population of 432 200: 194 100 in an urban area and 238 100 in a rural area. From May 1 to December 31 1998 stool specimens were received from 1883 consecutive outpatients with sporadic diarrhoea: 1174 children <6 years of age, 252 elementary school students, 155 high school students and 302 adults. The samples were cultured on modified Preston medium (Oxoid, Basingstoke, UK) and incubated in a micro-aerophilic atmosphere at 42°C for 48 h. Campylobacter jejuni and Campylobacter coli were identified using standard microbiological methods.2 Sixty-four isolates of C. jejuni and 24 of C. coli (one isolate from each patient) were tested by a disc diffusion method using MuellerHinton agar supplemented with 5% sheep blood and eight antimicrobials (Oxoid): ciprofloxacin (5 µg), nalidixic acid (30 µg), erythromycin (15 µg), tetracycline (30 µg), ampicillin (10 µg), gentamicin (10 µg), nitrofurantoin (300 µg) using bioDiscs (bioMérieux, France) and azithromycin (15 µg; Becton Dickinson Microbiology Systems, Cockeysville, MD, USA). The frequency of resistance is shown in Figure 1.
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Between 1990 and 1998 (19921995: wartime period) a 7590% decrease in livestock resources was recorded in Bosnia and Herzegovina. The ethnic structure of the Zenica-Doboj Canton population changed due to the great migration during wartime, with Muslims accounting for 82.3% of the population in 1998 (Statistical yearbook of R/F B&H, Sarajevo, 2000). Thus, consumption of pork, customarily associated with C. coli infection, was almost non-existent in this region and may be dismissed as a primary source of C. coli.4 After the war, in 1996, the import of poultry from other countries (mainly from Slovenia) increased: from 43% in 1998 to 70% in 1999. C. coli appeared in high proportion (40%) in poultry meat samples in Slovenia.5 There was a noted increasing trend in ciprofloxacin resistance in C. jejuni human isolates in the 19982000 period (10.538.5%), and 20% resistance to erythromycin in C. coli isolates (I. Berce, Public Health Center, Nova Gorica, Slovenia, personal communication). Enrofloxacin has been licensed for veterinary use since 1990 in Slovenia, but macrolides have not. Consumption of imported chicken is a possible risk factor for the acquisition of a fluoroquinolone-resistant strain, and an increasing frequency of erythromycin resistance was noted at the same time in the human population and in retail raw chicken.6 Thus, quinolone and erythromycin resistance in this region probably reflects the overall resistance of Campylobacter spp. from other countries, rather than the veterinary use of quinolones and macrolides in our region.
Fifty-nine (67%) isolates were from children up to 6 years old. As the use of quinolones is restricted in children, and as erythromycin is not widely used to treat gastrointestinal or other infections in the Zenica-Doboj Canton (10-fold less than the penicillin group of antibiotics; S. Uzunovic-Kamberovic, unpublished results), the extent of resistance to ciprofloxacin and erythromycin is still high and is probably not influenced by overuse of these drugs.
The proportions of erythromycin-resistant C. coli and C. jejuni strains from this study were almost equal. Usually, C. coli is found to be more resistant to erythromycin than C. jejuni.1 In our region, C. coli is frequently isolated from healthy people (36%),5 as well as from symptomatic patients (27.3% in this study). The pig is the favoured host of C. coli and this organism has historically been shown to have a high resistance to macrolides. Macrolides (tylosin) have been permitted as growth promoters in pigs, but not in broilers, and this could explain the lower proportion of erythromycin-resistant strains observed in broilers than in the pigs in some reports.3
Given that C. coli strains in our region probably do not originate from pigs, our observation is unexplained. The environmental transmission cycle of Campylobacter spp. is not fully understood, and antibiotic-resistant bacteria may be isolated from farm animals and the environment.7 This study shows that other sources may be involved in contamination and transmission of Campylobacter infections. Further molecular epidemiological typing work is required to correlate genotypes of fluoroquinolone- and erythromycin-resistant isolates of Campylobacter spp. strains from different sources.
Footnotes
* Tel: +387-32-404-592; Fax: +387-32-404-578; E-mail: selma_kamb{at}yahoo.com
References
1 . Feierl, G., Berghold, C., Fürpaß, T. & Marth, E. (1999). Further increase in ciprofloxacin-resistant Campylobacter jejuni/coli in Styria, Austria. Clinical Microbiology and Infection 5, 5960.[Medline]
2 . Smibert, R. M. (1984). Genus Campylobacter Sebald and Véron 1963. In Bergeys Manual of Systematic Bacteriology, 1st edn (Krieg, N. R. & Holt, J. G., Eds), vol. 1, pp. 1118. Williams & Wilkins, Baltimore, MD, USA.
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Van Looveren, M., Daube, G., De Zutter, L., Dumont, J.-M., Lammens, C., Wijdooghe, M. et al. (2001). Antimicrobial susceptibilities of Campylobacter strains isolated from food animals in Belgium. Journal of Antimicrobial Chemotherapy 48, 23540.
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Uzunovic-Kamberovic, S. (2001). Changes in Campylobacter jejuni/Campylobacter coli carriage rates in the Zenica region of Bosnia and Herzegovina in the pre- and postwar periods. Journal of Clinical Microbiology 39, 2036.
5 . Zorman, T., Mavri, U. & Smole Mozina, S. (2001). Classical and molecular identification of Campylobacter jejuni and Campylobacter coli from poultry samples on Slovenian market. In Program and Abstracts of the Eleventh International Workshop on Campylobacter, Helicobacter and Related Organisms, Freiburg, Germany, 2001. Abstract E-24, p. 40. Urban & Fischer Verlag, Jena, Germany.
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Moore, J. E., Crowe, M., Neville, H. & Crothers, E. (2001). Antibiotic resistance in Campylobacter spp. isolated from human faeces (19802000) and foods (19972000) in Northern Ireland: an update. Journal of Antimicrobial Chemotherapy 48, 4557.
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Piddock, L. J. V., Ricci, V., Stanley, K. & Jones, K. (2000). Activity of antibiotics used in human medicine for Campylobacter jejuni isolated from farm animals and their environment in Lancashire, UK. Journal of Antimicrobial Chemotherapy 46, 3036.
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