Antimicrobial Resistance and Molecular Characterization ofVibrio choleraeO1 During the 2004 and 2005 Outbreak of Cholera in Cameroon

Abstract

There was an outbreak of cholera in Cameroon during 2004 and 2005; the epidemic began in Douala in January 2004 and spread throughout the south of the country. The World Health Organization (WHO) reported 8005 cases in 2004 and 2847 cases in 2005. Five hundred eighty-nine stool samples were received in the Pasteur Centre of Cameroon and 352 were microbiologically confirmed to be positive for Vibrio cholerae O1. Isolated strains were tested for their antimicrobial susceptibilities. All the strains were multidrug resistant and predominantly showed a common resistance pattern at the beginning of the outbreak. Tetracycline, recommended by the WHO for treating cholera in adults, was effective against all the strains tested. Cotrimoxazole (trimethoprim/sulfamethoxazole), previously a first-line treatment in children, was ineffective in vitro for all the clinical isolates and was quickly replaced by amoxicillin. Ampicillin resistance emerged at the end of 2004 and was the leading resistance pattern observed in the second half of 2005. This therefore represented the second major resistance pattern. These two major resistance profiles were not associated with patient characteristics (sex and age) or to the geographic origin of strains. However, there was a highly significant relationship between resistance patterns and the year of isolation (p < 0.001). The strains possessed genes ctxA and ctxB encoding the two cholera toxin subunits and were very closely related, irrespective of their antimicrobial resistance patterns. They were not differentiated by molecular typing methods and gave similar ribotyping and pulsed-field gel electrophoresis patterns.

Antimicrobial Resistance Patterns of Isolated Vibrio cholerae Strains

“…Antibiotics resistance of V. cholerae in other countries is a major problem as well. In a reported survey by the World Health Organization (WHO), all strains were susceptible to tetracycline and resistant to naldixic acid from 2004 to 2005 outbreaks in Cameron (22), which is in agreement with the study of Rahbar et al (18). In another study on the outbreak in South Africa during 2008 -2009, the majority of serotypes were Ogawa.…”

Water sources as reservoirs of Vibrio choleraeO1 and non-O1 strains in Bepanda, Douala (Cameroon): relationship between isolation and physico-chemical factors

“…Doxycycline and amoxicillin were extensively used during this outbreak as drugs of choice in chemotherapy and chemoprophylaxis [23, 24]. Prolonged usage of antibiotics for curative and prophylactic purposes during an epidemic can provoke the emergence and spread of resistant strains into the environment [41].…”

“…Antibiotics tested included: tetracyclines [tetracycline (30 μg), doxycycline (30 μg)], a β-lactam [amoxicillin (30 μg)], β-lactmase inhibitor [augmentin (30 μg)], folic acid synthesis inhibitor [trimethoprim-sulfamethoxazole (cotrimoxazole) (25 μg)], fluoroquinolones [ciprofloxacin (5 μg), ofloxacin (5 μg)] and protein synthesis inhibitor [chloramphenicol (30 μg)]. These antibiotics have been used for treatment during previous outbreaks of cholera in Douala [23, 24] or recommended for cholera treatment [25]. The diameters were compared with the recorded diameters of the control organism E. coli ATCC 25922 to determine susceptibility or resistance.…”

Genetic Characterization of Multidrug-Resistant, Extended-Spectrum- β-Lactamase-Producing Vibrio cholerae O1 Outbreak Strains, Mpumalanga, South Africa, 2008

“…This diarrheal disease is endemic in parts of Africa, Asia, and South and Central America (12). The etiological agents responsible are toxin-producing strains of Vibrio cholerae belonging to serogroups O1 and O139 (9). Aside from rehydration and electrolyte replacement, treatment with antimicrobial agents can decrease the severity of the illness and bacterial shedding (9).…”

“…The etiological agents responsible are toxin-producing strains of Vibrio cholerae belonging to serogroups O1 and O139 (9). Aside from rehydration and electrolyte replacement, treatment with antimicrobial agents can decrease the severity of the illness and bacterial shedding (9). However, antimicrobial-resistant epidemic strains of V. cholerae have been described, consequently raising concerns over the availability and options for antimicrobial treatment (9).…”