Retrospective Analysis of Gram-Negative Bacteria Isolated at a Tertiary Hospital in Maiduguri, Nigeria

Background: Gram negative bacteria accounts for significant proportion of hospital and community associated infections responsible for significant proportion of hospital admission, and associated increased level of antibiotic resistance pattern. Based on this information, we retrospectively analyzed the prevalence and resistance pattern of gram negative bacteria isolated from clinical specimens submitted in a tertiary hospital in Maiduguri, Nigeria.

Methodology: Bacteriological data of gram negative bacteria isolates recovered from clinical specimens submitted to medical microbiology laboratory of University of Maiduguri Teaching Hospital (UMTH) between 2007-2011were extracted and analyzed. A total of 36,800clinical specimens were examined.

Results: The prevalence level of gram-negative bacteria isolates was 24.09% (8865/36,800), majority (29.16%, n=2585) of the isolates were recovered from wound specimens. Escherichia coli accounted for 31.8% (n=2823) of the total isolates. High susceptibility was observed with fluoroquinolones, aminoglycosides and cephalosporin tested, and resistance with cotrimoxazole and chloramphenicol. Overall, 7.6% (n=671) of the gram negative isolates exhibited multidrug resistance pattern, Escherichia coli accounted for 39.9% (268/671) of the multidrug resistant isolates.

Conclusion: The study highlights epidemiological characteristics of the gram-negative bacteria isolated in our hospital, with prevalence level of 24.09% and diverse isolation pattern which affirmed gram-negative bacteria clinical implication in hospital and community associated infections. In addition, the multidrug resistance pattern level of 7.6% is an indication for laboratory personnel to be aware of possible emergence of multidrug resistant strain among gram-negative isolated in the hospital