Phenotypic and molecular characterization of multiple-resistant gram-negative bacteria in urine of pregnant women attending antenatal clinic of Mother and Child hospital, Ondo, Nigeria

Phenotypic and molecular characterization of multiple antibiotic resistant Gram-negative bacteria in urine samples of pregnant women in Mother and Child Hospital, Nigeria was reported. In the study, 407 apparently healthy pregnant women were recruited. Structured questionnaire was administered to the patients to obtain their socio-demographic information and the medical history. Urine samples were collected, processed and analysed using standard microbiological procedures. Detailed identification of the bacteria isolates was done using biochemical characterization using Bergey’s Manual of Determinative Bacteriology and Analytical Profile Index (API) Kit. The antimicrobial susceptibility testing of the bacteria isolates was carried out using the Kirby-Bauer’s disk diffusion technique. Detection of the beta lactamase resistance genes (bla CTX-M and Tet A) was done by polymerase chain reactions (PCR) with appropriate primers. The following Gram-negative bacteria were recovered comprising Pseudomonas aeruginosa 48 (34.0%), Escherichia coli 30 (21.3%), Klebsiella sp. 27 (19.1%), Proteus sp. 15 (10.6%), Salmonella sp. 8 (5.7%), Providencia rettgeri, 4 (2.8%) and Enterobacter cloacae 4(2.8%) and other enterobacteriaceae 5 (3.5%). Resistance of the isolates to antibiotics used varied greatly among the isolates. Resistance to antibiotics was highest with P. aeruginosa having 100% to augumentin, tetracylines, amoxicillin, nitrofurantoin, cotrimoxazole, ceftriazone, cefixime (97.9%) and cefuroxime (95.8%). There was diversity in the multiple antibiotic resistance (MAR) patterns among the isolates with 12 different MAR patterns observed. The selected P. aeruginosa profiled for resistance genes harboured bla-CTX-M (585bp) and Tet A (954bp) genes. The multiple antibiotic resistant bacteria recovered could pose great health challenge to the pregnant women and the unborn foetus.   Key words: Gram negative bacteria, antibiotics, enterobacteriaceae, resistance genes.