ASYMPTOMATIC BACTERIURIA IN PREGNANT WOMEN ATTENDING ANTENATAL CLINICS IN THREE HOSPITALS IN KANO, NIGERIA

ABSTRACT

Asymptomatic bacteriuria in pregnancy is the significant presence of bacteria in the urine of pregnant women without the clinical symptoms of urinary tract infection (UTI). This study was designed to highlight the prevalence of asymptomatic bacteriuria among pregnant women in Kano, Nigeria. Samples of urine were randomly obtained from 310 women attending antenatal clinics in 3 major hospitals. These were subjected to microbiological and cultural tests. The bacteria isolated were characterized using standard methods. Using 105cfu/ml as significant level of bacteriuria, prevalence was found to be 15.2%. Isolated organisms include Proteus spp.,  23  (49%),  Escherichia  coli,  17  (36%),  Staphylococcus  aureus,  3  (6.4%),

Pseudomonas aeruginosa, 2 (4.3%), and Klebsiella spp., 2 (4.3%). The age group 25- 30 years had the highest prevalence (24.2%) with respect to age; the housewives had the highest prevalence (57.4%) with respect to occupational status. Pregnant women in the last trimester had the highest prevalence (18.2%). The result of antimicrobial susceptibility of Proteus spp. and E. coli to some of the commonly prescribed antibiotics showed resistance to amoxicillin, ciprofloxacin, ceftriaxone, nitrofurantoin, gentamicin, levofloxacin, cotrimoxazole, amoxicillin/clavulanic acid, nalidixic acid and tetracycline (47-100%). S. aureus showed resistance to ceftriaxone, nitrofurantoin, amoxicillin/clavulanic acid, nalidixic acid and tetracycline (66.7- 100%). The multiple antibiotic resistance index (MARI) observed in this study with reference to the tested antibiotics showed that 99.96% of the Proteus spp. isolates have MAR index of 0.2 to 1.0, while 99.97% of the E. coli isolates have MAR index

of 0.2 to 1.0. Proteus spp. isolates were found to express more MR/P+,MR/K- hemagglutinins 12(52.2%) than E. coli isolates 1(5.9%) and showed  significant urease activity ranging from 24-110 (µmol NH3/min/mg protein). They also produced measurable hemolytic activity with titres ranging from 1:2 to 1:256. The E. coli isolates were observed to express more MR/P+,MR/K+ hemagglutinins 9(52.9%) compared to Proteus spp. isolates 8(34.8%). The hemagglutination pattern MR/P-

,MR/K+ was also more observed in E. coli isolates 3(17.6%) than in Proteus spp. isolates 2(8.7%). MR/P-,MR/K- hemagglutinins were expressed by 2(11.8%) isolates of E . coli and 1(4.3%) isolate of Proteus spp. E. coli isolates showed higher range of 1:2 to 1:512 hemolytic activities. The geometric mean of reciprocal hemolytic titres for Proteus spp. isolates was 29.23, while that for E. coli isolates was 31.99. Majority of the E. coli isolates were associated with multi-antibiotic resistance strains, but only 5(five) out of the 17(seventeen) E. coli isolates were seen to harbor plasmids Ec1, Ec2, Ec3, Ec11, Ec13: 3700bp, 4000bp, 4000bp, 2800bp, and 3500bp respectively. There was no amplification of CTX-M2, CTX-M9 (for β-lactam antibiotics),  pCT (for IncK plasmid encoding bla CTX-M ESBL genes), qnrC and qnrS (for fluoroquinolones) genes in all the Proteus spp. and E. coli isolates. However amplification of gyrB gene (for fluoroquinolones) was observed in 5 Proteus spp. isolates (P1, P2, P3, P4 and P5 respectively). Only one Proteus spp. isolate (P3) haboured a plasmid (3500bp), the other four amplified genes in Proteus spp. isolates P1, P2 P4 and P5 might not be plasmid-mediated. In 5 E. coli isolates (Ec1, Ec2, Ec3, Ec4 and Ec5), amplification of gyrB gene was seen, but only 3 of these isolates (Ec1, Ec2, and Ec3) harboured plasmids of 3700bp, 4000bp, and 4000bp molecular sizes

respectively. These amplified genes in Ec4 and Ec5 can be said to be chromosomally mediated and not extra-chromosomal. The implications of these findings in clinical practice are highlighted.