Prevalence, Molecular Characterization and Antibiotic Susceptibility of Reproductive Tract Pathogens Isolated from Women of Child Bearing

Abstract

Reproductive tract infections (RTIs) are a major public health problem especially in the developing world. As part of measures to control the spread of these infections, the World Health Organization recommended syndromic management. This study set out to determine the prevalence patterns, molecular characteristics and antibiotic susceptibility of reproductive tract pathogens isolated from women of child bearing age with the aim of contributing useful information to policy formulation regarding treatment and management of these infections. The study was a laboratory - based cross sectional prospective study conducted at the University of Port Harcourt Teaching Hospital (UPTH), a tertiary health facility and a major referral centre with obstetric and gynaecological services. The sample size for the study was determined using StatMate version 2.0 and results were analysed using Excel 2007 and SPSS version 17. A sample size of 500 was determined to be adequate and has a 99% power to detect a difference between group mean and a hypothetical mean of 0.96 with an alpha (α) level of 0.05 (2-tailed) and a beta (β) error of 1%. Two hundred and sixty five pregnant women attending antenatal clinic and two hundred and forty two non-pregnant women attending general outpatient clinic were enrolled into the study over a 6-month period from April to September, 2011.The non-pregnant women served as controls. The Research and Ethics Committee of UPTH approved the study and all prospective participants gave their voluntary informed consent before they were enrolled into the study. A standard structured questionnaire was used to collect socio-demographic data of all participants. Two samples (one cervical and one high vaginal swab (HVS)) were collected from each of 507 participants enrolled into the study. The high vaginal swab samples were cultured using standard microbiological and biochemical methods. Antibiotic susceptibility testing was done and the isolated organisms were identified using the Biomieriux API ® staph testing system for staphylococci and API® Rapid 32 for enterobacteriaceae. Genomic DNA was extracted from the cervical swabs using Qiagen® DNA extraction kit, which was stored at -200 C and later used for the detection of the organisms of interest using standard polymerase chain reaction (PCR) technique and agarose gel electrophoresis. The organisms investigated with this method included Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Streptococcus agalactiae, Trichomonas vaginalis and Candida albicans . From the socio-demographic data, the mean age of the participants was 30.32 ± 8.5 years, mean age at sexual debut was 20.74 ± 5.6 years while the mean age at marriage was 25.23 ± 6.2 years. Forty nine (27.7 %) reported experiencing vaginal discharge, 46(26 %) had itching, 36(20.34%) had lower abdominal pain and 5(2.8%) had painful urination. Forty two percent (44) of the pregnant and 58% (60) of the non-pregnant women had staphylococcal bacterial infections. Out of the 108 bacteria isolated, 69% (70) were Staphylococcus aureus . Sixty eight percent and 32% of the pregnant and non-pregnant women respectively had yeast infections. From the pregnant women 35.5% (22) and 72% (47) of Ureaplasma parvum and Ureaplasma urealyticum respectively were isolated, while 65.6% (42) and 27% (18) were isolated in the non-pregnant women. Mycoplasma hominis was present in both populations, with 43.3% (13) in pregnant and 58.7% (17) in non-pregnant women respectively, while only two( 2) samples of Chlamydia trachomatis were isolated in the non-pregnant females. Some participants had multiple infections. Prevalence rates ranged from zero for N. gonorrhoeae and T. pallidum , to 26.2 % for C. albicans. A significant association was observed between pregnancy status and type of infections but none was seen between abortion status and infections (p ≤ 0.05). The S. aureus species isolated showed multiple drug resistance. The isolated S. aureus showed highest sensitivity to laevofloxacin (37.5 %) and ceftriaxone (35.6 %) followed by clindamycin (20.2 %). There was a high level of resistance to ampicillin (47.1 %), cefixime (41.3 %), norfloxacin (38.5 %), ciprofloxacin (28.8 %), ofloxacin (23.1 %), gentamicin (23.1 %) and erythromycin (21.2 %). A trend of increasing resistance to the older quinolone antibiotics was seen and a high level of resistance to cefixime , a newer generation oral cephalosporin observed. Based on the findings of this study, it is recommended that routine screening for RTIs be incorporated into antenatal services at least, at the tertiary centres and that all necessary steps be taken to control the problem of antibiotic resistance and improve reproductive health and pregnancy outcomes.