Prevalence, Molecular Characterization And Antibiotic Susceptibility Of Reproductive Tract Pathogens Isolated From Women Of Child Bearing Age

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.