Determining Virulence Factors And Genes Coding For Antibiotic Resistance In Enterococci Species Isolated From Pregnant Women In Windhoek, Namibia

ABSTRACT

Purpose of the research: Research into Enterococci is increasingly important as Enterococci was classified as high priority bacteria regarding antimicrobial resistance. Improvements in medical care have also increased the chances of survival of infants with low birth weight. These infants have an increased chance of infection by antibiotic resistant Enterococcus species due to their low birth weight which is further increased by increased hospital stays. In developing countries neonatal meningitis occurs in 0.8-6.1 per 1000 live births. Enterococcus species are one of the causative organisms of late onset neonatal meningitis. Therefore, it is important to monitor colonization of the maternal genitourinary tract to prevent mother to child transmission of these bacteria Objectives: To determine the frequency distribution of Enterococcus species found among pregnant women between 35 and 37 weeks gestation in Windhoek. To establish the antibiotic resistance patterns of the Enterococcus species. To screen for resistance and virulence genes found in Enterococcus isolates. Methodology: A descriptive cross-sectional study done at the antenatal clinic at the Windhoek central hospital in Windhoek. Study population: Pregnant women at 35 – 37 weeks of gestation attending the antenatal clinic at the Windhoek central hospital. Samples were collected from November 2018 to May 2019, in which a total of 193 participants that fit the inclusion criteria participated in the study. An estimated 45 participants refused to participate in the study during this period. Most of the patients (39.9 %) fell with the age range of 25-30 years of age. The average gravidity was 2.31 and the average parity was 2.09. The urine samples amounted to 101 and from a separate group of participants the vaginal swabs and rectal swabs amounted to 92 samples each. Results: The total number of isolates collected from the 193 participants was 20. In rectal swabs 30.8% were Enterococcus faecalis, 7.7% were E. faecium and 61.5% were other Enterococci. In vaginal swabs, 33.3% were E. faecalis and 66.6% were other Enterococcus. Half the isolates found in urine were E. faecalis and the rest was other Enterococci. In these isolates 83.3% were resistant to at least 1 antibiotic. In E. faecalis, 16.7% were positive for vanA, 50.0% were positive for vanB, blaZ were positive for 33.3% and blaR1 were positive for 33.3% isolates. In the E. faecalis isolates 16.7% were positive for agg and 16.7% were positive for gelE. E. faecium did not test positive for any virulence or antibiotic resistance genes. The other Enterococcus species were not confirmed with molecular methods, with 9.1% being positive for vanA, 9.1% positive for vanB, 9.1% positive for tetM, 60.0% positive for blaZ and 9.1% positive for blaR1. Conclusions & Recommendations: The majority of the isolates collected in this study were not the most common species found in human disease namely E. faecalis and E. faecium. This then becomes important to speciate, in order to better treat patients when faced with species with intrinsic resistance. Virulence genes were only found in 3 isolates. Although there are resistance genes present in these isolates, empirical antibiotics would still be effective. This is good considering the global trend of resistance.