Nosocomial infections caused by vancomycin-resistant Enterococcus have become a major problem. Bacteriophage therapy is proposed as a potential alternative therapy. Bacteriophages are viruses that infect bacteria and are ubiquitous in nature. Lytic bacteriophage was isolated from sewage water that infects VREF, the causative agent of endocarditis, bacteraemia, and urinary tract infections (UTIs). The phage produced clear plaques with unique clear morphology and well-defined boundaries. TEM results of phage revealed it to be 108 ± 0.2 nm long and 90 ± 0.5 nm wide. The characterization of bacteriophage revealed that infection process of phage was calcium and magnesium dependent and phage titers were highest under optimum conditions for VREF, with an optimal temperature range of 37–50°C. The maximum growth was observed at 37°C, hence having 100% viability. The latent period for phage was small with a burst size of 512 viral particles per bacterial cell. The phage was tested against various clinical strains and results proved it to be host specific. It can be used as a potential therapeutic agent for VREF infections. The phage efficiently eradicated VREF inoculated in cattle compost, poultry compost, and a soil sample which makes it a potential agent for clearing compost and soil sample.

Enterococcus faecium, is an important nosocomial pathogen with increased incidence of multidrug resistance (MDR) – specifically Vancomycin resistance. E. faecium constitutes the normal microbiota of the human intestine as well as exists in the hospitals and sewage, thus making the microorganism difficult to eliminate. Phage therapy has gained attention for controlling bacterial MDR infections and contaminations. We have successfully isolated from waste water and characterized a lytic bacteriophage STH1 capable of targeting Vancomycin resistant Enterococcus faecium (VREF) with high specificity. The phage was isolated from sewage water of a hospital at district Dera Ismail Khan, Pakistan. Initial characterization showed that magnesium and calcium ions significantly increased phage adsorption to the host. One step growth experiment showed a latent period of 18 min with burst size of 334 virions per cell. Optimal temperature and pH of the phage was 37°C and 7.0, respectively. Phage application to host strain grown in milk and water (treated and untreated) showed that the phage efficiently controlled bacterial growth. The study suggests that the phage STH1 can serve as potential control agent for E. faecium infections in medical facilities and in other environmental contaminations.

Vancomycin resistant Enterococci have emerged rapidly in the recent years leading to treatment failure. The aim of this work was to identify vancomycin resistance determinants; vanA and vanB genes in Enterococci. The blood, urine and throat samples were collected from 150 patients from local hospitals of twin cities of Rawalpindi/Islamabad. Forty-nine phenotypically confirmed isolates were further confirmed by PCR amplification for vancomycin determinants (genes for vanA and vanB) for vancomycin resistant Enterococci. Dependence and frequency distribution of VRE and VSE bacteraemia with respect to age, gender and source was also studied. Phenotypically resistant strains were positive for vanA while negative for vanB. vancomycin susceptible enterococci (VSE) could be isolated more from urine samples as compared to blood whereas vancomycin resistant enterococci (VRE) was found more prevalent in the blood samples (p value= 0.000). VRE was more frequently isolated from patients aged 50 or above whereas VSE prevalence was same in both age groups (p value=0.002). Gender was not found to have any significant impact on VRE or VSE bacteraemia. This study reports vanA gene cluster responsible for resistance in Pakistani population and frequently isolation of VRE from blood samples. Keywords: Enterococcus, Vancomycin resistant Enterococci, Pakistan