In a developing country like India, where the patients have to bear the cost of their healthcare, the microbiological culture and the sensitivity testing of each and every infection is not feasible. Moreover, there are lacunae in the data storage, management and the sharing of knowledge with respect to the microorganisms which are prevalent in the local geographical area and with respect to the antibiotics which are effective against them. Thus, an empirical therapy for treating infections is imperative in such a setting. The beta lactam antibiotics have been widely used for the empirical treatment of infections since the the discovery of penicillin. Many generations of beta lactams have been launched with, the claims of a higher sensitivity and less resistance, but their sensitivity has drastically decreased over time. Thus, the preference for beta lactams, especially the cephalosporins, as an empirical therapy, among the prescribers was justified initially, but the current sensitivity patterns do not support their empirical use in hospital and community acquired infections. There is a need for increasing the awareness and the attitudinal change among the prescribers, screening of the antibiotic prescriptions, the strict implementation of antibiotic policies in hospital settings, restricting the hospital supplies and avoiding the prescriptions of beta lactams, a regular census of the local sensitivity patterns to formulate and update the antibiotic policies, upgradation of the laboratory facilities for a better and faster detection of the isolates, proper collection, analyses and sharing of the data and the encouragement of the research and development of newer antibiotics with novel mechanisms of action.

The Beta Lactam Antibiotics as an Empirical Therapy in a Developing Country: An Update on Their Current Status and Recommendations to Counter the Resistance against Them.

Background Enterococci form a part of the normal flora of the intestinal tract, the oral cavity, and the vagina, but in recent times, they have become emerging nosocomial pathogens. Their increasing importance is largely due to their resistance to antimicrobials. The therapeutic failures in enterococcal infections are mainly due to the intrinsic as well as transferable drug resistance. The main aim of our study was to estimate the prevalence of the Enterococcus infection and to determine the antibiogram in a tertiary care hospital. Method Enterococcus was isolated from a total of 5555 clinical samples like urine , pus, tissue, blood and body fluids during the period from January to December 2008. The isolates were speciated by using conventional biochemical tests (Facklam and Collins). The antibiotic susceptibility testing was done by the Kirby Bauer disc diffusion method. Confirmation of vancomycin susceptibility was done by the Epsilometer test (E test) to determine the Minimum Inhibitory Concentration (MIC). Result From various clinical samples, 128 Enterococcus species were isolated in a period of one year and the rate of the infection was estimated to be 2.3%. Among the isolates, those of Enterococcus faecalis (E.faecalis) were 97(76%) and the remaining 31(24%) were of Enterococcus faecium (E.faecium). The maximum number of isolates were from pus 55(43%), followed by the isolates from urine 40(31%). The sensitivity pattern of these isolates showed an increased resistance to penicillin, ampicillin and ciprofloxacin. A High Level of Gentamicin Resistance (HLGR) was present in 60 (47% ) isolates of Enterococcus and 35(27%) isolates were intermediately sensitive to vancomycin by the Kirby Bauer disc diffusion method. All the intermediately sensitive isolates to vancomycin were further tested by the E test and they were found to be vancomycin sensitive. Conclusion Various studies have shown an increase in the rate of infection and the antibiotic resistance in the Enterococcus species. There is also a change in the pattern of the Enterococcus infection, with an increase in the isolation rate of E. faecium and other non faecalis Enterococcus species. The Kirby Bauer disc diffusion method is not an accurate method for detecting the Vancomycin Resistant Enterococci (VRE).

The prevalence and the characterization of the enterococcus species from various clinical samples in a tertiary care hospital.

Background: Multi-drug-resistant Enterococci colonizing the intestinal tract of hospitalized patients are the major source of infection as well as nosocomial spread. Despite worldwide increasing rate of multidrug resistant Enterococci colonization and infection among hospitalized patients, there is scarcity of data from resource limited setting. The present study aimed at determining the antimicrobial resistance profile of Enterococcus species from intestinal tracts of hospitalized patients in Jimma, Ethiopia. Methods: The study was conducted among hospitalized patients at Jimma University Specialized Hospital, from January to July 2013. Fecal samples were collected and processed for bacterial isolation and susceptibility testing to antimicrobial agents. Stool samples were inoculated onto enterococcus selective media (Bile Esculin azide agar plate) with and without 6 µg/ml of vancomycin. The isolates were identified to genus and species level by cultural characteristics, Gram’s stain, catalase test, growth in 6.5% NaCl broth, growth at 45°C, motility test and by using API 20 Streptococcus system. Sensitivity testing was done using Kirby–Bauer disk diffusion method. Minimum inhibitory concentrations for vancomycin were determined using E-test strips. Result: Overall, Enterococci were isolated from 114 (76%) of the study subjects. The isolates were Enterococcus faecium (35.1%) followed by Enterococcus faecalis (29.8%), Enterococcus gallinarum (17.5%), Enterococcus casseliflavus (8.8%) and Enterococcus durans (8.8%). Among 114 tested Enterococci isolates, 41 (36%) were resistant to ampicillin, 62 (54.4%) to streptomycin and 39 (34.2%) to gentamycin. Other alternative antibiotics to treat mixed nosocomial infection caused by Enterococci also showed high rate of resistance in vitro: ciprofloxacin (50% of resistance), norfloxacin (49.1%), erythromycin (63.2%), tetracycline (64.9%), chloramphenicol (34.2%), and nitrofrantoin (32.4%). Multiple drug resistance was observed among 89.5% of E. faecium and E. faecalis. Vancomycin resistant Enterococci were observed in 5% of E. faecium isolates. Conclusion: This study reveals high rate of fecal colonization by multidrug-resistant Enterococci and prevalence of vancomycin resistance strains. Thus periodic surveillance of antibacterial susceptibilities is recommended to detect emerging resistance and to prevent the spread of antibacterial-resistant strains.

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Antimicrobial resistance profile of Enterococcus species isolated from intestinal tracts of hospitalized patients in Jimma, Ethiopia

Background: The aim of this study was to determine the occurrence of virulence determinants and vancomycin- resistant genes among Enterococcus faecalis and E. faecium obtained from various clinical sources. Methods: The study was performed on the 280 enterococcal isolated from clinical specimens in Hamadan hospitals, western Iran in 2012-14. Antibiotic susceptibility testing was performed using disk diffusion and Minimal Inhibitory Concentration (MIC) methods. The presence of vancomycin-resistant genes and virulence genes was investigated using PCR. Results: Totally 280 enterococcal isolates were identified as follows: E. faecalis (62.5%) , E. faecium (24%) and Enterococcus spp (13.5%). The results of antibiotic susceptibility testing showed that resistance rates to vancomycin and teicoplanin in E. faecalis and E. faecium isolates were 5% and 73%, respectively. Of Sixty vancomycin-resistant Enterococci strains, fifty-one isolates were identified as E. faecium ( VREfm ) and nine as E. faecalis ( VREfs ). Prevalence of esp, hyl, and asa 1 genes were determined as 82%, 71.6%, and 100%, respectively in E. faecium strains; and 78%, 56/6%, and 97%, respectively in E. faecalis strains. Conclusion: The increased frequency of VREF, as seen with rapid rise in the number of vanA isolates should be considered in infection control practices.

Prevalence of Virulence Factors and Vancomycin-resistant Genes among Enterococcus faecalis and E. faecium Isolated from Clinical Specimens.

Enterococcus is a commensal in the intestine and is now emerging as a drug-resistant pathogen. It produces different virulence factors. Enterococcus surface protein (esp) is a virulence factor that helps in the adhesion, but its role in biofilm formation is still contradictory. Moreover, in many bacterial species, strong biofilm producer exhibits multidrug resistance. Hence, this study is done to know the antimicrobial susceptibility pattern of Enterococcus spp. and to correlate the drug resistance with biofilm production and esp gene. Enterococcal isolates were collected from various clinical specimens. Antibiotic susceptibility testing was done by disc diffusion, and biofilm production was performed by microtiter plate method. PCR was performed for detection of esp gene. Two E. faecium strains resistant to vancomycin and high-level aminoglycoside (HLAR) were non-biofilm-producers and did not harbor esp gene. However, other biofilm-producing E. faecium harbored esp gene, and this association was found to be statistically significant (p=0.024). It was observed that there was no significant association between biofilm formation and presence of esp gene in E. faecalis. Moreover, a significant correlation was not found between drug resistance and biofilm production in both Enterococcus species. Thus, biofilm formation is not always associated with the presence or absence of esp gene and or drug resistance in Enterococcus spp.

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Antibiotic Susceptibility Pattern and Biofilm Formation in Clinical Isolates of Enterococcus spp.

Aims: Enterococcus species are major nosocomial pathogen and are exhibiting vancomycin resistance with increasing frequency.Continouous monitoring and determination of antimicrobial susceptibility pattern is a necessacity.The present study aims to determine the prevalence and susceptibility pattern of Enterococci in tertiary care hospital. Methods and Material: Total of 92 enterococcal strains isolated from various samples were identified and speciated as per scheme of Facklam and Collins. Antibiotic susceptibility was determined for various drugs by Kirby bauer disc diffusion method. Results were interpreted as per CLSI guidelines and were even compared with Vitek2 automated system. Results: 69 strains were E.faecalis, 21 were E.faecium and two were E.gallinarum. High level resistance to penicillin, ampicillin, gentamicin and streptomycin were observed. All strains were sensitive to linezolid and teicoplanin.8% strains showed vancomycin resistance which was detected by Vitek2 automated system. Conclusions: High rate of resistance to penicillin and amino glycosides is observed in our tertiary care hospital and emergence of VRE has further worsened this situation. So, there is an urgent need for more rational and restricted use of antimicrobials.

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Sangita Rewadiwala

Papers

Prevalence of enterococci with higher resistance level in a tertiary care hospital: a matter of concern