Purpose: Enterococci express high degree of resistance towards wide range of antibiotics. Production of biofilm and many virulence factors along with drug resistance makes it difficult to eradicate the infection from urinary tract. The present study detected the expression of such factors including biofilm production by multidrug-resistant (MDR) enterococci. Materials and Methods: Drug susceptibility of 103 uropathogenic enterococci was performed followed by estimation of minimum inhibitory concentration of high-level gentamicin and vancomycin by microbroth dilution method. Vancomycin-resistant genes were detected by multiplex polymerase chain reaction. Production of virulence factors such as haemagglutination, caseinase, lipase, gelatinase, haemolysin and β-lactamase was detected by phenotypic methods in MDR strains. Biofilm production was detected by calcofluor-white fluorescence staining and semi-quantitative adherence assay. Results: 45% and 18.4% of the isolates were high-level gentamicin-resistant and vancomycin-resistant enterococci (VRE), respectively. vanA gene was detected in 14 and vanB gene in 5 strains. Biofilm, caseinase and gelatinase were the most expressed virulence factor. Expression of caseinase, gelatinase and lipase was significantly higher in Enterococcus faecalis (P < 0.05). Expression of haemagglutination, gelatinase and haemolysin among the vancomycin-resistant isolates was significantly higher (P < 0.05). Conclusion: VanA and vanB are the prevalent genotypes responsible for vancomycin resistance. The high prevalence of MDR enterococcal strains producing biofilm and virulence determinants raises concern. asa1, hyl, esp, gelE, cyl and other genes are known to express these factors and contribute to biofilm formation. Most uropathogenic enterococci expressed biofilm at moderate level and can be detected effectively by calcofluor-white staining. No correlation was noted between vancomycin resistance and biofilm production.


中文翻译：

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印度北部分离的多重耐药尿路致病性肠球菌的生物膜合成和其他毒力因子。



目的：肠球菌对多种抗生素表现出高度耐药性。生物膜和许多毒力因子的产生以及耐药性使得根除尿路感染变得困难。本研究检测了此类因子的表达，包括多重耐药（MDR）肠球菌产生的生物膜。材料与方法：对103株尿路致病性肠球菌进行药敏试验，采用微量肉汤稀释法估算高浓度庆大霉素和万古霉素的最低抑菌浓度。通过多重聚合酶链式反应检测万古霉素耐药基因。通过表型方法检测MDR菌株中血凝酶、酪蛋白酶、脂肪酶、明胶酶、溶血素和β-内酰胺酶等毒力因子的产生。通过钙荧光白荧光染色和半定量粘附测定来检测生物膜的产生。结果：分离株中分别有 45% 和 18.4% 为高水平耐庆大霉素和耐万古霉素肠球菌 (VRE)。 14株检测到vanA基因，5株检测到vanB基因。生物膜、酪蛋白酶和明胶酶是表达最多的毒力因子。粪肠球菌中酪蛋白酶、明胶酶和脂肪酶的表达量显着升高（ P < 0.05）。万古霉素耐药菌株中血凝酶、明胶酶和溶血素的表达显着升高（ P < 0.05）。结论： VanA和vanB是导致万古霉素耐药的常见基因型。产生生物膜和毒力决定因素的耐多药肠球菌菌株的高流行引起了人们的关注。 已知 asa1、hyl、esp、gelE、cyl 和其他基因表达这些因子并有助于生物膜形成。大多数泌尿道致病性肠球菌以中等水平表达生物膜，并且可以通过钙荧光白染色有效地检测到。万古霉素耐药性和生物膜产生之间没有相关性。