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Background: Enterococci are common commensal organism of enteric tract and act as opportunistic pathogen and may cause infection in community as well as in hospitalised individuals. In present study association of several types of virulence factors like haemolysin, gelatinase and biofilm formation have been studied among HLAR and Vancomycin resistant Enterococci (VRE) isolates of enterococci among UTI patients.Methods: The samples were collected from all hospitalized and OPD patients of MBS Hospital, JK Lone Hospital and NMC Hospital. Government Medical College, Kota, Rajasthan, India. A total of 360 isolates of enterococcus were collected during the period of 2 years from April 2016 to April 2018 in microbiology laboratory, Department of Microbiology, Government Medical College, Kota, Rajasthan, India. All virulence factors were detected by phenotypic methods and MIC values were detected for high level gentamicin and vancomycin.Results: Among all enterococcal isolates most common factor was biofilm production 191 (53.05%) followed by haemolysin 131 (36.38%) and gelatinase production 72 (20%). Total resistant (MIC> 500 µg/ml) isolates for gentamicin was 194 (89.4%). In agar dilution 14 (11.2%) isolates were found sensitive, 61 (48.8%) isolates were found intermediate and 50 (40%) isolates were found to be resistant for vancomycin. HLAR and VRE was maximum associated with haemolysin + bio-film followed by gelatinase+biofilm, haemolysin+gelatinase+bio- film and least with haemolysin + gelatinase.Conclusions: In present study enterococcus show significant production of biofilm and other virulence factors. With production of biofilm they become more resistant to routinely used concentration of antibiotics posing threat for treatment failure. A continuous monitoring is needed particularly for resistance to aminoglycoside and vancomycin to stop their institutional spread. Judicial use of antibiotics should be encouraged both in community as well as in institutions.
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The objective of this study was to investigate the genetic basis of high level aminoglycoside resistance in Acinetobacter baumannii clinical isolates from Beijing, China. 173 A. baumannii clinical isolates from hospitals in Beijing from 2006 to 2009 were first subjected to high level aminoglycoside resistance (HLAR, MIC to gentamicin and amikacin>512 µg/mL) phenotype selection by broth microdilution method. The strains were then subjected to genetic basis analysis by PCR detection of the aminoglycoside modifying enzyme genes (aac(3)-I, aac(3)-IIc, aac(6')-Ib, aac(6')-II, aph(4)-Ia, aph(3')-I, aph(3')-IIb, aph(3')-IIIa, aph(3')-VIa, aph(2″)-Ib, aph(2″)-Ic, aph(2″)-Id, ant(2″)-Ia, ant(3″)-I and ant(4')-Ia) and the 16S rRNA methylase genes (armA, rmtB and rmtC). Correlation analysis between the presence of aminoglycoside resistance gene and HLAR phenotype were performed by SPSS. Totally 102 (58.96%) HLAR isolates were selected. The HLAR rates for year 2006, 2007, 2008 and 2009 were 52.63%, 65.22%, 51.11% and 70.83%, respectively. Five modifying enzyme genes (aac(3)-I, detection rate of 65.69%; aac(6')-Ib, detection rate of 45.10%; aph(3')-I, detection rate of 47.06%; aph(3')-IIb, detection rate of 0.98%; ant(3″)-I, detection rate of 95.10%) and one methylase gene (armA, detection rate of 98.04%) were detected in the 102 A. baumannii with aac(3)-I+aac(6')-Ib+ant(3″)-I+armA (detection rate of 25.49%), aac(3)-I+aph(3')-I+ant(3″)-I+armA (detection rate of 21.57%) and ant(3″)-I+armA (detection rate of 12.75%) being the most prevalent gene profiles. The values of chi-square tests showed correlation of armA, ant(3″)-I, aac(3)-I, aph(3')-I and aac(6')-Ib with HLAR. armA had significant correlation (contingency coefficient 0.685) and good contingency with HLAR (kappa 0.940). The high rates of HLAR may cause a serious problem for combination therapy of aminoglycoside with β-lactams against A. baumannii infections. As armA was reported to be able to cause high level aminoglycoside resistance to most of the clinical important aminoglycosides (gentamicin, amikacin, tobramycin, etc), the function of aminoglycoside modifying enzyme gene(s) in A. baumannii carrying armA deserves further investigation.
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Background & objectives: Enterococci are the leading cause of nosocomial infections, and are thus a persisting clinical problem globally. We undertook this study to determine the virulence factors and the antibiotic resistance in Enterococcus clinical isolates. Methods: One hundred and fifty Enterococcus isolates obtained from various clinical specimens were speciated biochemically and subjected to antibiotic susceptibility testing using Kirby-Bauer disk diffusion method. Resistance to vancomycin was determined by using agar screen method. Haemolysin and gelatinase productions were detected using 5 per cent sheep blood agar and 12 per cent gelatin agar, respectively. Results: Among the 150 Enterococcus isolates, 84 (56%) were E. faecalis. 51(34%) E. faecium, and 15 (10%) were other Enterococcus spp. Haemolysin production was seen among 123 (82%) isolates while 61 (40.6%) isolates produced gelatinase. Nearly 50 per cent of the isolates showed high level aminoglycoside resistance (HLAR). A total of 13 (8.6%) isolates showed vancomycin resistance, of which 11(7.3%) had an MIC >8 μg/ml. Interpretation & conclusions: Presence of VRE was found to be low among the isolates studied. However, occurrence of VRE along with HLAR calls for regular detection of vancomycin resistance promptly and accurately to recognize VRE colonization and infection. Early detection of VRE and HLAR along with their virulence trait will help in preventing the establishment and spread of multidrug resistant Enterococcus species.
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In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6 percent), followed by E. faecium (4.4 percent). The antimicrobial resistance profile was: 2.5 percent to ampicillin, 0.5 percent to vancomycin, 0.5 percent teicoplanin, 33 percent to chloramphenicol, 2 percent to nitrofurantoin, 66.1 percent to erythromycin, 66.5 percent to tetracycline, 24.6 percent to rifampicin, 30 percent to ciprofloxacin and 87.2 percent to quinupristin-dalfopristin. A total of 10.3 percent of the isolates proved to be HLAR to both gentamicin and streptomycin (HLRST/GE), with 23.6 percent resistant only to gentamicin (HLR-GE) and 37.4 percent only to streptomycin (HLRST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital.
Nas últimas duas décadas os membros do gênero Enterococcus emergiram como importantes patógenos nosocomiais ao redor do mundo. No presente estudo, nós avaliamos a resistência antimicrobiana e as características genotípicas de 203 Enterococcus spp. obtidos de diferentes fontes clínicas em dois hospitais de Porto Alegre, Rio Grande do Sul, Brasil. As espécies foram identificadas por testes bioquímicos convencionais e por um sistema automatizado. A diversidade genética de E. faecalis demonstrando resistência à altos níveis de aminoglicosídeos (HLAR) foi avaliada através da análise do DNA cromossômico após digestão com a enzima SmaI, seguido por eletroforese em campo pulsado. O E. faecalis foi a espécie mais freqüente (93,6 por cento), seguido por E. faecium (4,4 por cento). O perfil de resistência antimicrobiana foi: 2,5 por cento para ampicilina, 0,5 por cento para vancomicina, 0,5 por cento para teicoplanina, 33 por cento para cloranfenicol, 2 por cento para nitrofurantoína 66,1 por cento para eritromicina, 66,5 por cento para tetraciclina, 24,6 por cento para rifampicina, 30 por cento para ciprofloxacino e 87,2 por cento para quinupristina-dalfopristina. Um total de 10,3 por cento dos isolados apresentaram HLAR para ambos gentamicina e estreptomicina (HLR-ST/GE), sendo 23,6 por cento resistentes somente a gentamicina (HLR-GE) e 37,4 por cento somente a estreptomicina (HLR-ST). Um grupo clonal predominante foi encontrado em E. faecalis HLR-GE/ST. A prevalência de resistência a antibióticos ²-lactâmicos, e em particular aos glicopeptídeos, foi muito baixa. Entretanto, neste estudo, houve um número crescente de Enterococcus HLAR que podem estar se disseminando intra e interhospitais.
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OBJECTIVE To explore the drug-resistant situation and patients′ basis condition of clinical isolated Enterococcus from Jan to Dec in 2008 to offer evidence for drug-resistant monitoring and clinical antibiotics usage.METHODS All clinical specimens were isolated and cultured and identification conform to Standard′ Operation.The bacteria were identified by using the automatic microorganism analyzer VITEK-2,and bacteria′s drug susceptibility tests were performed using counterparts panel.RESULTS 273 strains Enterococci were isolated,of which E.faecalis were 158 strains,E.faecium were 109 strains,the others were 6 strains.The isolated HLAR E.faecalis were 80 strains and HLAR E.faecium were 10 strains,the isolated.ratio of HLAR was different(P