Determination of Some Virulence Factors in Staphylococcus aureus , Enterococcus faecalis and Enterococcus faecium Isolated from Meat and Milk Products

2013 ◽  
Vol 33 (4) ◽  
pp. 387-393 ◽  
Author(s):  
Neslihan Gundogan ◽  
Ozlem Ataol ◽  
Fatma Ozturk Torlak
2007 ◽  
Vol 53 (3) ◽  
pp. 372-379 ◽  
Author(s):  
N. Klibi ◽  
K. Ben Slama ◽  
Y. Sáenz ◽  
A. Masmoudi ◽  
S. Zanetti ◽  
...  

Phenotypic and genotypic determination of virulence factors were carried out in 46 high-level gentamicin-resistant (HLGR) clinical Enterococcus faecalis (n = 34) and Enterococcus faecium (n = 12) isolates recovered from different patients in La Rabta Hospital in Tunis, Tunisia, between 2000 and 2003 (all these isolates harboured the aac(6′)–aph(2″) gene). The genes encoding virulence factors (agg, gelE, ace, cylLLS, esp, cpd, and fsrB) were analysed by PCR and sequencing. The production of gelatinase and hemolysin, the adherence to caco-2 and hep-2 cells, and the capacity for biofilm formation were investigated in all 46 HLGR enterococci. The percentages of E. faecalis isolates harbouring virulence genes were as follows: gelE, cpd, and ace (100%); fsrB (62%); agg (56%); cylLLS (41.2%); and esp (26.5%). The only virulence gene detected among the 12 HLGR E. faecium isolates was esp (58%). Gelatinase activity was detected in 22 of the 34 E. faecalis isolates (65%, most of them with the gelE+–fsrB+ genotype); the remaining 12 isolates were gelatinase-negative (with the gelE+–fsrB– genotype and the deletion of a 23.9 kb fragment of the fsr locus). Overall, 64% of the cylLLS-containing E. faecalis isolates showed β-hemolysis. A high proportion of our HLGR E. faecalis isolates, in contrast to E. faecium, showed moderate or strong biofilm formation or adherence to caco-2 and hep-2 cells.


2016 ◽  
Vol 11 (31) ◽  
pp. 113-122
Author(s):  
Carla Franco Porto Belmont Souza ◽  
Luiz Eduardo Souza da Silva Irineu ◽  
Renan Silva De Souza ◽  
Renato da Silva Teixeira ◽  
Ivina Sanches Pereira ◽  
...  

A resistência microbiana tem se mostrado um problema de proporções mundiais, causando estado de morbidade e mortalidade em diversos pacientes. Em vista disso, tem crescido a busca por métodos alternativos naturais de profilaxia. A investigação clínica sugere que o Extrato de Cranberry está entre as melhores propostas de prevenção natural. O Cranberry (Vaccinium macrocarpon) é um fruto que tem crescido comercialmente pelo sabor e propriedades benéficas à saúde. Dentre as formas comercializadas estão: o suco, o chá e as cápsulas contendo o extrato seco. A ação desta planta está relacionada ao tratamento de doenças do trato urinário, por possuir substâncias que inibem a adesão bacteriana ao epitélio do trato urinário, dificultando sua proliferação e reprodução. Dentre todas as infecções relacionadas à assistência a saúde, a Infecção do Trato Urinário é a mais frequentemente associada a procedimentos invasivos. Se não for tratada, pode resultar em complicações como pielonefrite aguda, bacteremia e pionefrose. Portanto, cranberry pode ser uma nova alternativa para o combate das infecções uroepiteliais, por ser um produto natural de preço acessível, e com formas de comercialização diversificada, ao contrário dos antimicrobianos convencionais, que por sua vez são caros e podem acabar causando resistência nos micro-organismos. Este trabalho teve como objetivo avaliar in vitro a atividade antimicrobiana do extrato de Cranberry, adquirido em farmácia de manipulação, sobre 8 micro-organismos isolados de infecções urinárias. As cepas utilizadas, adquiridas da coleção da FIOCRUZ, foram: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Serratia marscecens, Staphylococcus aureus, Enterococcus faecalis e Enterococcus faecium. No estudo, foram utilizados o caldo Mueller Hinton (MH), Extrato de Cranberry e as bactérias patogênicas. O ensaio foi realizado em triplicata, com o uso de um controle de crescimento dos micro-organismos e o experimento para avaliação do crescimento bacteriano na presença do extrato. A turbidez foi medida com o auxílio de um espectrofotômetro, no comprimento de onda de 600 nm, antes e após 24 horas de incubação à 37 ºC. O procedimento forneceu a Densidade Ótica, do qual possibilitou a identificação da inibição microbiana. Para análise estatística foi utilizado o Teste t de Student. O Extrato de Cranberry apresentou atividade antimicrobiana sobre as bactérias Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Serratia marscecens e Enterococcus faecalis (p < 0,05), confirmando seu efeito benéfico em infecções urinárias. No entanto, não teve efeito inibitório significativo sobre Pseudomonas aeruginosa, Proteus mirabilis e Enterococcus faecium (p > 0,05).


2002 ◽  
Vol 46 (6) ◽  
pp. 1845-1850 ◽  
Author(s):  
Kavindra V. Singh ◽  
George M. Weinstock ◽  
Barbara E. Murray

ABSTRACT Enterococcus faecalis isolates are resistant to clindamycin (CLI) and quinupristin-dalfopristin (Q-D), and this is thought to be a species characteristic. Disruption of a gene (abc-23, now designated lsa, for “lincosamide and streptogramin A resistance”) of E. faecalis was associated with a ≥40-fold decrease in MICs of Q-D (to 0.75 μg/ml), CLI (to 0.12 to 0.5 μg/ml), and dalfopristin (DAL) (to 4 to 8 μg/ml) for the wild-type E. faecalis parental strain (Q-D MIC, 32 μg/ml; CLI MIC, 32 to 48 μg/ml; DAL MIC, 512 μg/ml). Complementation of the disruption mutant with lsa on a shuttle plasmid resulted in restoration of the MICs of CLI, Q-D, and DAL to wild-type levels. Under high-stringency conditions, lsa was found in 180 of 180 isolates of E. faecalis but in none of 189 other enterococci. Among 19 erm(B)-lacking Enterococcus faecium strains, 9 (47%) were highly susceptible to CLI (MIC, 0.06 to 0.25 μg/ml) and had DAL MICs of 4 to 16 μg/ml; for the remaining erm(B)-lacking E. faecium strains, the CLI and DAL MICs were 4 to >256 and 2 to >128 μg/ml, respectively. In contrast, none of 32 erm(B)-lacking E. faecalis strains were susceptible (CLI MIC range, 16 to 32 μg/ml; DAL MIC range, ≥32 μg/ml). When lsa was introduced into an E. faecium strain initially susceptible to CLI, the MICs of CLI and DAL increased ≥60-fold and that of Q-D increased 6-fold (to 3 to 6 μg/ml). Introduction of lsa into two DAL-resistant (MICs, >128 μg/ml), Q-D-susceptible (MICs, 0.5 and 1.5 μg/ml) E. faecium strains (CLI MICs, 12 and >256 μg/ml) resulted in an increase in the Q-D MICs from 3- to 10-fold (to 8 and >32 μg/ml), respectively. Although efflux was not studied, the similarity (41 to 64%) of the predicted Lsa protein to ABC proteins such as Vga(A), Vga(B), and Msr(A) of Staphylococcus aureus and YjcA of Lactococcus lactis and the presence of Walker A and B ATP-binding motifs suggest that this resistance may be related to efflux of these antibiotics. In conclusion, lsa appears to be an intrinsic gene of E. faecalis that explains the characteristic resistance of this species to CLI and Q-D.


2001 ◽  
Vol 67 (9) ◽  
pp. 4385-4389 ◽  
Author(s):  
Charles M. A. P. Franz ◽  
Albrecht B. Muscholl-Silberhorn ◽  
Nuha M. K. Yousif ◽  
Marc Vancanneyt ◽  
Jean Swings ◽  
...  

ABSTRACT The incidence of virulence factors among 48 Enterococcus faecium and 47 Enterococcus faecalis strains from foods and their antibiotic susceptibility were investigated. No strain was resistant to all antibiotics, and for some strains, multiple resistances were observed. Of E. faecium strains, 10.4% were positive for one or more virulence determinants, compared to 78.7% of E. faecalis strains. Strains exhibiting virulence traits were not necessarily positive for all traits; thus, the incidence of virulence factors may be considered to be strain specific.


2021 ◽  
Vol 11 (5) ◽  
pp. 278-283
Author(s):  
Betu Rama Soujanya ◽  
Banashankari G S

Introduction: Enterococci from being intestinal commensals have evolved in becoming pathogens and are associated with significant morbidity and mortality Aims & Objectives: This study was done to speciate the uropathogenic Enterococci using the chromogenic medium and to determine the antibiogram also to detect virulence factors phenotypically. Materials and methods: The study included a total of 30 uropathogenic Enterococci isolated over 6 months. Speciation was done using HiCrome Enterococcus faecium agar base. Antibiotic sensitivity was done by the Kirby Bauer Disc Diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Among the virulence factors hemolysin, haemagglutination, and gelatin liquefaction tests were done. Results: Amongst the 30 enterococci isolates, 17 were Enterococcus faecalis (E. faecalis) (56.66%) & 13 were Enterococcus faecium (E. faecium) (43.33 %). 100% of the Enterococcus species were sensitive to Vancomycin & Teicoplanin. 66.67% of the Enterococci showed hemolysis, 10% haemagglutination, and 43.33% gelatinase property. Conclusion: Most common isolated species were Enterococcus faecalis. The changing patterns of antibiotic sensitivity to Enterococci in patients with urinary tract infection possess difficulty in selection of the antibiotics. Failure to synergistic therapy is seen in cases of resistance to High-level Gentamicin. Therefore, speciation and antibiotic sensitivity patterns will help in setting up an empirical therapy and thereby help in the reduction of morbidity and mortality. Key words: Antibiotic susceptibility, Chrome agar, Enterococcus species, virulence factors.


1998 ◽  
Vol 42 (3) ◽  
pp. 721-724 ◽  
Author(s):  
Michael J. Rybak ◽  
Diane M. Cappelletty ◽  
Tabitha Moldovan ◽  
Jeffrey R. Aeschlimann ◽  
Glenn W. Kaatz

ABSTRACT The activities of the oxazolidinone antibacterial agents eperezolid (PNU-100592) and linezolid (PNU-100766) were compared with that of vancomycin against clinical isolates of methicillin-susceptible and -resistant Staphylococcus aureus (n = 200), coagulase-negative staphylococci (n = 100), and vancomycin-susceptible and -resistant Enterococcus faecalisand Enterococcus faecium (n = 50). Eperezolid and linezolid demonstrated good in vitro inhibitory activity, regardless of methicillin susceptibility for staphylococci (MIC at which 90% of the isolates are inhibited [MIC90] range, 1 to 4 μg/ml) or vancomycin susceptibility for enterococci (MIC90 range, 1 to 4 μg/ml). In time-kill studies, eperezolid and linezolid were bacteriostatic in action. A postantibiotic effect of 0.8 ± 0.5 h was demonstrated for both eperezolid and linezolid against S. aureus, S. epidermidis, E. faecalis, and E. faecium.


Author(s):  
Umadevi Sivaraman ◽  
Ravichandran L ◽  
Pramodhini S ◽  
Srirangaraj S ◽  
Seetha Ks

ABSTRACTObjective: To identify some of the virulence factors such as hemolysin, gelatinase, and biofilm production among the clinical isolates of enterococci.Methods: Hemolysin detection using sheep blood agar. Gelatine agar was used for gelatinase production, and tube adherence method was used fordetecting biofilm production.Results: Hemolysin production observed in 49% of isolates, gelatinase production in 41% of isolates, and 46% of isolates were produced biofilm.Conclusion: Virulence factors production was noticed more in Enterococcus faecalis than Enterococcus faecium. It is necessary to find theproduction of important virulence factors among the clinical isolates as they are always associated with virulence of the organism including drugresistance.Keywords: Hemolysin, Gelatinase, Biofilm, Enterococcus.


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