ABSTRACT
Enterococci have recently become important due to their increased isolation rates in community-based and nosocomial infections and resistance to many antibiotics, including glycopeptides. The aim of this study was to evaluate the antimicrobial susceptible patterns and virulence factors of various clinical specimens; urine (n= 149), blood (n= 38), wound (n= 17), stool (n= 13), and other (n= 12) with a total of 229 enterococci including 138 E.faecalis and 91 E.faecium isolates. Aggregation factor (AF), enterococcus surface protein (esp), cytolysins and gelatinase encoding genes (asa1, esp, cylM, cylBcyl A, cylll, cylls, gelE, respectively) were investigated by molecular methods. Haemolysin production and gelatinase were studied phenotypically. A total of 30 isolates, 29 of E.faecium and one of E.faecalis isolates were resistant to vancomycin. High-level gentamicin and high-level streptomycin resistance in E.faecalis were 40.7% and 63.7% however, they were 47.1% and 55.8% in E.faecalis isolates. All strains were susceptible to linezolid. Ampicillin, penicillin and vancomycin resistance in E.faecium isolates were found to be higher than E.faecalis isolates (p= 0.001, p= 0.008 and p< 0.001). Asa1 (p< 0.001), cylll (p= 0.002) and cylls (p< 0.001) as well as gelatinase activity in isolates of E.faecalis were significantly higher than the isolates of E.faecium (p< 0.001). The most common virulence genes in our study were asa1 gene (45%), cyLs gene (33.2%) and esp gene (32.3%). Ciprofloxacin resistance in cylLL and cyLs gene positive isolates of E.faecalis were significantly higher compared to isolates that do not contain these genes (p= 0.035 and p= 0.047). Likewise, haemolysin producing E.faecium isolates were significantly more resistant to vancomycin compared to isolates that do not produce hemolysin (p< 0.001). When the virulence factors of vancomycin resistant and susceptible isolates were compared, the esp gene level in VRE E.faecium isolates was found to be 24.1%, while no esp gene was found in VRE E.faecalis isolates. The existence of asa1was negative in both VRE E.faecium and VRE E.faecalis isolates. The activity of hemolysin was found 42.3% for E.faecalis and 19.3% for E.faecium. In vancomycin-sensitive enterococcus (VSE) species, esp gene activity was 35.1% for E.faecalis, 29.4% for E.faecium, asa1 gene activity was 60.8% for E.faecalis and 47.1% for E.faecium, hemolysin activity was 52.8% for E.faecalis and 23.5% for E.faecium. In our study, it was found that VSE isolates have more virulence genes than VRE isolates. It should be kept in mind that VRE can causeinfections which are difficult-to-treat especially in hospitalized patients and VSE have significant virulence factors that can cause severe infections.
Subject(s)
Enterococcus faecalis/pathogenicity , Enterococcus faecium/pathogenicity , Gram-Positive Bacterial Infections/microbiology , Virulence Factors/analysis , Anti-Bacterial Agents/pharmacology , Bacteremia/microbiology , Bacteriuria/microbiology , Drug Resistance, Bacterial/genetics , Enterococcus faecalis/drug effects , Enterococcus faecalis/genetics , Enterococcus faecium/drug effects , Enterococcus faecium/genetics , Feces/microbiology , Humans , Vancomycin Resistance/genetics , Virulence Factors/genetics , Wound Infection/microbiologyABSTRACT
Solid organ transplantation is an important therapeutic choice to improve the life quality of patients with end-stage renal disease. Renal transplant recipients have to take immunosuppressive therapy to prevent transplant rejection. However, this treatment increases susceptibility to infection. Bartonella henselae causes systemic, disseminated and silent manifestations in healthy individuals, while the mortality rate is high in immunosuppressive patients in the case of untreated bartonellosis. The diagnosis of B.henselae infections is usually based on serological methods since they are practical, simple and rapid. Recent reports indicated that bartonellosis seen after liver or kidney transplantation have been increased. The aim of this study was to present the antibody seropositivity of B.henselae detected in the serum and plasma samples of renal transplant recipients. This study was aimed to evaluate the antibody seroprevalence in renal transplant recipients and also to compare the antibody results obtained from serum and plasma samples. A total of 59 renal transplant recipients (32 male, 27 female; age range: 20-65 years) followed by Transplantation Unit of Health, Research and Training Center of Pamukkale University, were included in the study. After suspension of lyophilised B.henselae ATCC 49882 (Houston-1); B.henselae co-cultivation to Vero cell culture was performed by the method recommended by Zbinden et al. [Clin Diagn Lab Immunol 1995; 2(6): 693-5]. The cells were taken to co-cultivation in flasks after development of monolayers. In house immunofluorescence antibody (IFA) method was performed with the use of infected cell-coated slides. B.henselae antibodies were studied at 1/64 screening dilution both in serum and plasma samples. In our study B.henselae antibody positivity rates found in serum and plasma samples of the patients were 16.9% (10/59) and 6.8% (4/59), respectively (Cohen κ= 0.37). This detected kappa value indicated that the results of serum and plasma samples revealed "fair agreement". It should be kept in mind that the use of plasma samples in IFA tests would increase the false negative results. Thus the results of this study supported the general approach for the preference of serum samples for serological tests.
Subject(s)
Antibodies, Bacterial/blood , Bartonella Infections/epidemiology , Bartonella henselae/immunology , Kidney Transplantation , Adult , Aged , Bartonella Infections/immunology , Female , Humans , Immunocompromised Host , Male , Middle Aged , Plasma/immunology , Seroepidemiologic Studies , Serum/immunology , Young AdultABSTRACT
The laboratory diagnosis of Bartonella henselae infection is mainly based on serological testing by indirect immunofluorescence assay (IFA). Cell line co-cultivation with B.henselae and agar derivated antigens are the two major procedures used for evaluation of anti-Bartonella antibodies. Vero and Hep-2 cell lines are the most commonly used media for co-cultivation both in-house and commercial diagnostic kits production. However, HeLa cells which are easily supplied and grown, also can easily be infected by B.henselae. The aim of this study was to compare the performances of antigens obtained by co-cultivation of B.henselae ATCC 49882 (Houston-1) in Vero and HeLa Cells in IFA serology. Out of 381 sera samples, 127 (33.3%) were found positive and 195 (51.2%) were found negative by IFA performed by both cell line co-cultivations. The total agreement between the methods were found as 84.5% (322/381), and Cohen kappa value was calculated as 0.68 (strong, coherent). As a result, He-La cells were found to be useful for the preparation of B.henselae antigens to be used in IFA for the serologic diagnosis of B.henselae infections. However different genotype strains and cross reactions with other infectious agents should be investigated by further studies before routine applications of HeLa cell co-cultivations procedure is established.