[Investigation of Virulence Genes and Carbapenem Resistance Genes in Hypervirulent and Classical Isolates of Klebsiella pneumoniae Isolated from Various Clinical Specimens]. / Çesitli Klinik Örneklerden Izole Edilen Hipervirülan ve Klasik Klebsiella pneumoniae Izolatlarinda Virülans Genleri ve Karbapenem Direnç Genlerinin Arastirilmasi.

Klebsiella pneumoniae is a global pathogen that can cause hospital-acquired and community-acquired infections and is known for its resistance to antibiotics. The pathotype, which is defined as hypervirulent K.pneumoniae (hvKp) is more lethal than classical K.pneumoniae (cKp) isolates and causes many community-acquired infections such as liver abscess, endophthalmitis, pneumonia in healthy young adults. There are no clear clinical or microbiological criteria to define hvKp. String test showing hypermucoviscosity and the iucA gene encoding aerobactin, a siderophore, were used to demonstrate hypervirulence. In this study, it was aimed to investigate the presence of various virulence genes and carbapenem resistance genes in the isolates of K.pneumoniae isolated from various clinical samples in our laboratory and classified as classical and hypervirulent by string test and also to detect the presence of various virulence and carbapenem resistance genes in hvKp isolates. Presence of four virulence genes (fimH-1, rmpA, magA, iucA), K1-K2 serotypes in all isolates and five carbapenem resistance genes (blaOXA-48, blaKPC, blaIMP, blaVIM, blaNDM-1) in carbapenem resistant isolates were investigated with polymerase chain reaction (PCR) method. Forty-five percent of the isolates were defined as hvKp and 55% as cKp. The fimH-1 gene was found to be positive in 94% of the isolates, the iucA gene in 37%, the magA gene (K1) in 34%, the rmpA gene in 5%, and the K2 serotype in 3% of the isolates. iucA gene was positive in 68.9% of hvKp isolates and 10.9% of cKp isolates, and the presence of iucA gene in hvKp isolates was statistically significant compared to cKp isolates (p<0.05). magA gene and K1 serotype were detected in 28.9% of hvKp isolates and 38.2% of cKp isolates. Although the magA gene ratio was high in cKp isolates, this difference was not statistically significant (p> 0.05). fimH-1 gene was found positive in 93.3% of hvKp isolates and 94.5% of cKp isolates. The rmpA gene was positive in 8.9% of hvKp isolates and 1.8% of cKp isolates. The K2 serotype was positive in 4.4% of hvKp isolates and 1.8% of cKp isolates. Although there was no statistical difference in antibiotic susceptibility between hvKp and cKp isolates; ceftriaxone, cefuroxime, ceftazidime, amikacin, cefoxitin, ertapenem, cefuroxime axetil were found to be more sensitive in hvKp isolates. Ciprofloxacin and trimethoprim sulfamethoxazole were found to be more sensitive in hvKp isolates than cKp isolates, and the difference was statistically significant (p<0.05). Although gentamicin, amoxicillin, piperacillintazobactam were not statistically significant in the cKp group, they were more sensitive than the hvKp group (p> 0.05). Carbapenem resistance were found to be 65.7% in cKp and 34.3% in hvKp isolates. Although not statistically significant, hvKp isolates were found to be more sensitive to carbapenems. The most common gene among 35 carbapenem resistant isolates was blaOXA-48 detected in 29 isolates. While the blaKPC gene was detected in five isolates, blaIMP, blaVIM and blaNDM-1 were not detected in any isolates. Sixty nine percent of blaOXA-48 positive samples were found to be in cKp isolates and 31% in hvKp isolates. It was determined that all of the blaKPC positive isolates were hvKp isolates. It was concluded that the string test and virulence factors alone would not be sufficient to show hypervirulence, and that more than one virulence factor combination should be shown in the presence of clinical features of hypervirulent infections to show hypervirulence.

[Evaluation of virulence factors in enterococcus species]. / Enterokok türlerinin virulans faktörlerinin arastirilmasi.

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.

The first report of Brucella suis biovar 1 isolation in human in Turkey.

BACKGROUND: Brucella melitensis and B. abortus are the species generally isolated from human samples in Turkey. Several studies have also demonstrated the presence of antibodies against B. canis. CASE REPORT AND STUDY: Brucella spp. was isolated from blood culture from a 35-year-old male with clinical signs and symptoms of acute meningitis, including fever lasting for 1 week. Multiplex PCR demonstrated B. suis, and biochemical features indicated biovar 1. CONCLUSIONS: This report is the first emphasizing that B. suis should be considered among the causes of brucellosis in Turkey.

The effect of melatonin on bacterial translocation following ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion.

BACKGROUND: Acute mesenteric ischemia is a life-threatening vascular emergency resulting in tissue destruction due to ischemia-reperfusion injury. Melatonin, the primary hormone of the pineal gland, is a powerful scavenger of reactive oxygen species (ROS), including the hydroxyl and peroxyl radicals, as well as singlet oxygen, and nitric oxide. In this study, we aimed to investigate whether melatonin prevents harmful effects of superior mesenteric ischemia-reperfusion on intestinal tissues in rats. METHODS: Rats were randomly divided into three groups, each having 10 animals. In group I, the superior mesenteric artery (SMA) was isolated but not occluded. In group II and group III, the SMA was occluded immediately distal to the aorta for 60 minutes. After that, the clamp was removed and the reperfusion period began. In group III, 30 minutes before the start of reperfusion, 10 mg/kg melatonin was administered intraperitonally. All animals were sacrified 24 hours after reperfusion. Tissue samples were collected to evaluate the I/R-induced intestinal injury and bacterial translocation (BT). RESULTS: There was a statistically significant increase in myeloperoxidase activity, malondialdehyde levels and in the incidence of bacterial translocation in group II, along with a decrease in glutathione levels. These investigated parameters were found to be normalized in melatonin treated animals (group III). CONCLUSION: We conclude that melatonin prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion.

[Investigation of macrolide, lincosamide and streptogramin B resistance in Staphylococcus aureus strains isolated from clinical samples by phenotypical and genotypical methods]. / Klinik örneklerden izole edilen Staphylococcus aureus suslarinda makrolid, linkozamid ve streptogramin B direncinin fenotipik ve genotipik yöntemlerle arastirilmasi

Staphylococcus aureus is one of the most common cause of both community and healthcare-associated infections. As staphylococci have developed resistance to various antibiotics, initially to penicillins then to methicillin and glycopeptides and have the ability to cause epidemics, they continue to be a major problem from past to present. Methicillin resistance gave rise to the use of alternative antibiotics such as macrolides, however worldwide development of macrolide resistance limited the use of these antibiotics. Macrolide resistance occurs either through target site modification (MLS(B) phenotype, encoded by erm genes), efflux pumps (MS phenotype, encoded by msrA/B genes) or decreased cell wall permeability. The aim of this study was to investigate the MLS(B) resistance of clinical S.aureus strains with phenotypic and genotypic methods. A total of 404 S.aureus strains isolated from different clinical samples (50% wound, 15% tracheal aspirate and 35% other samples) of inpatients (93.3%) and outpatients (6.7%) were included in the study. Double disc synergy test (D-test) was used for the phenotypical research and PCR was used for the genotypical research of MLS(B) resistance of isolates. One hundred fifty eight (39.1%) of the S.aureus isolates were methicillin-resistant (MRSA), and 246 (60.9%) were methicillin-susceptible (MSSA). By the use of D-test, constitutive (cMLS(B)) and inducible (iMLS(B)) clindamycin resistance were detected in 19 and 111 isolates, respectively, while five isolates were MS phenotype and 268 isolates were S phenotype (susceptible to erythromycin and clindamycin). The resistance genes of 136 isolates with MLS(B) resistance phenotype were determined genotypically and among 111 isolates showing iMLS(B) phenotype ermA gene was found in 81.9% (83 MRSA, 8 MSSA), ermC gene in 10.8% (7 MRSA, 5 MSSA), msrA gene in 10.8% (11 MRSA, 1 MSSA), msrB gene in 1.8% (2 MRSA) and ermB gene in 0.9% (1 MRSA). Among 19 strains with cMLS(B) phenotype, ermA was found in 57.9% (10 MRSA, 1 MSSA), ermC in 36.8% (6 MRSA, 1 MSSA) and ermB in 15.8% (3 MRSA). Among five strains with MS phenotype, ermA was found in 80% (2 MRSA, 2 MSSA), msrA in 75% (3 MSSA), msrB in 50% (2 MSSA) and ermC in 25% (1 MSSA) of the isolates. ErmA and ermC genes were detected together in 14 isolates, ermA, ermC and msrA genes in one isolate, ermA and msrA genes in 11 isolates, ermA, msrA and msrB genes in three isolates and ermA and ermB genes in three isolates, respectively. In this study, two MRSA isolates with MS phenotype and negative D-test had only ermA gene and among two MSSA strains, erm genes were also determined in addition to msr genes. In our study RAPD-PCR method was used to investigate the clonal similarity, however no dominance of one or a number of clonal type was observed among the isolates in which the resistance genes were identified. In conclusion, the detection of MLS(B) resistance in S.aureus isolates is likely to influence the selection of antibiotics in the treatment of the infections caused by this bacteria.

The investigation of the possible relationship between Coxsackie viruses and pemphigus.

BACKGROUND: Pemphigus is a group of autoimmune bullous diseases on which the etiopathogenesis of several viruses has been blamed. Coxsackie viruses (CVs) are the causative agents of hand, foot, and mouth disease, and herpangina, which have been strongly associated with several autoimmune diseases. The onset of pemphigus after CV infection and cephalosporin use has been reported. OBJECTIVE: To detect the presence of CV in patients with pemphigus. MATERIALS AND METHODS: Reverse transcriptase-polymerase chain reaction analysis for CV RNA sequences and immunohistochemical staining for the CV and adenovirus receptor expression were performed on patient skin samples. CV-IgM and -IgG serum levels were analyzed. RESULTS: Thirty-two patients and 40 controls were investigated. Neither the CV and adenovirus receptor expression nor CV RNA sequences was established in the skin samples of patients. The ratio of CV-IgG positivity was higher in patients (12.5%) than in the controls (5%; P > 0.05). CONCLUSION: Our preliminary results indicate that the viral genome of CV does not become persistent in the skin. Further studies with a larger number of cases are needed to clarify the place of CVs in the etiopathogenesis of pemphigus.

Seroprevalence of hepatitis e virus among primary school children.

OBJECTIVES: To investigate the seroprevalence of anti-hepatitis E virus antibody among primary school children in the two different areas of Denizli, Turkey. Methodology : Anti-HEV antibodies were investigated in 185 primary school children (91 from rural areas and 94 from urban areas of Denizli). The children were divided into two age groups as seven-year old group and fourteen-year old group. Samples were tested for anti-HEV Ab by an enzyme-linked immunoassay. Results : A total of 23 primary school children were anti-HEV Ab positive, giving a prevalence of 12.4%. The seroprevalence rate was 13.1% in rural areas and 11.7% in urban areas. The difference in the seropositive rates was not statistically significant (p>0.05). Among 185 primary school children, Anti-HEV antibodies were positive 17 (18.1%) in seven-year old group, and 6 (6.6%) in fourteen-year old group. The difference in the seropositive rates was statistically significant (p<0.05). Conclusions : There was no association between the anti-HEV Ab and gender, socioeconomic level, parental educational level, rural or urban areas. Anti-HEV Ab seroprevalence was higher in seven-year old children than fourteen-year old children.

[Prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization among outpatients undergoing hemodialysis treatment]. / Ayaktan Hemodiyaliz Tedavisi Alan Hastalarda Nazal Metisiline Dirençli Staphylococcus aureus Kolonizasyon Prevalansi ve Risk Faktörleri.

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) is frequent among hemodialysis patients and lead to increased morbidity and mortality rates. It is known that nasal colonization plays an important role for the development of MRSA infections. The aim of this study was to determine the prevalence and risk factors for MRSA colonization among outpatients undergoing hemodialysis. A total of 466 adult patients (199 female, 267 male; age range: 18-89 years, mean age: 55.8 ± 15.1 years) who were under hemodialysis between September-December 2008 in different health centers at Pamukkale/ Denizli region, Turkey, were included in the study. Swab samples obtained from anterior nares of patients were cultivated on sheep-blood agar and mannitol-salt agar media. The isolates were identified by conventional bacteriological methods. S.aureus strains were isolated from 204 (43.8%) patients and 34 (16.7%) were found methicillin-resistant. Thus the rate of MRSA colonization in hemodialysis patients was detected as 7.3% (34/466). All of the MRSA strains were found susceptible to vancomycin, linezolid and tigecycline, while the resistance rates for the other antimicrobial agents were as follows: 70.6% to azithromycin and claritromycin; 64.7% to erythromycin; %58.8 to clindamycin, gentamicin and trimethoprim-sulfamethoxazole; 55.9% to ciprofloxacin; 44.1% to tetracycline and rifampin; 5.9% to chloramphenicol. Inducible clindamycin resistance in MRSA isolates was %23.5 (8/34), and multidrug resistance rate was 76.5% (26/34). Multivariate analysis revealed that the history of previous hospitalization within a year [odds ratio (OR), 3.426; 95% confidence interval (CI), 1.595-7.361, p= 0.002] and the presence of chronic obstructive lung disease (OR, 5.181; 95% CI, 1.612-16.648, p= 0.006) were independent risk factors for MRSA colonization in this population. A better understanding of the prevalence and risk factors for nasal MRSA colonization among hemodialysis population may hold significant implications for both the treatment strategies and prevention of MRSA infections to establish appropriate infection control measures.

Prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization in a diabetic outpatient population: a prospective cohort study.

BACKGROUND: Diabetes mellitus is a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection. We attempted to determine the prevalence and risk factors for MRSA colonization in a population of outpatients with diabetes. METHODS: This prospective cohort study enrolled patients with diabetes. Anterior nares cultures were obtained from patients with diabetes admitted to outpatient endocrinology and metabolism clinics, and risk factors for MRSA colonization were analyzed. RESULTS: Out of the 304 patients evaluated, 127 (41.9%) were colonized with S aureus and 30 (9.9%) were colonized with MRSA. Overall, 23.6% of all S aureus isolates were MRSA. In multivariate analysis, factors independently associated with an increased risk of MRSA colonization included the presence of connective tissue disease (odds ratio, 7.075; 95% confidence interval, 2.157-23.209; P = .001) and insulin therapy (odds ratio, 3.910; 95% confidence interval, 1.652-9.251; P = .002). CONCLUSIONS: The prevalence of MRSA colonization in our sample of diabetic outpatients was 9.9%. Independent risk factors for MRSA colonization were the presence of connective tissue disease and insulin use. A better understanding of the epidemiology and risk factors for nasal MRSA colonization in the persons with diabetes may have significant implications for the treatment and prevention of MRSA infections.

Comparison of antimicrobial agents as therapy for experimental endocarditis: caused by methicillin-resistant Staphylococcus aureus.

We used an experimental rat model to compare the therapeutic efficacy of teicoplanin, linezolid, and quinupristin/dalfopristin with that of vancomycin as standard therapy for infective endocarditis.Aortic endocarditis was induced in rats by insertion of a polyethylene catheter into the left ventricle, followed by intravenous inoculation of 106 colony-forming units of methicillin-resistant Staphylococcus aureus 24 hours later. Forty-eight hours after bacterial challenge, intravenous antibiotic therapies were initiated. There were 6 groups of 8 rats each: uninfected control; infected, untreated control; vancomycin-treated (40 mg/kg twice daily); teicoplanin-treated (20 mg/kg twice daily after a loading dose of 40 mg/kg); linezolid-treated (75 mg/kg 3 times daily for 1 day, then 75 mg/kg twice daily); and quinupristin/dalfopristin-treated (30 mg/kg twice daily and an additional 10 mg/kg dalfopristin infusion over 6 to 12 hr daily). At the end of therapy, the aortic valve vegetations in the drug-treated rats were evaluated microbiologically.Compared with the infected, untreated group, all drug-treated groups had significantly reduced bacterial titers in the vegetations. Vancomycin, teicoplanin, and quinupristin/dalfopristin all effectively reduced the quantitative bacterial cultures of aortic valve vegetations. In addition, there was no significant difference in the comparative efficacy of teicoplanin, linezolid, and quinupristin/dalfopristin. Vancomycin significantly reduced bacterial counts in comparison with linezolid, which was nonetheless also effective.Our experimental model showed that each of the investigated antimicrobial agents was effective in the treatment of infective endocarditis.

Tempol reduces bacterial translocation after ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion.

PURPOSE: We investigated whether Tempol, a water-soluble antioxidant, prevents the harmful effects of superior mesenteric ischemia/reperfusion on intestinal tissues in rats. METHODS: The rats were divided into three groups of 10. In group 1, the superior mesenteric artery (SMA) was isolated but not occluded, and in groups 2 and 3 the superior mesenteric artery was occluded for 60 min. After that, the clamp was removed and reperfusion began. In group 3, 5 min before the start of reperfusion, a bolus dose of 30 mg/kg Tempol was administered intravenously and continued at a dose of 30 mg/kg for 60 min. All animals were euthanized after 24 h and tissue samples were collected for analysis. RESULTS: There was a significant increase in myeloperoxidase activity, malondialdehyde levels, and the incidence of bacterial translocation in group 2, with a decrease in glutathione levels. These parameters were found to be normalized in group 3. The intestinal mucosal injury score in group 2 was significantly higher than those in groups 1 and 3. CONCLUSION: Tempol prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion.

Comparison of the therapeutic efficacy of linezolid and vancomycin and correlation of serum and tissue malondialdehyde and myeloperoxidase in an experimental mediastinitis model.

BACKGROUND: We aimed to investigate the therapeutic efficacy of linezolid in an experimental mediastinitis model and to compare it with vancomycin, which is commonly used. The objective of this study was also to evaluate the role of the immune system in mediastinitis. MATERIALS AND METHODS: Fifty adult Wistar rats were randomly divided into five groups: an uncontaminated and contaminated untreated control groups; a group that received sefazolin prophylaxis; and two groups treated with vancomycin or linezolid. Median sternotomy without access to pleural spaces was performed on all rats. All groups, except the uncontaminated one, were inoculated with 0.5 mL 10(8) colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Postoperatively, vancomycin and linezolid groups were given antibiotic treatment for 7 d, starting 24 h after the end of the procedure. After 7-d treatment tissue samples from the upper ends of the sternotomy line and mediastinum were obtained and evaluated microbiologically. Additionally, serum, heart, lung, liver, kidney, and mediastinal tissues samples were obtained to determine malondialdehyde (MDA) and myeloperoxidase (MPO). RESULTS: The study showed that either vancomycin or linezolid successfully reduced bacterial counts in mediastinum and sternotomy line. MDA and MPO levels were found to be decreased in the treated groups. There was a positive correlation between serum and tissues MDA and MPO in all of the groups. CONCLUSIONS: Our study showed that linezolid appears to be a promising option for treating mediastinitis due to methicillin-resistant S. aureus. Additionally, it was demonstrated that a wide inflammatory process occurred after mediastinitis.

[Investigation of CTX-M type beta-lactamases in Klebsiella pneumoniae clinical isolates by phenotypic and molecular methods]. / Klebsiella pneumoniae klinik izolatlarinda CTX-M tipi beta-laktamazlarin fenotipik ve moleküler yöntemlerle arastirilmasi.

Rapid spread of CTX-M type extended-spectrum beta-lactamases (ESBL) between the members of Enterobacteriaceae receives attention increasingly all throughout the world. The aim of this study was to investigate the presence of CTX-M type ESBL in Klebsiella pneumoniae clinical strains by phenotypic and molecular methods. A total of 217 non-repetitive K. pneumoniae strains isolated from clinical specimens (152 urine, 20 sputum, 17 wound swabs, 13 blood, 9 tracheal aspirate, 3 CSF and 3 conjunctival swab samples) of inpatients (n = 128) and outpatients (n = 89) admitted to Pamukkale University Medical Faculty Hospital, between January 2006-January 2007, were included to the study. In vitro antimicrobial susceptibilities were determined by disk diffusion technique in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines, and CT (cefotaxime)/CTL (cefotaxime-clavulanate) containing Etest strips (AB Biodisk, Sweden) were applied for phenotypic detection of cefotaximase production. PCR was performed for the detection of CTX-M genes and the subgroups, while the clonal relatedness of the CTX-M positive isolates was investigated by random amplified polymorphic DNA (RAPD) analysis. While imipenem resistance was not detected in any of the isolates, highest rates of resistance were detected for ampicillin (94%) and cephalothin (64.5%) in 217 K. pneumoniae strains. Using the E-test 39.6% (86/217) of the isolates were found positive, and CTX-M positivity was significantly higher in the strains isolated from inpatients (87.4%) than outpatients (12.6%) (p < 0.001). CTX-M gene was identified in 22.1% (19/86) of the E-test positive isolates. All of the CTX-M positive isolates were identified as CTX-M group-1. The highest resistance rates of CTX-M-1 strains were detected for amoxycillin-clavulanate (94.7%) and netilmicin (89.5%), while the lowest rates were detected for ciprofloxacin (26.3%), trimethoprim/sulphamethoxazole (26.3%) and amikacin (42.1%). RAPD identified 11 different banding patterns among the 19 CTX-M-1 positive isolates, the most frequent clusters being Kp3 (n = 3), Kp4 (n = 3) and Kp5 (n = 3). Five of the 8 isolates from pediatric intensive care unit and 4 of the 5 isolates from other pediatric wards exhibited the same band pattern indicating a possible clonal dissemination. Continuous surveillance of beta-lactamases and the identification of their types in gram-negative enteric bacteria has important clinical impact, since it can often provide valuable information for effective infection control measures and for the choice of appropriate antimicrobial therapy.

[Investigation of siderophore, total matrix protease and elastase activity in Pseudomonas aeruginosa isolates from lower respiratory tract and extra-respiratory tract samples]. / Alt solunum yolu örnekleri ve solunum yolu disi örneklerden izole edilen Pseudomonas aeruginosa suslarinda siderofor, total matriks proteaz ve elastaz aktivitesinin arastirilmasi.

Pseudomonas aeruginosa is an important opportunistic pathogen. P. aeruginosa strains secrete several virulence factors, in the form of extracellular proteins. Adhesins, pyocyanin, proteases, hemolysins, exotoxin A and exoenzyme S are some of the virulence factors found in P. aeruginosa strains. In this study, the presence of siderophore, total matrix protease and elastase activities were investigated in a total of 157 P. aeruginosa strains isolated from lower respiratory tract (n: 81; sputum, bronchoalveolar lavage, tracheal aspirate) and extrarespiratory sites (n: 76; urine, wound, blood) of hospitalized pati ents. Chrome azurol S (CAS) agar plates were used for detection of siderophore activity. Hide powder azure was used for the investigation of total matrix protease activity and elastin congo red was used to test elastase activity. All strains gave positive reaction on CAS agar. Enzyme activities of the test strains were compared with the activity of P. aeruginosa PAO1 positive control strain. Mean total matrix protease and elastase activities were less than P. aeruginosa PAO1 activity in the test strains, however, some strains exhibited activity higher than PAO1. There was no significant difference for mean protease and elastase activities between the strains isolated from lower respiratory tract samples and the others (p > 0.05) [corrected] as well as no difference with respect to antibiotic resistance (p > 0.05) [corrected] It was found that ceftazidime and cefoperazone were the most resistant agents in both groups (67.9% and 57.9% for ceftazidime and 49.3% and 48.7% for cefoperazone, respectively). It was concluded that further in vivo studies are necessary to clarify the role of virulence factors of P. aeruginosa in the establishment of infection in different body sites.

[Successful treatment of a patient with multidrug resistant Acinetobacter baumannii meningitis with high dose ampicillin-sulbactam]. / Coklu ilaç dirençli Acinetobacter baumannii menenjiti olgusunun yüksek doz ampisilin-sülbaktam ile basarili tedavisi.

Acinetobacter baumannii is an important pathogen which causes severe nosocomial infections such as meningitis. Multidrug resistance is a growing problem throughout the world. In this report a case of multidrug resistant A.baumannii meningitis, treated with high dose of ampicillin-sulbactam (SAM) was presented. Rhinorrhea and confusion developed on the postoperative seventh day in a 67 years old male patient operated for macroadenoma of the hyphophysis gland. Since the cerebrospinal fluid (CSF) findings indicated a central nervous system infection, nosocomial meningitis was diagnosed and intravenous ceftazidime and vancomycin have started. Blood and CSF cultures of the patient revealed no growth and his general condition has improved. However, fever and confusion emerged again on the 21st day of therapy and the repeat CSF sample revealed increased pressure, purulent appearance, 510/mm3 leukocytes (90% PMNL), 58 mg/dl glucose (simultaneous blood glucose was 144 mg/dl) and 49 mg/dl protein. Direct microscopic examination of CSF revealed gram-negative coccobacilli and A.baumannii was identified in the culture. The isolate was resistant to piperacillin-tazobactam, third generation cephalosporins, aztreonam, ciprofloxacin, carbapenems and aminoglycosides, susceptible to sulbactam ampicillin and colistin. Ampicillin (12 gr) and sulbactam (6 gr) treatment was initiated and at the 72nd hour of the therapy the temperature and conciousness level of the patient returned to normal. Control CSF sample obtained on the 14th day of treatment revealed no leukocytes and no bacterial growth. The treatment was continued for 21 days and the patient recovered without any sequela. Since colistin which is one of the alternative antimicrobial treatment choices for resistant Acinetobacter infections, is not found in Turkey, sulbactam-ampicillin might be an effective and safe choice for the treatment of multi-resistant A. baumannii meningitis if the isolate was proven to be susceptible by antibiotic susceptibility tests.

Community-acquired Streptococcus mitis meningitis: a case report.

BACKGROUND: Streptococcus mitis is prevalent in the normal flora of the oropharynx, the female genital tract, gastrointestinal tract, and skin. Although it is usually considered to have low virulence and pathogenicity, Streptococcus mitis may cause life-threatening infections, particularly endocarditis. Meningitis with S. mitis is rare, but has been described in individuals with previous spinal anesthesia, neurosurgical procedure, malignancy, or neurological complications of endocarditis. CASE REPORT: A 58-year-old, alcoholic male patient with a high fever, headache, and changes in mental status was admitted to hospital with the diagnosis of meningitis. S. mitis, isolated from cerebrospinal fluid, was sensitive to penicillin. He was given a 14-day course of ampicillin and made a full clinical recovery. CONCLUSIONS: The purpose of this report is to emphasize the importance of the occurrence of S. mitis meningitis in patients with concomitant factors such as older age (>50 years), alcoholism, poor oral hygiene, and maxillary sinusitis.

Evaluation of biofilm production, gelatinase activity, and mannose-resistant hemagglutination in Acinetobacter baumannii strains.

BACKGROUND AND PURPOSE: Acinetobacter baumannii is an important nosocomial pathogen, but its pathogenic characteristics are not well defined. The purpose of this study was to evaluate biofilm production, mannose-resistant hemagglutination, and gelatinase production in A. baumannii strains isolated from various clinical specimens. METHODS: Eighty six strains of A. baumannii isolated from 86 hospital inpatients were studied for biofilm formation, gelatinase activity, and mannose-resistant hemagglutination. The isolates were identified using conventional techniques and/or the API 2ONE system. Comparisons of biofilm production, gelatinase activity, and mannose-resistant hemagglutination were made by chi-squared analysis. RESULTS: Twenty two and 61 of the isolates agglutinated human group O and AB erythrocytes in the presence of mannose, respectively. Gelatinase activity was detected in 12 isolates (14%), while 64 isolates formed biofilms. CONCLUSIONS: Several parameters may play important roles in causing infection in colonized patients. Identifying the factors that influence virulence may help to separate the colonizing strains into those with high or low potential virulence.

[Investigation of hepatitis G virus prevalence in hemodialysis patients and blood donors in Denizli, Turkey]. / Denizli'de hemodiyaliz hastalarinda ve kan donörlerinde hepatit G virus prevalansinin arastirilmasi.

This study focuses on the prevalence of hepatitis G virus (GBV-C/HGV) in hemodialysis patients and blood donors in Denizli (located at Aegean region of Turkey). A total of 100 patients (mean age: 56.8 +/- 13.3 years; 46 female) receiving hemodialysis and 100 blood donors (mean age: 31.3 +/- 8.1 years; 8 female) were included in the study. The presence of GBV-C/HGV RNA was determined in all patients by reverse transcriptase-PCR and the presence of GBV-C/HGV anti-E2 antibodies was determined by a commercial enzyme immunoassay (Diagnostic Automation, INC). Viral RNA positivity was determined in 14 (14%) of the hemodialysis patients and 2 (2%) of the blood donors, the difference being statistically significant (p < 0.05). GBV-C/HGV anti-E2 antibodies were detected in 1 (1%) of the hemodialysis patients and 3 (3%) of the blood donors. Anti-E2 positive patient also revealed positive result for viral RNA. There was no statistically significant difference between the two groups in terms of anti-E2 positivity. The prevalence of GBV-C/HGV was 14% in hemodialysis patients and 5% in blood donors (p < 0.05). There was no significant difference in terms of duration of hemodialysis, serum ALT levels, age or gender between GBV-C/HGV positive and negative hemodialysis patients. In conclusion, since hemodialysis patients are at an increased risk of parenteral transmission, they have significantly higher GBV-C/HGV viremia rates and prevalence when compared to blood donors. However, the prevalence of GBV-C/HGV and coexistence between GBV-C/HGV and hepatitis C virus have been decreasing in our region owing to increased hygienic precautions in hemodialysis units, avoidance of unnecessary blood transfusions and more widespread use of erythropoietin.

Efficacy of linezolid in the treatment of mediastinitis due to methicillin-resistant Staphylococcus aureus: an experimental study.

INTRODUCTION: The treatment of postoperative mediastinitis is very important because of its high morbidity, mortality, and increased hospital stay and hospital costs. The aims of our research were to investigate whether linezolid alone can be an effective treatment agent for methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis, and to determine whether linezolid can provide synergistic activity when given in combination with rifampin. METHODS: A partial upper median sternotomy was performed on 70 rats. The animals were divided into seven groups: an uncontaminated control group; an untreated contaminated group; three contaminated groups that received antibiotic therapy with either 25 or 50 mg/kg linezolid twice a day, or rifampin 5 mg/kg twice a day; and two contaminated groups that received a combination therapy consisting of 25 or 50 mg/kg linezolid and rifampin 5 mg/kg twice a day. The antibiotic treatment lasted 7 days. Tissue samples from the upper ends of the sternum and swab specimens of the upper mediastinum were obtained and evaluated microbiologically. RESULTS: The 25-mg/kg dose of linezolid, either alone or combined with rifampin, was not effective in reducing the bacterial counts in mediastinum and sternum. Quantitative bacterial cultures of mediastinum and sternum were significantly lower in the groups receiving 50 mg/kg linezolid alone or in combination with rifampin compared with the control. Adding of rifampin to linezolid therapy did not result in a significant change in bacterial counts versus linezolid alone. CONCLUSION: A high dose of linezolid should be considered as a possible therapeutic agent for the treatment of post-sternotomy infection caused by MRSA.