Nosocomial outbreak of vancomycin-resistant Enterococcus faecium in a paediatric unit at a Turkish university hospital.

BACKGROUND: Despite growing concern about vancomycin-resistant enterococci (VRE) as nosocomial pathogens, especially in the USA, they have been rarely isolated in Turkish hospitals. After initial description in 2001 of unrelated VRE isolates, we report now the molecular characterization of a nosocomial outbreak at the Akdeniz University Hospital, Antalya, Turkey. METHODS: VRE isolates were from either clinical or rectal swab specimens. Identification, susceptibility testing and molecular characterization were performed according to standard techniques. Virulence genes (encoding aggregation substance, gelatinase, cytolysin, enterococcal surface protein and hyaluronidase) were sought by PCR. RESULTS: Thirty-six VRE were isolated from 10 patients between June and October 2005 in the Department of Paediatrics. Six patients were only carriers, two had urinary tract infections and two had bloodstream infections. All isolates were Enterococcus faecium, of vanA genotype and belonged either to a main pulsotype (A) or to three minor pulsotypes (B, C and D). The epidemic strain A, found in eight patients, expressed high-level glycopeptide resistance (MIC of vancomycin 256 mg/L and MIC of teicoplanin 64 mg/L) and was of multilocus sequence typing sequence type (ST) 31, whereas the minor strain D, found in two patients, expressed heterogeneous glycopeptide resistance (MIC of vancomycin 8 to 256 mg/L) and was ST18. Strains B and C were only found in single patients either with strain A or alone. The two epidemic strains A and D were esp gene-positive. Their vanA genes were located on transposons similar to Tn1546, except for deletion of the transposition genes and the presence of IS1542, inserted upstream of the vanA operon, and IS1216, inserted at the 3' end of the vanX gene. VRE outbreak was contained by early identification and implementation of measures for patient isolation and of stringent hand and environmental disinfection policies. CONCLUSIONS: This work underlines the emergence in Turkey of epidemic VRE clones that belong to the clonal complex-17 (CC-17) and that are esp-positive.

Intrapleural streptokinase treatment in children with empyema.

Our aim was to compare intrapleural streptokinase (SK) treatment and simple tube drainage in the treatment of children with complicated parapneumonic pleural effusion. A retrospective review of medical records included patient demographics, clinical presentation, biochemical and microbial studies of pleural effusion, radiographic evaluation of chest tube drainage, use of fibrinolytic agents and type of surgical intervention. During the 2.5-year period (1999-2002), 53 children (29 M, 24 F) with complicated parapneumonic effusions or empyema were identified. Closed tube drainage and antibiotic treatment were administered to patients with a diagnosis of complicated parapneumonic effusion (n = 24) until October 2000; after that time point, intrapleural streptokinase was added to this regimen (n = 29). The median age at the time of presentation was 2.5 years (range: 5 months-14.6 years). There were no significant differences in terms of clinical outcomes between the two groups. The average length of hospital stay was 19.1 +/- 5.5 and 21.9 +/- 11.2 days for the drainage and streptokinase groups, respectively; the time to afebrile state after admission was 5.8 +/- 4.1 and 7.6 +/- 7.5 days. The percentage of patients who eventually required surgical intervention was 8.3% for the drainage group and 20.6% for the streptokinase group. In conclusion, in the treatment of complicated parapneumonic effusions or empyema, the adjunctive treatment with intrapleural SK does not significantly reduce durations of fever, chest tube drainage and hospital stay, and the need for surgery, regardless of the stage of the disease, compared to simple closed tube drainage.

Oleuropein ameliorates arsenic induced oxidative stress in mice.

The objective of this study is to investigate the potential preventive effect of oleuropein in an experimental arsenic toxicity in mice. For this purpose, mice were exposed to 5mg/kg/day sodium arsenite (NaAsO2) in drinking water and treated with 30mg/kg/day oleuropein for 15 days. At the end of the experiment, animals were sacrificed and selected organs were processed for biochemical and histopahtological investigations. Blood, liver, kidney and brain malondialdehyde (MDA) and nitric oxide (NO) levels were determined by colorimetric methods. Protein carbonyl content is measured by a commercial kit. Liver morphology and immunoreactivity for inducible NOS (iNOS) and endothelial NOS (eNOS) was evaluated microscopically. Level of NO was determined to decrease in blood and tissues whereas MDA increased in arsenic given mice. Tissue protein carbonyl content also increased in this group. Immunoreactivity for iNOS and eNOS was noted to increase with arsenic treatment. Oleuropein treatment had significant effects in normalizing the MDA and NO levels as well as protein carbonyl content. Immunohistochemical staining also showed reduction of the expression of iNOS and eNOS in liver. The results indicate that oleuropein ameliorates oxidative tissue damage by scavenging free radicals.

Protective effect of L-carnitine against oxidative damage caused by experimental chronic aflatoxicosis in quail (Coturnix coturnix).

This study was designed to evaluate the effect of L-carnitine supplementation on the plasma malondialdehyde (MDA) and whole blood reduced glutathione (GSH) concentrations in experimentally-induced chronic aflatoxicosis in quails. For this purpose, a total of 80 quails up to 8 weeks old were divided into four equal groups. Group I served as control, Group II was given L-carnitine at the dose of 200 mg/litre in the drinking water for 60 days, Group III was given 60 microg total aflatoxin/kg diet for 60 days, and Group IV was given both 60 microg total aflatoxin/kg diet and 200 mg L-carnitine/litre in the drinking water for 60 days. Aflatoxin treatment caused a significant increase in plasma MDA and a significant decrease in blood GSH concentrations. On the other hand, there was a significant decrease in plasma MDA and a significant increase in whole blood GSH in the L-carnitine-supplemented group. The present study demonstrated that L-carnitine brought about the inhibition of lipid peroxidation by enhancing antioxidant capacity in quails with chronic aflatoxicosis.

Subclinical mastitis causes alterations in nitric oxide, total oxidant and antioxidant capacity in cow milk.

The aim of this study was to investigate total antioxidant (TAC), and oxidant capacity (TOC) and nitric oxide (NO) levels in milk of cows with subclinical mastitis. Brown Swiss and Holstein breed cows were screened with California Mastitis Test (CMT) to determine mammary glands with subclinical mastitis. Moreover, somatic cell counts (SCC) were determined electronically in all milk samples. Mammary quarters were classified as healthy (n=25) or subclinical mastitis (n=35) based on CMT scores and somatic cell count (SCC: < or =200,000/ml or >200,000/ml) in milk. Nitric oxide, TOC and SCC levels were significantly higher (p<0.001, p<0.005 and p<0.001, respectively) in milk from mammary quarters with subclinical mastitis compared to those from healthy mammary quarters. In conclusion, subclinical mastitis results in higher NO concentrations, TOC and SCC, and NO and TOC were positively correlated with SCC. Moreover, alterations in NO levels and TOC in milk could be used as an alternative diagnostic tool to screen for subclinical mastitis.

Naturally occurring MHR variants in Turkish patients infected with hepatitis B virus.

Major B-cell epitopes are located at the major hydrophilic region (MHR) of hepatitis B virus (HBV) surface antigen (HBsAg). The genotypes, subtypes, and naturally occurring amino acid (aa) substitutions of MHR were analyzed in 81 Turkish adult patients (41 inactive HBsAg carriers and 40 patients with chronic hepatitis B) by direct sequencing of the S gene fragment. All the isolates were genotype D according to the phylogenetic analysis. The most common HBsAg subtype was ayw2, followed by ayw3 while one isolate specified ayw4 by encoding Leu127. MHR variants were detected in 22 of the 81 (27.2%) isolates. The prevalence was significantly higher in the chronic hepatitis B group (42.5%) compared to inactive HBsAg carriers (12.2%). Twenty-two samples had a total of 26 amino acid substitutions involving 14 positions. The majority of the patients had a single variation. Most of the amino acid substitutions were located at the HBs1 region of the MHR, while 9 of the 26 were in the classic "a" determinant (aa 124-147). When samples with "a" variants were evaluated by two different commercial HBsAg tests, only the isolate with Ser143Leu variation had a decreased reactivity in the assay using monoclonal antibodies for capture and detection. In conclusion, the findings of the study was in accordance with previous studies showing HBV genotype and subtype homogeneity (genotype D/ayw) in Turkey. Naturally occurring MHR and "a" determinant variants were common, especially among chronic hepatitis B patients. The influence of detected "a" variants on diagnostic assays was limited.

Chromosome-encoded narrow-spectrum Ambler class A beta-lactamase GIL-1 from Citrobacter gillenii.

A novel beta-lactamase gene was cloned from the whole-cell DNA of an enterobacterial Citrobacter gillenii reference strain that displayed a weak narrow-spectrum beta-lactam-resistant phenotype and was expressed in Escherichia coli. It encoded a clavulanic acid-inhibited Ambler class A beta-lactamase, GIL-1, with a pI value of 7.5 and a molecular mass of ca. 29 kDa. GIL-1 had the highest percent amino acid sequence identity with TEM-1 and SHV-1, 77%, and 67%, respectively, and only 46%, 31%, and 32% amino acid sequence identity with CKO-1 (C. koseri), CdiA1 (C. diversus), and SED-1 (C. sedlaki), respectively. The substrate profile of the purified GIL-1 was similar to that of beta-lactamases TEM-1 and SHV-1. The blaGIL-1 gene was chromosomally located, as revealed by I-CeuI experiments, and was constitutively expressed at a low level in C. gillenii. No gene homologous to the regulatory ampR genes of chromosomal class C beta-lactamases was found upstream of the blaGIL-1 gene, which fits the noninducibility of beta-lactamase expression in C. gillenii. Rapid amplification of DNA 5' ends analysis of the promoter region revealed putative promoter sequences that diverge from what has been identified as the consensus sequence in E. coli. The blaGIL-1 gene was part of a 5.5-kb DNA fragment bracketed by a 9-bp duplication and inserted between the d-lactate dehydrogenase gene and the ydbH genes; this DNA fragment was absent in other Citrobacter species. This work further illustrates the heterogeneity of beta-lactamases in Citrobacter spp., which may indicate that the variability of Citrobacter species is greater than expected.