Investigation of Staphylococcus strains with heterogeneous resistance to glycopeptides in a Turkish university hospital

BACKGROUND: The hetero-glycopeptide intermediate staphylococci is considered to be the precursor of glycopeptide intermediate staphylococci especially vancomycin intermediate Staphylococcus aureus (VISA). For this purpose, we aimed to investigate the heterogeneous resistance to glycopeptide and their frequencies in 135 Staphylococcus strains. METHODS: Heterogeneous resistance of Staphylococcus strains was detected by inoculating the strains onto Brain Heart Infusion agar supplemented with 4 mg/L of vancomycin (BHA-V4). Agar dilution method was used for determining MICs of glycopeptides and population analysis profile was performed for detecting frequency of heterogeneous resistance for the parents of selected strains on BHA-4. RESULTS: Eight (6%) out of 135 Staphylococcus strains were exhibited heterogeneous resistance to at least one glycopeptide. One (1.2%) out of 81 S. aureus was found intermediate resistance to teicoplanin (MIC 16 mg/L). Other seven strains were Staphylococcus haemolyticus (13%) out of 54 coagulase negative staphylococci (CoNS). Six of the seven strains were detected heterogeneously reducing susceptibility to vancomycin (MICs ranged between 5–8 mg/L) and teicoplanin (MICs ranged between 32–64 mg/L), and one S. haemolyticus was found heterogeneous resistance to teicoplanin (MIC 32 mg/L). Frequencies of heterogeneous resistance were measured being one in 10(6 )– 10(7 )cfu/ml. MICs of vancomycin and teicoplanin for hetero-staphylococci were determined as 2–6 folds and 3–16 folds higher than their parents, respectively. These strains were isolated from six patients (7%) and two (4%) of health care wokers hands. Hetero-VISA strain was not detected. CONCLUSION: Heterogeneous resistance to glycopeptide in CoNS strains was observed to be significantly more emergent than those of S. aureus strains (vancomycin P 0.001, teicoplanin, P 0.007). The increase MICs of glycopeptide resistance for subpopulations of staphylococci comparing with their parents could be an important clue for recognizing the early steps in the appearance of VISA strains. We suggested to screen clinical S. aureus and CoNS strains, systematically, for the presence of heterogeneously resistance to glycopeptide

Characterization of coagulase-negative staphylococcal isolates from blood with reduced susceptibility to glycopeptides and therapeutic options

<p>Abstract</p> <p>Background</p> <p>Coagulase-negative staphylococci (CoNS) are a major cause of nosocomial blood stream infection, especially in critically ill and haematology patients. CoNS are usually multidrug-resistant and glycopeptide antibiotics have been to date considered the drugs of choice for treatment. The aim of this study was to characterize CoNS with reduced susceptibility to glycopeptides causing blood stream infection (BSI) in critically ill and haematology patients at the University Hospital Tor Vergata, Rome, Italy, in 2007.</p> <p>Methods</p> <p>Hospital microbiology records for transplant haematology and ICU were reviewed to identify CoNS with elevated MICs for glycopeptides, and isolates were matched to clinical records to determine whether the isolates caused a BSI. The isolates were tested for susceptibility to new drugs daptomicin and tigecycline and the genetic relationship was assessed using f-AFLP.</p> <p>Results</p> <p>Of a total of 17,418 blood cultures, 1,609 were positive for CoNS and of these, 87 (5.4%) displayed reduced susceptibility to glycopeptides. Clinical review revealed that in 13 cases (7 in haematology and 6 in ICU), CoNS with reduced susceptibility to glycopeptides were responsible for a BSI. <it>Staphylococcus epidermidis </it>was the causative organism in 11 instances and <it>Staphylococcus haemolyticus </it>in 2. The incidence of oxacillin resistance was high (77%), although all isolates remained susceptible to linezolid, daptomycin and tigecycline. Fingerprinting of CoNS identified one clonal relationship between two isolates.</p> <p>Conclusion</p> <p>Multi-resistant CoNS with reduced susceptibility to glycopeptides, although still relatively infrequent in our hospital, are emerging pathogens of clinical concern. Surveillance by antibiotyping with attention to multi-resistant profile, and warning to clinicians, is necessary.</p

Investigation of Staphylococcus strains with heterogeneous resistance to glycopeptides in a Turkish university hospital

Background: The hetero-glycopeptide intermediate staphylococci is considered to be the precursor of glycopeptide intermediate staphylococci especially vancomycin intermediate Staphylococcus aureus (VISA). For this purpose, we aimed to investigate the heterogeneous resistance to glycopeptide and their frequencies in 135 Staphylococcus strains

Heterotrophic bacteria and filamentous fungi isolated from a hospital water distribution system

In recent years, hospital infections caused by opportunist micro-organisms in immunosupressed patients groups have become increasingly important. These micro-organisms grow easily in water distribution systems even to the extent of producing bio-film. In the present study the aim was to determine microbial populations in water samples collected from the distribution system of a big hospital. Water samples were collected from one hundred different points around the water distribution system in different sections of the hospital. To analyse the water a membrane filter method was used. In eighty-four samples heterotrophic bacteria were isolated. The most frequent bacteria determined were Bacillus spp. (77%), Bacillus cereus (11%), Pseudomonas spp. (5%) and Staphylococcus spp. (4%). In fifteen samples more than one species of bacteria were isolated. In fifty-one samples, sixteen species of fungi were isolated, the most frequent being Penicillium spp. (24%), Aspergillus spp. (8%) and Acremonium spp. (5%). In thirteen samples more than one type of fungi was determined. In only six samples was no growth of fungi or bacteria observed. Over all the one hundred samples the counts of heterotrophic bacteria were not significantly correlated with the filamentous fungi counts (rs = -012, p = 0.05). Differences in the level of isolation or the concentration of bacteria and fungi between water from three old buildings and water from four new buildings were not significant (p > 0.05)

Handwashing frequencies in an intensive care unit

As most nosocomial infections are thought to be transmitted by the hands of healthcare workers, handwashing is considered the single most important intervention to prevent nosocomial infections. However, previous studies have shown that handwashing practices are poor, especially among medical personnel. The objective of this study was to assess the rate of handwashing among intensive care unit (ICU) healthcare personnel, and then to propose realistic suggestions so that `hand hygiene&#39; could be performed at an optimal level. To achieve this, each healthcare worker in the ICU of Istanbul Medical Faculty was observed directly, and, a comprehensive microbiological investigation was carried out among personnel and of the inanimate environment. The frequency of handwashing was low; 12.9% among medical personnel. Moreover, there was a widespread contamination in the ICU and 28.1% of the healthcare workers were carriers for methicillin-resistant Staphylococcus aureus (MRSA). The factors that contributed to low compliance of handwashing protocols were: a low staff to patient ratio, excessive use of gloves and deficiencies in the infra-structure of ICU. In Heavy workload conditions, alcoholic handrub solutions for quick hand decontamination can be considered as an alternative to handwashing. (C) 2002 The Hospital Infection Society

3,9-dimethyl-1,11-diphenyl-4,8-diaza-undecane-1,11-dione dihydrate

KARA, Hulya/0000-0002-2032-8930WOS: 000082969100052The title compound, C23H26N2O2. 2H(2)O, displays strong intramolecular N-H ... O [2.637(2) Angstrom] and intermolecular O-H ... O [2.763(4) and 2.842(3) Angstrom] hydrogen bonds within each salicylideneimine unit and water molecule. The Schiff base has a twofold axis passing through the central C atom and therefore adopts a cis conformation