Drug resistance of methicillin resistant Staphylococcus strains in burn ward and relative analysis / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the distribution and drug resistance of methicillin resistant Staphylococcus strains in various specimens of inpatients in burn wards, and to provide reference for clinical treatment.</p><p><b>METHODS</b>Bacteria were isolated from specimens of wound exudate, blood, sputum, and bronchoalveolar lavage fluid etc., which were collected from patients hospitalized in our burn wards from January 2008 to December 2010. The bacteria were routinely cultured and identified. Drug resistance of the Staphylococci to 15 antibiotics commonly used in clinic was identified by K-B disk diffusion method. Data were processed with statistical software WHONET 5.5. The homology of 40 strains of methicillin resistant Staphylococcus aureus (MRSA) was analyzed by pulsed-field gel electrophoresis (PFGE).</p><p><b>RESULTS</b>Altogether 386 strains of Staphylococcus were isolated, including 196 strains of Staphylococcus aureus and 190 strains of coagulase negative Staphylococcus. The mean annual isolation rates of MRSA and methicillin resistant coagulase negative Staphylococcus (MRCoNS) were respectively 73.00% (143/196) and 74.20% (141/190). The resistance rates of MRSA and MRCoNS to β-lactams drugs, such as penicillin, oxacillin, cefazolin, and cefuroxime were 100.00% in every year. No Staphylococcus strains resistant to vancomycin, teicoplanin, or linezolid were found. Three different PFGE patterns A, B, and C were identified among 40 MRSA strains, including 33 strains of type A (30 strains in sub-type A1 and 3 strains in sub-type A2), 6 strains of type B (respectively 3 strains in sub-types B1 and B2), and 1 strain of type C.</p><p><b>CONCLUSIONS</b>The isolation rates of MRSA and MRCoNS were high in our burn wards from January 2008 to December 2010. All of them showed strong drug resistance property, and they were multidrug resistant. The most prevalent strain was PFGE type A.</p>

Detection of integron, homology and genotype of carbapenemases in multi-drug resistant Acinetobacter Baumannii isolated from burn wound / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the relationship among antibiotic resistance, integron, homology of multi-drug resistant Acinetobacter Baumannii isolated from burn ward.</p><p><b>METHODS</b>Thirty-one strains of multi-drug resistant Acinetobacter baumannii were isolated from samples of burn wound exudate in hospitalized patients of Gansu Province People's Hospital. The minimum inhibitory concentrations (MIC) of these strains against 11 antibiotics was examined by agar dilution method. Homology of these strains was analyzed by pulse-field gel electrophoresis (PFGE). Class 1, 2 and 3 integrase, integron genes and genotype of carbapenemases were amplified by PCR and verified by DNA sequencing.</p><p><b>RESULTS</b>Acinetobacter baumannii were highly resistant to all antibiotics except imipenem, meropenem, cefoperazone-sulb-actam, piperacillin-tazobactam (antibiotic resistance rate was 45.2%, 48.4%, 48.4%, 41.0%, respectively). All strains were classified into 3 types of clones (A, B, C clone included 18, 7, 6 strains respectively) based on PFGE pattern. Integrons of 20 strains of Acinetobacter Baumannii harbored aadA1, aadA5, aacA4, aac3, catB8, aacC1, aac (6')-Ib, drfA17 and drf8 gene.</p><p><b>CONCLUSION</b>Multi-drug resistance Acinetobacter baumannii (major in clone A) spread widely in burn ward of Gansu Province People's Hospital. Integrons of Acinetobacter baumannii mediated drug resistance against aminoglycoside antibiotics, chloramp-phenicol. All carbapenem-resistant Acinetobacter Baumannii can produce OXA-23 carbapenemase.</p>

Investigation of 728 strains of infectious bacteria in burn ward and analysis of their antibiotic resistance / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the infectious strains of bacteria in our burn ward in recent 5 years, and analyze their antibiotic resistance.</p><p><b>METHODS</b>Bacteria were isolated from the wound excretions of 306 burn patients hospitalized during 2001 to 2006 for analyzing their strains and their antibiotic resistance.</p><p><b>RESULTS</b>378 strains were Grams positive bacteria, among them Staphylococcus aureus was the predominant strain. Further analysis showed that methicillin resistant staphylococcus aureus (MRSA) ranked the first in occurrence, followed by methicillin-resistance Staphylococcus epidermidis (MRSE) and Enterococcus fecalis, 338 strains were Gram negative bacteria, and among them Acinetobacter baumannii was predominant, and Enterobacter cloacae and Pseudomonas aeruginosa ranked the 2nd and 3rd. Twelve strains were fungi.</p><p><b>CONCLUSION</b>Drug resistance to antibiotics in our burn ward may be related to the beta-lactamases from acinetobacter baumannii and multiple-drug-resistance of MRSA.</p>

The isolation of acinetobacter strain from burn wound and the analysis of its antibiotic resistance / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the distribution and drug resistance of acinetobacter isolated from burn wounds.</p><p><b>METHODS</b>The acinetobacter strains were isolated and identified by routine methods. Based on the recommendation of NCCLS, AmpC enzyme was determined by cefoxiti three-dimensional test, ESBLs by disk diffusion method and bacterial susceptibility by Kirby-Bauer agar diffusion method.</p><p><b>RESULTS</b>Among the 69 strains of acinetobacter clinically isolated from burn wounds, 52 were baumannii (75.6%). The acinetobacter strains were identified to be highly resistant to 17 kinds of antibiotics. The drug resistance rate of beta-lactamase-producing strains (68.25%) was higher than that of non-beta-lactamase-producing strains (20.33%). The strains isolated in our burn ward exhibited multiple drug resistance which was mainly due to the production of many kinds of beta-lactamases. Among the 38 strains of beta-lactamase-producing acinetobacter, those producing AmpC beta-lactamase (AmpC BLA) accounted for 42.1%.</p><p><b>CONCLUSION</b>Acinetobacter strain was one of the pathogens in burn wound infection, and its isolation and identification of its drug resistance could be beneficial to the doctors to make right choice of antibiotics.</p>