Retrospective study of necrotizing fasciitis and characterization of its associated Methicillin-resistant Staphylococcus aureus in Taiwan

<p>Abstract</p> <p>Background</p> <p>Methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) has emerged as a prevalent pathogen of necrotizing fasciitis (NF) in Taiwan. A four-year NF cases and clinical and genetic differences between hospital acquired (HA)- and community-acquired (CA)-MRSA infection and isolates were investigated.</p> <p>Methods</p> <p>A retrospective study of 247 NF cases in 2004-2008 and antimicrobial susceptibilities, staphylococcal chromosomal cassette <it>mec </it>(SCC<it>mec</it>) types, pulsed field gel electrophoresis (PFGE) patterns, virulence factors, and multilocus sequence typing (MLST) of 16 NF-associated MRSA in 2008 were also evaluated.</p> <p>Results</p> <p>In 247 cases, 42 microbial species were identified. <it>S. aureus </it>was the major prevalent pathogen and MRSA accounted for 19.8% of NF cases. Most patients had many coexisting medical conditions, including diabetes mellitus, followed by hypertension, chronic azotemia and chronic hepatic disease in order of decreasing prevalence. Patients with MRSA infection tended to have more severe clinical outcomes in terms of amputation rate (p < 0.05) and reconstruction rate (p = 0.001) than those with methicillin-sensitive <it>S. aureus </it>or non-<it>S. aureus </it>infection. NF patients infected by HA-MRSA had a significantly higher amputation rate, comorbidity, C-reactive protein level, and involvement of lower extremity than those infected by CA-MRSA. In addition to over 90% of MRSA resistant to erythromycin and clindamycin, HA-MRSA was more resistant than CA-MRSA to trimethoprim-sulfamethoxazole (45.8% <it>vs</it>. 4%). ST59/pulsotype C/SCC<it>mec </it>IV and ST239/pulsotype A/SCC<it>mec </it>III isolates were the most prevalent CA- and HA-MRSA, respectively in 16 isolates obtained in 2008. In contrast to the gene for γ-hemolysin found in all MRSA, the gene for Panton-Valentine leukocidin was only identified in ST59 MRSA isolates. Other three virulence factors TSST-1, ETA, and ETB were occasionally identified in MRSA isolates tested.</p> <p>Conclusion</p> <p>NF patients with MRSA infection, especially HA-MRSA infection, had more severe clinical outcomes than those infected by other microbial. The prevalent NF-associated MRSA clones in Taiwan differed distinctly from the most predominant NF-associated USA300 CA-MRSA clone in the USA. Initial empiric antimicrobials with a broad coverage for MRSA should be considered in the treatment of NF patients in an endemic area.</p

Clonal dissemination of the multi-drug resistant Salmonella enterica serovar Braenderup, but not the serovar Bareilly, of prevalent serogroup C1 Salmonella from Taiwan

<p>Abstract</p> <p>Background</p> <p>Nontyphoidal <it>Salmonella </it>is the main cause of human salmonellosis. In order to study the prevalent serogroups and serovars of clinical isolates in Taiwan, 8931 <it>Salmonellae </it>isolates were collected from 19 medical centers and district hospitals throughout the country from 2004 to 2007. The pulsed-field eletrophoresis types (PFGE) and antibiotic resistance profiles of <it>Salmonella enterica </it>serovars Bareilly (<it>S</it>. Bareilly) and Braenderup (<it>S</it>. Braenderup) were compared, and multi-drug resistance (MDR) plasmids were characterized.</p> <p>Results</p> <p>Over 95% of human salmonellosis in Taiwan was caused by five <it>Salmonella </it>serogroups: B, C1, C2-C3, D1, and E1. <it>S</it>. Typhymurium, <it>S</it>. Enteritidis, <it>S</it>. Stanley and <it>S</it>. Newport were the four most prevalent serovars, accounting for about 64% of isolates. While only one or two major serovars from four of the most prevalent serogroups were represented, four predominant serovars were found in serogroup C1 <it>Salmonellae</it>. The prevalence was decreasing for <it>S</it>. Choleraeuis and <it>S</it>. Braenderup, and S. Virchow and increasing for <it>S</it>. Bareilly. <it>S</it>. Braenderup mainly caused gastroenteritis in children; in contrast, <it>S</it>. Bareiley infected children and elderly people. Both serovars differed by <it>Xba</it>I-PFGE patterns. Almost all <it>S</it>. Bareilly isolates were susceptible to antibiotics of interest, while all lacked plasmids and belonged to one clone. Two distinct major clones in <it>S</it>. Braenderup were cluster A, mainly including MDR isolates with large MDR plasmid from North Taiwan, and cluster B, mainly containing susceptible isolates without R plasmid from South Taiwan. In cluster A, there were two types of conjugative R plasmids with sizes ranging from 75 to 130 kb. Type 1 plasmids consisted of replicons F1A/F1B, <it>bla</it>_TEM, IS<it>26</it>, and a class 1 integron with the genes <it>dfrA12</it>-<it>orfF</it>-<it>aadA2-qacE</it>Δ1-<it>sulI</it>. Type 2 plasmids belonged to incompatibility group Inc<it>I</it>, contained <it>tnpA</it>-<it>bla</it>_CMY-2-<it>blc</it>-<it>sugE </it>genetic structures and lacked both IS<it>26 </it>and class 1 integrons. Although type 2 plasmids showed higher conjugation capability, type 1 plasmids were the predominant plasmid.</p> <p>Conclusions</p> <p>Serogroups B, C1, C2-C3, D1, and E1 of <it>Salmonella </it>caused over 95% of human salmonellosis. Two prevalent serovars within serogroup C1, <it>S</it>. Bareilly and cluster B of S. Braenderup, were clonal and drug-susceptible. However, cluster A of <it>S</it>. Braenderup was MDR and probably derived from susceptible isolates by acquiring one of two distinct conjugative R plasmids.</p

Powdery Mildew of Gerbera in Taiwan

在嘉義農業試驗分所栽培之非洲菊發現白粉病，白粉病菌的有性世代並未發現。分生孢子鏈生於孢子梗頂端，無色，單胞，短橢圓形，大小爲20~33.7×15μm (27.7×19.6μm)，含有2~10皿狀物。孢子發芽管短，單出或分叉形。根據其分生孢子特徵，可知本菌屬於Sphaerotheca fuliginea。初步調查，荷蘭Marleen、Veronica、Damco、美國Gigi Mixture等爲較易感病品種。 Powdery mildew of Gerbera jamesonii Bolus was found in February, 1990 at Chiayi, Taiwan. The sexual stage of the powdery mildew fungus in Gerbera was not found in Taiwan. Conidia are formed in chain,. ovoid, 20~33.7×15~25 μm (27.7×19.6 μm) in size, and containing fibrosin bodies. Conidia germinate with a short simple or forked germ tube. According to the characteristics of the Qidium state, Sphaerotheca fuliginea was identified as the causal agent