In searching for an alternative antibacterial agent against multidrug-resistant Staphylococcus aureus, we have isolated and characterized a lytic staphylophage, Stau2. It possesses a double-stranded DNA genome estimated to be about 134.5 kb and a morphology resembling that of members of the family Myoviridae. With an estimated latency period of 25 min and a burst size of 100 PFU/infected cell, propagation of Stau2 in liquid culture gave a lysate of ca. 6 ؋ 10 10 PFU/ml. It was stable at pH 5 to 13 in normal saline at room temperature for at least 4 weeks and at ؊85°C for more than 2 years, while 1 ؋ 10 9 out of 2 ؋ 10 12 PFU/ml retained infectivity after 36 months at 4°C. Stau2 could lyse 80% of the S. aureus isolates (164/205) obtained from hospitals in Taiwan, with complete lysis of most of the isolates tested within 3 h; however, it was an S. aureus-specific phage because no lytic infection could be found in the coagulase-negative staphylococci tested. Its host range among S. aureus isolates was wider than that of polyvalent phage K (47%), which can also lyse many other staphylococcal species. Experiments with mice demonstrated that Stau2 could provide 100% protection from lethal infection when a multiplicity of infection of 10 was administered immediately after a challenge with S. aureus S23. Considering these results, Stau2 could be considered at least as a candidate for topical phage therapy or an additive in the food industry.

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Both Vitek 2 and MALDI-TOF MS methods showed good ability in the determination of C. indologenes. Among the examined drugs, minocycline was the most potent one. As many as 38.2% C. indologenes isolates showed biofilm-forming ability. PFGE analyses revealed the possible intrahospital transmission of this bacterium in central Taiwan.

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This study was conducted to detect the genes encoding extended-spectrum b-lactamases (ESBLs) and determine the epidemiological relatedness of 69 Escherichia coli and 33 Klebsiella pneumoniae isolates collected from a regional hospital in central Taiwan, mostly from inpatients (E. coli 87.0 %; K. pneumoniae 88.0 %). The phenotypes of these isolates were examined according to the combination disc method recommended by the Clinical and Laboratory Standards Institute. Most of the ESBL-producing E. coli and K. pneumoniae isolates (98.6 % and 97 %, respectively) could be detected using cefotaxime discs with and without clavulanate. Genotyping was performed by PCR with type-specific primers. CTX-M-14 type (53.6 %) was the most prevalent ESBL among E. coli isolates while SHV type (57.6 %) was the most dominant among K. pneumoniae isolates. Six E. coli and three K. pneumoniae isolates did not carry genes encoding ESBLs of types TEM, SHV, CTX-M-3, CTX-M-14, CMY-2 and DHA-1. The co-existence of two or more kinds of ESBL in a single isolate was common, occurring in 40.6 % and 72.7 % of E. coli and K. pneumoniae isolates, respectively. PFGE analysis revealed that ESBL producers isolated in this setting were genetically divergent. INTRODUCTIONSince the first report in Germany in 1983 (Knothe et al., 1983), the emergence of extended-spectrum b-lactamase (ESBL)-producing Klebsiella pneumoniae and Escherichia coli has become a serious problem in hospitalized patients worldwide (Hawser et al., 2009;Livermore et al., 2007;Paterson & Bonomo, 2005). In Taiwan, the prevalence of ESBL producers has increased in recent years, ranging from 8.5 to 50.7 % in K. pneumoniae and 1.5 to 25.4 % in E. coli (Jean et al., 2009;Kuo et al., 2008;Yu et al., 2006).According to Ambler's classification, ESBLs belong to the class A b-lactamases, which possess an active-site serine residue essential for the inactivation of b-lactam antimicrobial drugs (Ambler, 1980). The term 'extendedspectrum b-lactamase' was originally applied to describe the TEM and SHV variants that can hydrolyse oxyiminocephalosporins (Paterson & Bonomo, 2005). The 'extended spectrum' of activity is defined in terms of hydrolysing oxyimino-cephalosporins or aztreonam at more than 10 % of the activity of hydrolysing benzylpenicillin. Generally, ESBLs confer resistance to all penicillins, first-to-fourth generation cephalosporins and monobactams, but not to cephamycins or carbapenems. However, like many other class A b-lactamases, ESBLs are inactivated by the blactamase inhibitors, such as clavulanate (Bradford, 2001). Most of the genes encoding ESBLs are plasmid-borne and are often located in the transposons and integrons (Eckert et al., 2006), facilitating their mobilization with other resistance determinant. Thus the genes encoding ESBLs may be easily transferred between bacteria.The most prevalent ESBLs are included in three groups: TEM, SHV and CTX-M. The SHV enzymes are named Isoelectric focusing. Bacteria cultured in Mueller-Hinton broth for 20 h were centrifuged and the pellet...