How often is a work-up for Legionella pursued in patients with pneumonia? A retrospective study

<p>Abstract</p> <p>Background</p> <p>It is unclear how often patients with pneumonia are assessed for <it>Legionella </it>in endemic areas. Additionally, the sensitivity of the IDSA/ATS criteria for recommended <it>Legionella </it>testing is undefined.</p> <p>Methods</p> <p>We performed a single-center, retrospective study of patients diagnosed with <it>Legionella </it>pneumonia at our hospital to determine: 1) how often <it>Legionella </it>diagnostic testing is obtained on patients with pneumonia at the time of hospitalization or when pneumonia developed during hospitalization; and 2) how often patient's with <it>Legionella </it>pneumonia met at least one of the five criteria in the IDSA/ATS guidelines recommending a work-up for <it>Legionella</it>. Patients with <it>Legionella </it>pneumonia were identified using an infection control software program. Medical records of these patients were then reviewed.</p> <p>Results</p> <p>Thirty-five percent of patients with a discharge diagnosis of pneumonia had <it>Legionella </it>urine antigen testing and/or a <it>Legionella </it>culture performed. Forty-four percent of patients who had a bronchoscopic specimen sent for microbiologic testing had a <it>Legionella </it>culture performed on the bronchoscopic specimen and/or <it>Legionella </it>urine antigen testing. Of 37 adult patients with <it>Legionella </it>pneumonia, 22 (59%) met the IDSA-ATS criteria recommending <it>Legionella </it>testing.</p> <p>Conclusion</p> <p>Following current recommendations for <it>Legionella </it>testing missed 41% of <it>Legionella </it>cases in adults in our single-center study. A work-up for <it>Legionella </it>(i.e., urine antigen test and/or culture) was performed in less than half of patients who have a bronchoscopic specimen sent for microbiologic testing.</p

Molecular epidemiology of CTX-M-producing escherichia coli isolates at a tertiary medical center in western pennsylvania

A combination of phenotypic and genotypic methods was used to investigate 70 unique Escherichia coli clinical isolates identified as producing extended-spectrum beta-lactamases (ESBLs) at a medical center in Pittsburgh, PA, between 2007 and 2008. Fifty-seven isolates (81%) produced CTX-M-type ESBLs, among which CTX-M-15 was predominant (n = 46). Isolates producing CTX-M-2, -9, -14, and -65 were also identified. One CTX-M-producing isolate coproduced CMY-2 cephalosporinase. Ten isolates (14%) produced SHV-type ESBLs, either SHV-5 or SHV-7. Two isolates produced only CMY-2 or -32. Pulsed-field gel electrophoresis revealed the presence of two major clusters of CTX-M-15-producing E. coli isolates, one in phylotype B2 (n = 15) and the other in phylotype A (n = 19). Of four phylotype B2 isolates that were able to transfer the bla(CTX-M-15)-carrying plasmids, three showed fingerprints related (>60%) to those of plasmids from phylotype A isolates. In phylotype B2, all CTX-M-15-producing isolates, as well as three isolates producing CTX-M-14, two producing SHV-5, and one producing SHV-7, belonged to the international epidemic clone defined by serotype O25:H4 and sequence type 131. The plasmids from eight of nine CTX-M-15-producing E. coli isolates of phylotype A that were examined were highly related to each other and were also found in two isolates belonging to phylotype D, suggesting horizontal transfer of this bla(CTX-M-15)-carrying plasmid between phylotypes. Our findings underscore the need to further investigate the epidemiology and virulence of CTX-M-producing E. coli in the United States