Fosfomycin Etest for Enterobacteriaceae: Interobserver and interlaboratory agreement.

OBJECTIVES: The increasing use of fosfomycin requires reliable susceptibility testing in clinical practice. The reference standard, agar dilution (AD), is rarely used in routine settings. The fosfomycin Etest (BioMérieux) is frequently used, although reading MICs can be hampered by the interpretation of the growth of macrocolonies in the inhibition zone. We investigated the interobserver (IO), interlaboratory (IL), and interobserver-interlaboratory (IOIL) agreement of the fosfomycin Etest and evaluated the agreement with AD. METHODS: Etests were performed for 57 extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae of four bacterial species (Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and Enterobacter cloacae) in two laboratories. Photographs of fosfomycin Etests were interpreted by four observers following manufacturer's instructions. RESULTS: Essential agreement (EA) and categorical agreement (CA) between Etest and AD were 57% and 89% (κ-value 0.68), respectively, with an underestimation of Etest interpretations compared with AD of 0.26 (95% confidence interval [CI] 0.03-0.48) 2-fold dilutions. Between Etest observations, IO-EA and -CA were reached in 82% and 94% of comparisons; IL-EA and -CA in 38% and 85% of comparisons; and IOIL-EA and -CA in 40% and 85% of comparisons, respectively. Agreement of the Etest with AD and between Etests was better for E. coli than for other species. Ignoring all macrocolonies and haze during Etest interpretation improved the agreement with AD (CA κ-value 0.80) and between Etests (CA κ-value from 0.68 to 0.81). CONCLUSIONS: In this study on 57 ESBL-producing Enterobacteriaceae, IOIL agreement was low with an EA of 40% and a CA of 85%, affected most by IL agreement and to a lesser extent by IO agreement.

An unusual causative pathogen of sepsis after a cat bite: Anaerobiospirillum succiniciproducens.

A 40-year-old woman with a history of liver cirrhosis presented with septic shock caused by an Anaerobiospirillum succiniciproducens bacteraemia after a cat bite. A. succiniciproducens sepsis can develop after a cat or dog bite, especially in immunocompromised hosts, or might occur after translocation from the gut flora. It is a potentially lethal infection.

Bacteraemic and non-bacteraemic/urinary antigen-positive pneumococcal community-acquired pneumonia compared.

The diagnosis of invasive pneumococcal pneumonia is based mainly on bacteraemia. Episodes without bacteraemia, but with a positive urinary antigen test (UAT), are considered non-invasive. We determined differences in outcome between patients with bacteraemic and non-bacteraemic/UAT-positive pneumococcal community-acquired pneumonia (CAP). Adult patients with clinical and radiological evidence of CAP with blood cultures and UAT tests performed at presentation in three Dutch laboratories between June 2008 and May 2010 were included. Clinical characteristics were retrospectively extracted from hospital records. Overall, 168 patients had non-bacteraemic/UAT-positive pneumococcal CAP and 123 had bacteraemic pneumococcal CAP. The day-30 mortality was 9% and 13% for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively [risk difference -4%, 95% confidence interval (CI) -11% to +3%, p = 0.28]. In a multivariable logistic regression model, age ≥ 65 years, admission to the intensive care unit/coronary care unit (ICU/CCU) and presence of an immunocompromising condition were associated with day-30 mortality. A non-significant association with mortality was found for bacteraemia [odds ratio (OR) 2.21, 95% CI 0.94-5.21, p = 0.07). No such trend was found for UAT positivity. The median lengths of hospital stay were 8 [interquartile range (IQR) 5-14] and 10 (IQR 6-18) days for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively (p = 0.05). As compared to non-bacteraemic/UAT-positive pneumococcal CAP, bacteraemic pneumococcal CAP has a stronger association with day-30 mortality.

Increased incidence of serotype-1 invasive pneumococcal disease in young female adults in The Netherlands.

Analysis of the Dutch national invasive pneumococcal disease (IPD) surveillance data by sex reveals an increase in the incidence of serotype-1 disease in young female adults in The Netherlands after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the national immunization schedule. This has led to an overall increase in IPD in women aged 20-45 years, which was not observed in men of the same age. No other differences in serotype shifts possibly induced by the introduction of PCV7 were observed between the sexes in this age group. Serotype 1 is a naturally fluctuating serotype in Europe and it has been associated with disease in young healthy adults before. It remains uncertain whether or not there is an association between the observed increase in serotype-1 disease in young female adults and the implementation of PCV7 in The Netherlands.