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Streptococcus equi subsp. zooepidemicus infections are infrequent in humans. A clinical and epidemiological study of a milk-borne outbreak caused by this organism is described. Fifteen patients (5 females, 10 males) with a median age of 70 years (range 47–86) were infected. Twelve (80%) had underlying diseases. Infection with S. equi subsp. zooepidemicus presented as primary bacteremia in six cases, as bacteremia associated with aortic aneurism in four cases, as septic arthritis in two cases, as pneumonia in two cases, and as meningitis in one case. Five (33.3%) patients died. A case-control study proved that consumption of inadequately pasteurized cheese of a specific brand was associated with S. equi subsp. zooepidemicus disease (OR=4.5; 95% CI 1.57–19.27; p<0.001). This outbreak serves as a reminder that S. equi subsp. zooepidemicus causes serious infections that are usually zoonoses. Identification of beta-hemolytic streptococci to the species level to detect contaminated foods of animal origin is important for preventing new food-borne outbreaks. For a precise characterization of the isolates, the application of molecular markers is recommended. [ABSTRACT FROM AUTHOR]

Achromobacter xylosoxidans is a rare cause of bacteremia. Over a 2-week period, A. xylosoxidans subsp. xylosoxidans was isolated from blood cultures of four hemodialysis patients with long-term intravascular catheters. A culture from one atomizer that contained diluted 2.5% chlorhexidine, which had been used to disinfect the skin, yielded A. xylosoxidans subsp. xylosoxidans. No further cases were diagnosed once the use of this atomizer was discontinued. Five outbreak-related strains from the four patients and the atomizer were tested by pulsed-field gel electrophoresis (PFGE) under XbaI restriction. The isolates from the first three patients and the atomizer had identical PFGE patterns, confirming the atomizer as the source of the outbreak. The strain isolated from the fourth patient had six more bands than the outbreak strain and was considered possibly related to the outbreak strain. All patients were treated with intravenous levofloxacin. The catheter was removed in only one patient. The three patients in whom the catheter was left in place were also treated with antibiotic lock therapy with levofloxacin. All four patients were cured. This is believed to be the first reported outbreak of central venous catheter-related bacteremia due to A. xylosoxidans and the second reported outbreak with this organism associated with chlorhexidine atomizers. The use of diluted chlorhexidine via atomizers can be dangerous for the care of venous catheters and should be called into question. Patients with long-term intravascular catheter-related bacteremia due to this organism can be treated successfully with systemic antimicrobial therapy in addition to antibiotic lock therapy without catheter removal. [ABSTRACT FROM AUTHOR]

This article focuses on rifampin resistance in Streptococcus pyogenes with reference to a study which describes the isolation of rifampin-resistant Streptococcus pyogenes isolated from three related male children in spring 1997. Rifampin is particularly active against gram-positive bacteria and mycobacteria. In the present study, the minimum inhibitory concentration to rifampin was >4 microgram/ml. The isolates with serotype M22 T12 showed the same molecular marker profiles (pulsed-field gel electrophoresis patterns and ribotype) and had a rifampin MIC of >128 microgram/ml. However, two other isolates belonged to M9 T9 and had other pulsed-field gel electrophoresis patterns and ribotype and had a rifampin MIC of 32 microgram/ml.