Secondary transfer and expression of vanA in Enterococcus faecium derived from a commensal vancomycin-susceptible Enterococcus faecium multi-component food isolate.

We investigated the potential for vancomycin-susceptible Enterococcus (VSE) from multi-component salads to disseminate vanA from four clinical vancomycin-resistant enterococci to 14 streptogramin-resistant enterococci (SRE) of food and animal origin. Strains were selected from a previous study based on the presence of streptogramin susceptibility and/or vanA, vanB, vatD, vatE, agg, cpd, and gelE genes. Transconjugants were isolated on brain heart infusion agar containing vancomycin and selective antibiotics. Thirty-nine matings using a 1:10 donor-recipient ratio for filter and broth methods resulted in transfer of vanA between an agg(+)cpd(+)gelE(+) Enterococcus faecalis donor and an agg(-)cpd(-)gelE(-) streptogramin-susceptible Enterococcus faecium salad recipient at a frequency of 10(-8) per recipient by filter method. Secondary mating of the transconjugant with SR/VSE strains resulted in a two- to four-log-fold greater frequency of transfer. Reverse transcription-polymerase chain reaction revealed vanA RNA products in the transconjugant cultivated in nutrient broth and salad at 37°C in the presence and absence of recipient filtrate. This study demonstrated that native salad VSE disseminated vanA to SRE carrying agg, cpd, and/or gelE. An increase in transfer efficiency resulted from secondary conjugation using the native vancomycin- and streptogramin-susceptible salad strain as the donor.

Unusual forms of immature sporulating Coccidioides immitis diagnosed by fine-needle aspiration biopsy.

Coccidioidomycosis is an endemic infection acquired by inhalation of the spores (arthroconidia) of the thermally dimorphic fungus, Coccidioides immitis. The arthroconidia transform into spherical cells called mature spherules in the lung. Immature spherules and other atypical forms of immature C immitis have rarely been found in vivo. We report on a case that presented unusual forms of immature sporulating C immitis in a fine-needle aspiration specimen. A 36-year-old Chinese woman, living in New Jersey for the past 10 years, presented with fever, night sweats, hemoptysis, and an abnormal chest radiograph approximately 9 months after a brief vacation trip to the Grand Canyon in Arizona. She was treated with antibiotics for 4 weeks without improvement. Subsequent chest computed tomography showed a 3-cm cavitary lesion in the right lower lobe of the lung. Fine-needle aspiration biopsy revealed diverse morphologic forms of a fungus that was confirmed by culture as immature sporulating C immitis.

Utility of extended blood culture incubation for isolation of Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella organisms: a retrospective multicenter evaluation.

The incidence of and average time to detection for Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella (HACEK) bacteria in blood cultures with standard incubation and the utility of extended incubation of blood culture bottles were reviewed at four tertiary care microbiology laboratories. HACEK organisms were isolated from 35 (<0.005%) of 59,203 positive blood cultures. None of 407 blood cultures with extended incubation grew HACEK or other bacteria. Bacteremia from HACEK bacteria is rare, and extended incubation of blood cultures to recover HACEK bacteria is unnecessary.