Staphylococcus simulans associated with endocarditis in broiler chickens.

This report suggests a strong association between coagulase-negative Staphylococcus simulans and endocarditis in broiler chickens of a single flock. Clinical signs included increased mortality and lameness, and some dead chickens were found on their backs. Lesions included cauliflower-like, fibrinous vegetative lesions on the left atrioventricular valve; cream-coloured, necrotic foci of varying size in the liver; and necrosis of the femoral head. Histopathological examination of the heart revealed multifocal conglomerates of bacterial colonies attached to the valvular endocardium, threads of fibrin, and inflammatory cells with the presence of heterophils. S. simulans strains were first identified by API ID32, and then confirmed with Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and by partial sequencing of the rpoB and dnaJ genes. These bacteria were resistant to methicillin but sensitive to vancomycin and characterized by slime production and protease activity.

Nasopharyngeal vs. adenoid cultures in children undergoing adenoidectomy: prevalence of bacterial pathogens, their interactions and risk factors.

Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus colonization of the adenoids and nasopharynx in 103 preschool children who underwent adenoidectomy for recurrent upper respiratory tract infections was examined. Bacterial interactions and risk factors for bacterial colonization of the nasopharynx and adenoids, separately, were analysed statistically. The prevalence of simultaneous isolation from both anatomical sites was 45·6% for S. pneumoniae, 29·1% for H. influenzae, 15·5% for M. catarrhalis and 18·4% for S. aureus. Three pathogens were significantly more frequent together from adenoid samples; nasopharyngeal swabs more often yielded a single organism, but without statistical significance. M. catarrhalis and S. aureus significantly more frequently co-existed with S. pneumoniae and H. influenzae than with each other and a positive association of S. pneumoniae and H. influenzae in adenoid samples was evident. Several differences between risk factors for nasopharyngeal and adenoid colonization by the individual pathogens were observed. We conclude that the adenoids and nasopharynx appear to differ substantially in colonization by pathogenic microbes but occurrence of H. influenzae and S. pneumoniae in the nasopharynx could be predictive of upper respiratory tract infections.

A loop-mediated isothermal amplification procedure targeting the sodA gene for rapid and specific identification of Gallibacterium anatis.

This paper reports on the development and validation of a real-time loop-mediated isothermal amplification assay (LAMP) for rapid and specific identification of Gallibacterium anatis. To design a set of 6 primers using the LAMP technique, the conserved region of the G. anatis sodA gene was selected as a target. To evaluate primer specificity we used 120 field strains, the reference strain G. anatis ATCC 43329, and 9 non-G. anatis bacteria. The results confirmed positive reactions for all G. anatis strains tested by LAMP at 63°C for 60 min, with no cross-reactivity observed for the negative control bacteria, i.e., Haemophilus parainfluenzae (ATCC 51505 and ATCC 33392), Aggregatibacter aphrophilus ATCC 7901, Avibacterium endocarditis, Pasteurella multocida, Actinobacillus pleuropneumoniae, Avibacterium paragallinarum, Ornithobacterium rhinotracheale, and Escherichia coli. The lowest detectable amount of DNA for the LAMP reaction was 0.2561 pg, which was detected in about 34 min, while the highest available concentration of the G. anatis reference strain was detected in about 10 min. The lowest detectable amount of DNA for the real-time PCR reaction was 21.24 pg, which was detected in about 20 min, while the highest available concentration of the G. anatis reference strain was detected in about 7 min. Moreover, using the real-time LAMP assay the reaction could be effectively carried out in a volume of just 13 µL, about half the officially recommended reaction volume (25 µL). The aim of this study was to develop a highly sensitive and specific G. anatis real-time LAMP assay that is less time-consuming and less costly than quantitative PCR.

Substrate-dependent cadmium toxicity affecting energy-linked K+/86Rb transport in Staphylococcus aureus.

Bacteria accumulate high amounts of potassium in the cytoplasm. For studying transport of K+ (with 86Rb as a marker) in bacteria (Staphylococcus aureus 17810S), the cells were depleted of the internal K+ pool by a DNP treatment. Kinetics and energetics of 86Rb transport was assayed with glucose as an exogenous energy source. It was shown that 86Rb uptake proceeded via a low affinity K+ transport system with an apparent K(m) of 2.3 mmol/L Rb+. Studies with the lipophilic cation TPP+ (tetraphenylphosphonium), the protonophore CCCP (carbonyl cyanide 3-chlorophenylhydrazone) and inhibitors (HQNO--2-heptyl-4-hydroxyquinoline N-oxide; iodoacetate) indicated that 86Rb transport was driven by delta psi (membrane potential) generated via the respiratory chain. The effect of Cd2+ on 86Rb transport was assayed with two energy donors--glucose and L-lactate. It was found that Cd2+ strongly inhibited delta psi-dependent 86Rb transport energized by cadmium-sensitive glucose oxidation, but was not toxic when cadmium-insensitive L-lactate was used as an energy source. The mechanism of these differential, substrate-dependent effects of Cd2+ on 86Rb transport is discussed.