Background:Staphylococcus aureus (S. aureus) small colony variants (SCVs) can survive within the host intracellular milieu and are associated with chronic relapsing infections. However, it is unknown whether host invasion rates and immune responses differ between SCVs and their wild-type counterparts. This study used a stable S. aureus SCV (WCH-SK2SCV) developed from a clinical isolate (WCH-SK2...

The pathogen Staphylococcus aureus undergoes phenotype switching in vivo from its normal colony phenotype (NCP) to a slow-growing, antibiotic-resistant small-colony-variant (SCV) phenotype that is associated with persistence in host cells and tissues. However, it is not clear whether phenotype switching is the result of a constitutive process that is selected for under certain conditions or is ...

The spontaneous appearance of unusual colony forms was observed during prolonged growth of Bacteroides gingivalis W50 in a chemostat. Two variants were selected for further study which could be distinguished from the parent strain by the rate and intensity of pigmentation of their colonies. For example, after anaerobic incubation for 14 days, variant W50/BR1 produced brown colonies whereas thos...

Cystic fibrosis (CF) patients are predisposed to chronic respiratory infection by nonfermentative gram-negative bacilli, including Stenotrophomonas maltophilia. S. maltophilia is highly resistant to most antibiotics, with the exception of sulfamethoxazole-trimethoprim (SXT). SXT-resistant S. maltophilia has been reported, but the mechanism of resistance is not well defined. Repeated findings of...

Laboratoire de Bactériologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, Lyon, France Université Claude Bernard Lyon 1, Lyon, France Service de Chirurgie Orthopédique, Centre Albert Trillat, Hôpital de la CroixRousse, Hospices Civils de Lyon, Lyon, France Centre Interrégional de Référence Rhône-Alpes Auvergne des Infections Ostéoarticulaires complexes, Lyon, France Centre Internationa...

Small colony variant (SCV) Staphylococcus aureus are a subpopulation of auxotroph, slow-growing strains causing persisting and relapsing infections in cystic fibrosis (CF) patients. Twenty-eight SCV and 29 normal S. aureus strains were isolated from 42 out of 222 Italian CF patients. The isolates were characterized for: susceptibility to antibiotics, methicillin-resistance (MR), Panton Valentin...

Staphylococcus aureus remains a versatile and dangerous pathogen. Small-colony variants (SCVs) of S. aureus are a naturally occurring sub-population, first described nearly 100 years ago. These variants, of which there are different classes, grow slowly and have many atypical characteristics thought to be due to defective electron transport, and include minute colony forms. SCVs have been isola...

A modified variant of gray wolf optimization algorithm, namely, mean gray wolf optimization algorithm has been developed by modifying the position update (encircling behavior) equations of gray wolf optimization algorithm. The proposed variant has been tested on 23 standard benchmark well-known test functions (unimodal, multimodal, and fixed-dimension multimodal), and the performance of modifie...

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Two small cell lung cancer (SCLC) cell lines were established from pericardial and pleural effusions of a patient with histopathologically proven SCLC of the oat cell type. Chemotherapy was administered without response during the 148-day period prior to the establishment of the first cell line, SCLC-22H, and some of the same drugs were administered in the 15 days prior to the establishment of ...