Corynebacterium guaraldiae sp. nov.: a new species of Corynebacterium from human infections.

Non-diphtheria Corynebacterium species (NDC) belonging to the human skin and mucosa microbiota are frequently neglected as contaminants. However, reports of human infections by Corynebacterium spp. have increased considerably in recent years. In this study, a group of six NDC isolates of urine (n = 5) and sebaceous cyst (n = 1) from two South American countries were identified at genus level or misidentified based on API® Coryne and genetic/molecular analyses. The 16S rRNA (99.09-99.56%) and rpoB (96.18-97.14%) gene sequence similarities of the isolates were higher when compared with Corynebacterium aurimucosum DSM 44532 T. Multilocus sequence analysis (MLSA) indicated that these six NDC isolates compose a distinctive phylogenetic clade. Genome-based taxonomic analysis with the whole-genome sequences was able to separate these six isolates from other known Corynebacterium type strains. Average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values between closely related type strains and the six isolates were considerably lower than the currently recommended threshold values for species circumscription. Phylogenetic and genomic taxonomy analyses indicated these microorganisms as a novel Corynebacterium species, for which we formally propose the name Corynebacterium guaraldiae sp. nov. with isolate 13T (= CBAS 827T = CCBH 35012T) as type strain.

Genomic analysis of Burkholderia cenocepacia isolated from a liver abscess in a patient with cystic fibrosis.

Burkholderia cenocepacia complex is associated with high transmissibility, virulence, and poor prognosis in cystic fibrosis (CF) patients. However, extrapulmonary infections are rare. We investigated the genome of a B. cenocepacia IIIA isolated from a liver abscess in a Brazilian CF patient and compared it to strain J2315. The whole genome was sequenced, and contigs were annotated by Rapid Annotation using Subsystem Technology. The Pathosystems Resource Integration Center was used to map antimicrobial and virulence genes. The genomic island (GIs) analysis was performed using two prediction methods, and the presence of putative plasmids and insertion sequences (ISs) was investigated. The isolate was confirmed as B. cenocepacia IIIA to ST-28 (ET12 lineage). A total of 64 genes for antimicrobial resistance and 47 genes related to virulence were identified. Among the virulence factors, there was a predominance of factors related to the invasion mechanism, to the flagellar biosynthesis protein, and to the RNA polymerase sigma factor for flagellar operon (cdpA). Two IS families (IS3 and IS5) and only one plasmid were found. On average 56 GIs were predicted by at least one of the methods applied. Comparative analysis showed resistance mechanisms and virulence factors revealing invasive determinants used by B. cenocepacia IIIA (ET12) in the process of disease spread to other infection sites (extrapulmonary) of highly virulent strains in CF patients.

Monitoring clinical and microbiological evolution of a cystic fibrosis patient over 26 years: experience of a Brazilian CF Centre.

BACKGROUND: Burkholderia cepacia complex is a group of opportunistic pathogens in cystic fibrosis (CF) patients believed to be associated with poor prognosis and patient-to-patient transmissibility. Little is known about clinical outcomes after B. vietnamiensis chronic colonization/infection. CASE PRESENTATION: A 33 yo male patient had diagnosis of CF by 7 yo, after recurrent pneumonia during infancy and lobectomy (left upper lobe) at 6 yo. Burkholderia cepacia complex (Bcc) was first isolated by 13 yo, and the patient fulfilled the criteria for chronic colonization by 15 yo. In the following 16 years (1997-2013), there was intermittent isolation of P. aeruginosa and continuous isolation of Bcc, identified as B. vietnamiensis. There was clinical and laboratorial stability for 16 years with annual rate of decline in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) of 1.61 and 1.35%, respectively. From 2013 to 2015, there was significant clinical and lung function deterioration: annual rate of decline in FEV1 and FVC was 3 and 4.1%, respectively while body mass index decreased from 18.1 to 17.1. Episodes of hemoptysis and respiratory exacerbations (with hospital admissions) became more frequent. CF related diabetes was diagnosed (fasting glycemia: 116 mg/dL, oral glucose tolerance test: 305 mg/dL). Because of the severity of the disease in the last years, in addition to traditional microbiological surveillance, microbiome analysis by next generation sequencing (NGS) was performed on respiratory secretions. The NGS showed that 97% of the sequencing data were attributed to genus Burkholderia. CONCLUSIONS: We report the case of a 33-year-old male CF patient known to have chronic infection with B. vietnamiensis who remained clinically stable for 16 years and presented recent clinical and laboratorial deterioration. Microbiome analysis of respiratory secretions was performed in 3 samples collected in 2014-2015. Clinical deterioration overlapped with cystic fibrosis-related diabetes and microbiome composition revealed no significant differences when compared microbiome results to culture dependent methods.

Detection and characterization of international community-acquired infections by methicillin-resistant Staphylococcus aureus clones in Rio de Janeiro and Porto Alegre cities causing both community- and hospital-associated diseases.

Community-acquired infections by methicillin-resistant Staphylococcus aureus (CA-MRSA) in the absence of classic risk factors for MRSA diseases have been reported in different continents. In the article presented here, using molecular typing methods as pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec typing, and multilocus sequence typing, we characterized CA-MRSA isolates from Rio Janeiro and Porto Alegre. The results indicated the presence of international CA-MRSA clones in these 2 Brazilian cities. In addition, Panton-Valentine leukocidin and a number of staphylococcal enterotoxin encoding genes were accessed in these MRSA isolates by polymerase chain reaction detection.