An epidemic of post-surgical wound infections, caused by a non-tuberculous mycobacterium, has been on-going in Brazil. It has been unclear whether one or multiple lineages are responsible and whether their wide geographical distribution across Brazil is due to spread from a single point source or is the result of human-mediated transmission. 188 isolates, collected from nine Brazilian states, were whole genome sequenced and analysed using phylogenetic and comparative genomic approaches. The isolates from Brazil formed a single clade, which was estimated to have emerged in 2003. We observed temporal and geographic structure within the lineage that enabled us to infer the movement of sub-lineages across Brazil. The genome size of the Brazilian lineage was reduced relative to most strains in the three subspecies of Mycobacterium abscessus and contained a novel plasmid, pMAB02, in addition to the previously described pMAB01 plasmid. One lineage, which emerged just prior to the initial outbreak, is responsible for the epidemic of post-surgical wound infections in Brazil. Phylogenetic analysis indicates that multiple transmission events led to its spread. The presence of a novel plasmid and the reduced genome size suggest that the lineage has undergone adaptation to the surgical niche.

This study evaluated the molecular characteristics of Rhodococcus equi isolates obtained from horses by a multiplex PCR assay that amplifies the vap gene family (vapA, -B, -C, -D, -E, -F, -G, and -H). A total of 180 R. equi isolates were studied from four different sources, namely healthy horse feces (112), soil (12), stalls (23), and clinical isolates (33) from horse-breeding farms. The technique was performed and confirmed by sequencing of amplified vap gene family controls. Thirty-two (17.8%) of the R. equi isolates were positive for the vapA gene and carried at least three other vap genes. All 147 isolates from equine feces, stalls, and soil failed to demonstrate any genes associated with virulence-inducing proteins. About 32 (97.0%) out of the 33 clinical equine isolates tested positive for the multiplex PCR assay for the vap gene family. They demonstrated six molecular profiles: 100% featured the vapA, vapD, and vapG genes, 86.6% vapF, 76.6% vapH, 43.3% vapC, 36.6% vapE, and none vapB. The most frequent molecular profile was vap A, -D, -F, G, and -H, where this profile was present in 37.5% of the strains. Moreover, there was no molecular epidemiological pattern for R. equi isolates that uniquely mapped to each horse-breeding farm studied. Our proposed technique allows the identification of eight members of the vap gene family (vapA, B, -C, -D, -E, -F, -G, and -H). It is a practical and efficient method of conducting clinical and epidemiological studies on R. equi isolates.

These findings suggest a common source of infection for all patients and reinforce the hypotheses of spread of M. massiliense BRA100 in Brazilian hospital surgical environment in recent years.

Tuberculosis is a chronic infection caused by strains of the Mycobacterium tuberculosis complex and occurs in both animal and human populations. The death of a tapir showing purulent material and a hard mass in the lungs at necropsy raised suspicion of a potential disease caused by mycobacteria species in a Brazilian zoo. Later, two other tapirs with similar signs died and were further investigated. Polymerase chain reaction (PCR) from bronco-alveolar lavages was performed, and both animals tested positive for the RD(Rio) strain of M. tuberculosis, which is a recently discovered Latin American-Mediterranean sublineage and the main cause of human tuberculosis in Rio de Janeiro, Brazil. To investigate the possibility of human infection and the source of transmission, all 50 zoo employees underwent tuberculin skin testing; four were reactive, but radiographic exams and direct sample staining did not suggest tuberculosis. Thus, direct human to animal transmission was not proven. However, the presence of RD(Rio) M. tuberculosis in tapirs highlights the lack of attention to diseases that human beings may transmit to wildlife.

Fluoroquinolones (FQs) have been increasingly used for effective treatment of infections caused by rapidly growing mycobacteria, and resistance to this drug has been predominantly attributed to gyrA and gyrB mutations. Accordingly, this study investigated a total of 36 Mycobacterium massiliense clinical isolates for their susceptibility to ciprofloxacin and presence of gyrA and gyrB gene mutations. The minimal inhibitory concentration (MIC) values, determined by broth microdilution method, of 35 ciprofloxacin-resistant isolates ranged between 4 and 16 μg/mL and a single susceptible isolate was obtained. A total of 31 of 35 (88.5%) ciprofloxacin-resistant isolates presented an amino acid substitution at codon 90 (Ala-90→Val) and no isolate presented mutation at position Asp-94. Moreover, 4 of 35 (11.4%) ciprofloxacin-resistant and one susceptible isolate had no mutation in Ala-90 and Asp-94. No gyrB mutation was observed in all tested M. massiliense isolates. In conclusion, our results have shown that mutations of gyrA codon 90 are frequent and may constitute an important mechanism of resistance to FQ in M. massiliense.