Genomic epidemiology of a national outbreak of post-surgical Mycobacterium abscessus wound infections in Brazil.

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.

Bronchopneumonia in wild boar (Sus scrofa) caused by Rhodococcus equi carrying the VapB type 8 plasmid.

BACKGROUND: Rhodococcus equi is associated with pyogranulomatous infections, especially in foals, and this bacterium has also emerged as a pathogen for humans, particularly immunocompromised patients. R. equi infections in pigs, wild boar (Sus scrofa) and humans are mainly due to strains carrying the intermediate virulence (VapB) plasmid. In Brazil, R. equi carrying the VapB type 8 plasmid is the most common type recovered from humans co-infected with the human immunodeficiency virus (HIV). R. equi infection in pigs and wild boar is restricted predominantly to the lymphatic system, without any reports of pulmonary manifestations. FINDINGS: This report describes the microbiological and histopathological findings, and molecular characterization of R. equi in two bronchopneumonia cases in wild boar using PCR and plasmid profile analysis by digestion with restriction endonucleases. The histological findings were suggestive of pyogranulomatous infection, and the plasmid profile of both R. equi isolates enabled the characterization of the strains as VapB type 8. CONCLUSIONS: This is the first report of bronchopneumonia in wild boar due to R. equi. The detection of the VapB type 8 plasmid in R. equi isolates emphasize that wild boar may be a potential source of pathogenic R. equi strains for humans.

An outbreak of tuberculosis by Mycobacterium bovis in coatis (Nasua nasua).

Mycobacterium tuberculosis complex, which includes Mycobacterium bovis, infrequently causes severe or lethal disease in captive wildlife populations. A dead coati from a wildlife triage center showing pulmonary lesions compatible with tuberculosis had raised suspicion of a potential disease caused by mycobacteria species and was further investigated. Four native coatis (Nasua nasua) with suspected mycobacterial infection were sedated, and bronchoalveolar lavages and tuberculin skin tests (TSTs) were performed. All animals tested positive upon TST. Mycobacterial culturing, Ziehl-Neelsen staining, and genetic testing were performed on postmortem samples and the etiologic agent was identified as M. bovis. Molecular genetic identification using a polymerase chain reaction panel was crucial to achieving a definitive diagnosis.

gyrA and gyrB gene mutation in ciprofloxacin-resistant Mycobacterium massiliense clinical isolates from Southern Brazil.

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.

Detection of RD(Rio) strain of Mycobacterium tuberculosis in tapirs (Tapirus terrestris) from a zoo in Brazil.

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.

Molecular identification and typing of Mycobacterium massiliense isolated from postsurgical infections in Brazil

OBJECTIVE: One hundred thirty-one cases of postsurgical infections were reported in Southern Region of Brazil between August 2007 and January 2008. Thirty-nine (29.8 percent) cases were studied; this report describes epidemiological findings, species identification, antimicrobial susceptibility and clonal diversity of rapidly growing mycobacteria isolated in this outbreak. METHODS: All 39 isolates were analyzed by Ziehl-Nielsen stained smear, bacterial culture and submitted to rpoB partial gene sequencing for identification. The isolates were also evaluated for their susceptibility to amikacin, cefoxitin, clarithromycin, ciprofloxacin, doxycycline, tobramycin and sulfamethoxazole. RESULTS: Thirty-six isolates out of the confirmed cases were identified as Mycobacterium massilienseand the remaining three were identified as Mycobacterium abscessus, Mycobacterium chelonae and Mycobacterium fortuitum. All M. massiliense isolates were susceptible to amikacin (MIC90 = 8 µg/mL) and clarithromycin (MIC90 = 0.25 µg/mL) but resistant to cefoxitin, ciprofloxacin, doxycycline, tobramycin and sulfamethoxazole. Molecular analysis by pulsed-field gel electrophoresis clustered all 36 M. massiliense isolates and showed the same pattern (BRA 100) observed in three other outbreaks previously reported in Brazil. CONCLUSIONS: 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.

Molecular identification and typing of Mycobacterium massiliense isolated from postsurgical infections in Brazil.

OBJECTIVE: One hundred thirty-one cases of postsurgical infections were reported in Southern Region of Brazil between August 2007 and January 2008. Thirty-nine (29.8%) cases were studied; this report describes epidemiological findings, species identification, antimicrobial susceptibility and clonal diversity of rapidly growing mycobacteria isolated in this outbreak. METHODS: All 39 isolates were analyzed by Ziehl-Nielsen stained smear, bacterial culture and submitted to rpoB partial gene sequencing for identification. The isolates were also evaluated for their susceptibility to amikacin, cefoxitin, clarithromycin, ciprofloxacin, doxycycline, tobramycin and sulfamethoxazole. RESULTS: Thirty-six isolates out of the confirmed cases were identified as Mycobacterium massiliense and the remaining three were identified as Mycobacterium abscessus, Mycobacterium chelonae and Mycobacterium fortuitum. All M. massiliense isolates were susceptible to amikacin (MIC90 = 8 µg/mL) and clarithromycin (MIC90 = 0.25 µg/mL) but resistant to cefoxitin, ciprofloxacin, doxycycline, tobramycin and sulfamethoxazole. Molecular analysis by pulsed-field gel electrophoresis clustered all 36 M. massiliense isolates and showed the same pattern (BRA 100) observed in three other outbreaks previously reported in Brazil. CONCLUSIONS: 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.

Epidemiologic pattern of patients with neurocysticercosis diagnosed by computed tomography in Curitiba, Brazil.

The aim of this study was to drawn an epidemiological pattern of neurocystisticercosis (NCC) patients diagnosed by computed tomography at the major private diagnostic center in Curitiba, Brazil. A total of 1,009 medical files of consecutive patients presenting neurological indications were diagnosed by computed tomography from July 2007 to April 2008. Patient data included sex, age, municipality and tomography findings were analysed by Epi-info version 6.0.1. software. Most patients (81.10%) were living in Curitiba. A total of 91/1,009 cases (9.02%) were considered positive to NCC; 88 (96.7%) patients had inactive form of NCC and only 3 (3.2%) patients had cysts in granulomatous process. No patients had both forms. The prevalence of NCC cases in studied group was greater in patients between 51 to 60 years old, however, difference between sex was not significant. This epidemiological pattern of NCC was similar to the first NCC study in Curitiba, performed in 1995-1996 with 9.24% of positive cases.

Epidemiologic pattern of patients with neurocysticercosis diagnosed by computed tomography in Curitiba, Brazil / Perfil epidemiológico de pacientes com neurocisticercose diagnosticados por tomografia computadorizada em Curitiba, Brazil

The aim of this study was to drawn an epidemiological pattern of neurocystisticercosis (NCC) patients diagnosed by computed tomography at the major private diagnostic center in Curitiba, Brazil. A total of 1,009 medical files of consecutive patients presenting neurological indications were diagnosed by computed tomography from July 2007 to April 2008. Patient data included sex, age, municipality and tomography findings were analysed by Epi-info version 6.0.1. software. Most patients (81.10 percent) were living in Curitiba. A total of 91/1,009 cases (9.02 percent) were considered positive to NCC; 88 (96.7 percent) patients had inactive form of NCC and only 3 (3.2 percent) patients had cysts in granulomatous process. No patients had both forms. The prevalence of NCC cases in studied group was greater in patients between 51 to 60 years old, however, difference between sex was not significant. This epidemiological pattern of NCC was similar to the first NCC study in Curitiba, performed in 1995-1996 with 9.24 percent of positive cases.

Determinou-se o perfil epidemiológico da neurocisticercose (NCC) em pacientes diagnosticados por tomografia computadorizada (TC) no maior centro privado de diagnósticos de Curitiba, Brasil. Foram analisados 1009 registros médicos de pacientes consecutivos com indicações neurológicas submetidos a TC entre julho de 2007 a abril de 2008. Os dados dos pacientes que incluíram sexo, idade, município de residência e achados tomográficos foram analisados pelo software Epi-info versão 6.01. A maioria dos pacientes (80,10 por cento) era procedente de Curitiba; 91/1.009 casos (9,02 por cento) foram positivos para NCC; 88 (96,7 por cento) apresentaram a forma inativa e apenas em 3 (3,2 por cento) cistos em processo granulomatoso; não houve formas mistas. A prevalência de casos de NCC foi maior entre 51 e 60 anos. Não houve diferença significativa para o sexo entre os casos. O perfil dos pacientes diagnosticados para NCC por TC neste estudo é semelhante ao estudo anterior realizado em Curitiba entre 1995-1996, com 9,24 por cento de casos de NCC.

Surto de listeriose sistêmica em chinchilas / Outbreak of systemic listeriosis in chinchillas

A listeriose é uma doença infecciosa que afeta uma grande variedade de espécies animais, causando septicemia, encefalite e aborto. As chinchilas são os animais mais susceptíveis à infecção sistêmica por Listeria monocytogenes. Este relato descreve um surto de listeriose sistêmica em uma criação de chinchilas da região central do Estado do Rio Grande do Sul, onde cerca de 16 por cento das chinchilas morreram. Na necropsia, havia múltiplos focos brancos, pequenos e de distribuição aleatória nas superfícies capsular e de corte do fígado e aumento de volume do linfonodo hepático. Histologicamente, observaram-se hepatite necrossupurativa e linfadenite supurativa multifocais, com numerosos bacilos intralesionais. L. monocytogenes foi o agente etiológico do surto de listeriose sistêmica, sendo o diagnóstico confirmado por meio das lesões de necropsia e histopatológicas, das características fenotípicas e genotípicas da bactéria e da técnica de imuno-histoquímica.

Listeriosis is an infectious disease, which affects a variety of animal species and cause septicemia, encephalitis and abortion. Chinchillas are the most susceptible animals to the systemic infection by Listeria monocytogenes. This report describes an outbreak of systemic listeriosis in a farm of chinchillas in the Central region of the Rio Grande do Sul state, Brazil. Mortality rate was about 16 percent. On necropsy, there were multiple random small white foci on the liver capsule and parenchyma and enlargement of the hepatic lymph node. Histologically, there were multifocal necro-suppurative hepatitis and suppurative lymphadenitis with numerous intralesional bacilli. L. monocytogenes was the etiology of the systemic listeriosis outbreak. The diagnosis was based on gross and microscopic lesions, genotypical and phenotypical characteristics and by immunohistochemistry technique.

Molecular characterization of Rhodococcus equi from horse-breeding farms by means of multiplex PCR for the vap gene family.

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.