Corynebacterium striatum is a potentially pathogenic microorganism with the ability to produce outbreaks of nosocomial infections. Here, we document a nosocomial outbreak caused by multidrug-resistant (MDR) C. striatum in Rio de Janeiro, Brazil. C. striatum identification was confirmed by 16S rRNA and rpoB gene sequencing. Fifteen C. striatum strains were isolated from adults (half of whom were 50 years of age and older). C. striatum was mostly isolated in pure culture from tracheal aspirates of patients undergoing endotracheal intubation procedures. The analysis by pulsed-field gel electrophoresis (PFGE) indicated the presence of four PFGE profiles, including two related clones of MDR strains (PFGE I and II). The data demonstrated the predominance of PFGE type I, comprising 11 MDR isolates that were mostly isolated from intensive care units and surgical wards. A potential causal link between death and MDR C. striatum (PFGE types I and II) infection was observed in five cases.

Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respiratory disease and is associated with high mortality in compromised hosts. Little is known about the virulence factors and pathogenesis of C. pseudodiphtheriticum. In this study, cultured human epithelial (HEp-2) cells were used to analyse the adherence pattern, internalisation and intracellular survival of the ATCC 10700 type strain and two additional clinical isolates. These microorganisms exhibited an aggregative adherence-like pattern to HEp-2 cells characterised by clumps of bacteria with a "stacked-brick" appearance. The differences in the ability of these microorganisms to invade and survive within HEp-2 cells and replicate in the extracellular environment up to 24 h post infection were evaluated. The fluorescent actin staining test demonstrated that actin polymerisation is involved in the internalisation of the C. pseudodiphtheriticum strains. The depolymerisation of microfilaments by cytochalasin E significantly reduced the internalisation of C. pseudodiphtheriticum by HEp-2 cells. Bacterial internalisation and cytoskeletal rearrangement seemed to be partially triggered by the activation of tyrosine kinase activity. Although C. pseudodiphtheriticum strains did not demonstrate an ability to replicate intracellularly, HEp-2 cells were unable to fully clear the pathogen within 24 h. These characteristics may explain how some C. pseudodiphtheriticum strains cause severe infection in human patients.

A caracterização fenotípica, perfil de sensibilidade aos antimicrobianos e aspectos clínico-epidemiológicos foram avaliados em 28 linhagens de Nocardia isoladas de 19 casos de mastite, oito lesões tegumentares e um caso de pneumonia em cão. Foram utilizados no diagnóstico métodos microbiológicos, bioquímicos, citológicos e microscopia eletrônica de varredura. Nocardia asteroides tipo IV, N. otitidiscaviarum,N. nova (tipo III) e N. farcinica (tipo V) foram isoladas do leite de vacas com mastite, de material de lavado transtraqueal e de lesões cutâneas de cães. Nocardiose mamária bovina foi diagnosticada predominantemente sob a forma clínica, em propriedades com precárias condições de higiene na pré e pós-ordenha, e inadequado procedimento de terapia intramamária. Nocardiose canina foi diagnosticada comumente em animais co-infectados com o vírus da cinomose. Sulfametoxazole/trimetoprim (92,8%), amicacina (92,8%) e ceftiofur (92,8%) foram os antimicrobianos mais efetivos frente às linhagens de Nocardia. Resistência múltipla a três ou mais e cinco ou mais antimicrobianos foram observadas, respectivamente, em dez (35,7%) e três (10,7%) linhagens, notadamente frente à cloxacilina, cefoperazona e ampicilina. A caracterização de espécies (tipo), aspectos clínico-epidemiológicos, diagnóstico, resistência múltipla aos antimicrobianos e reflexos em saúde pública de linhagens de Nocardia isoladas de bovinos e cães no Brasil foram discutidos. Foi destacada a similaridade entre as espécies de Nocardia isoladas de animais e do homem, e a primeira descrição no Brasil de N. otitidiscaviarum na etiologia da mastite bovina.

Phenotypic characteristics, antimicrobial susceptibility profile, and clinical-epidemiological features of 28 Nocardia strains isolated from 19 cases of bovine mastitis, eight cutaneous-subcutaneous lesions and one case of pneumonia in dogs were evaluated. Microbiological, biochemical, cytological and scanning electron microscopy methods were used in diagnosis. Nocardia asteroides type IV, Nocardia otitidiscaviarum,Nocardia nova (type III) and Nocardia farcinica (type V) were isolated from bovine milk, bronchial lavage and/or cutaneous-subcutaneous abscesses in dogs. Nocardial bovine mastitis was diagnosed predominantly in clinical cases, in dairy herds with poor environmental hygienic conditions between milking and inappropriate intramammary therapy. Canine nocardiosis was observed commonly in animals co-infected with distemper virus. Sulphamethoxazole-trimethoprim (92.8%), amikacin (92.8%) and ceftiofur (92.8%) were the most effective drugs in 28 isolates. Multiple drug resistance to three or more and five or more antimicrobials was observed in ten (35.7%) and three (10.7%) strains, respectively, predominantly with use of cloxaxillin, cefoperazone and ampicillin. The species (type) classification, clinical-epidemiological characteristics, diagnosis, multiple-drug resistance and public health considerations in Nocardia strains isolated from cattle and dogs in Brazil are discussed, with special reference to report of bovine mastitis by N. otitidiscaviarum by first time in Brazil and the similarity between Nocardia species isolated from human and animal origin.

Durante um período de cinco anos, foram isoladas 163 amostras de Corynebacterium sp. a partir de espécimes clínicos obtidos de pacientes de um Hospital Universitário brasileiro. Os microrganismos foram predominantemente observados (46.62%) em materiais oriundos de sítios intravenosos e trato geniturinário. Amostras de Corynebacterium amycolatum (29.55%), Corynebacterium minutissimum (20.45%) e Corynebacterium pseudodiphtheriticum (13.63%) foram predominantemente isoladas do trato geniturinário; C. minutissimum (24.14%) e Corynebacterium propinquum (17.24%) de feridas cirúrgicas e/ou outras lesões cutâneas e abscessos; Corynebacterium xerosis (25%), C. amycolatum (21.87%) e C. pseudodiphtheriticum (18.75%) de sítios intravenosos; C. pseudodiphtheriticum (33.33%) e C. propinquum (33.33%) do trato respiratório inferior. A maioria das espécies exibiu resistência a antimicrobianos do grupo dos beta-lactâmicos e todas as amostras foram vancomicina-sensíveis. Dentre as espécies de corinebactérias isoladas, as amostras exibiram perfis heterogêneos de susceptibilidade aos antimicrobianos. Além de C. jeikeium, a multirresistência aos antimicrobianos também foi observada em amostras de C. xerosis, C. minutissimum, C. afermentans, C. propinquum, C. amycolatum e C. pseudodiphtheriticum. Os dados enfatizam a necessidade de clínicos e microbiologistas permanecerem atentos à possibilidade de processos infecciosos nosocomiais serem ocasionados por Corynebacterium sp., particularmente por amostras multiresistentes aos antimicrobianos.

Over a five-year period, 163 strains of Corynebacterium sp. were recovered from different clinical specimens of patients from a Brazilian University hospital. Genitourinary tract and intravenous sites specimens were the most frequent sources of corynebacteria (46.62%). Corynebacterium amycolatum (29.55%), Corynebacterium minutissimum (20.45%) and Corynebacterium pseudodiphtheriticum (13.63%) were the predominant species found in genitourinary tract. C. minutissimum (24.14%) and Corynebacterium propinquum (17.24%) in surgical and/or other skin wounds and abscesses; Corynebacterium xerosis (25%), C. amycolatum (21.87%) and C. pseudodiphtheriticum (18.75%) in intravenous sites; C. pseudodiphtheriticum (33.33%) and C. propinquum (33.33%) in lower respiratory tract. Microorganisms were all susceptible to vancomycin and most of the species was predominantly resistant to beta-lactams. Antimicrobial susceptibility patterns of corynebacteria were not predictable. Multiple antibiotic resistance observed in C. jeikeium was also found among C. xerosis, C. minutissimum, C. afermentans, C. propinquum, C. amycolatum and C. pseudodiphtheriticum strains. Data suggest awareness of clinicians and microbiologists to nosocomial infections especially due to antimicrobial multiresistant strains of Corynebacterium sp.

Um caso de difteria ocorreu, em 1999, em mulher de 32 anos de idade. A paciente iniciou episódio de dor de garganta imediatamente após participação em reunião com profissionais europeus durante cinco dias consecutivos, no Rio de Janeiro. Ela declarou ter sido submetida ao esquema completo de imunização contra difteria (DTP-tríplice bacteriana) na infância e a doses de reforço (dT-dupla adulto) há dois anos. O diagnóstico clínico da doença só foi firmado após o laboratório de microbiologia ter confirmado a capacidade de produção de toxina pela amostra isolada de Corynebacterium diphtheriae var. gravis, biotipo não fermentador de sacarose comumente encontrado em diversos países europeus e responsável pela atual epidemia na região correspondente a antiga União Soviética. Na era da vacinação antidiftérica, indivíduos adultos de nossa comunidade podem apresentar-se potencialmente susceptíveis a difteria.

In 1999, a case of diphtheria in a 32-year-old woman was reported. The patient developed a sore throat immediately after participating of a five-day meeting with European workers in Rio de Janeiro. Her history included complete pediatric immunization (DTP) and three doses of adult formulation tetanus and diphtheria toxoid (dT) two years earlier. Clinical diagnosis of diphtheria was not made until microbiologic examination of specimens confirmed toxigenicity of Corynebacterium diphtheriae var. gravis, a biotype currently found circulating within Europe where diphtheria remains epidemic. This case reinforces the potential susceptibility of Brazilian adults to epidemic diphtheria in the vaccine era.