RESUMO
Neonatal sepsis leads to severe morbidity and occasionally death among neonates within the first week following birth, particularly in low- and middle-income countries. Empirical therapy includes antibiotics recommended by WHO. However, these have been ineffective against antimicrobial multidrug-resistant bacterial strains such as Klebsiella spp, Escherichia coli, and Staphylococcus aureus species. To counter this problem, new molecules and alternative sources of compounds with antibacterial activity are sought as options. Actinobacteria, particularly pathogenic strains, have revealed a biotechnological potential still underexplored. This study aimed to determine the presence of biosynthetic gene clusters and the antimicrobial activity of actinobacterial strains isolated from clinical cases against multidrug-resistant bacteria implicated in neonatal sepsis. In total, 15 strains isolated from clinical cases of actinomycetoma were used. PCR screening for the PKS-I, PKS-II, NRPS-I, and NRPS-II biosynthetic systems determined their secondary metabolite-producing potential. The strains were subsequently assayed for antimicrobial activity by the perpendicular cross streak method against Escherichia fergusonii Sec 23, Klebsiella pneumoniae subsp. pneumoniae H1064, Klebsiella variicola H776, Klebsiella oxytoca H793, and Klebsiella pneumoniae subsp. ozaenae H7595, previously classified as multidrug-resistant. Finally, the strains were identified by 16S rRNA gene sequence analysis. It was found that 100% of the actinobacteria had biosynthetic systems. The most frequent biosynthetic system was NRPS-I (100%), and the most frequent combination was NRPS-I and PKS-II (27%). All 15 strains showed antimicrobial activity. The strain with the highest antimicrobial activity was Streptomyces albus 94.1572, as it inhibited the growth of the five multidrug-resistant bacteria evaluated.
Assuntos
Antibacterianos , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Sepse Neonatal , Nocardia , Streptomyces , Antibacterianos/farmacologia , Humanos , Recém-Nascido , Sepse Neonatal/microbiologia , Nocardia/efeitos dos fármacos , Nocardia/genética , Nocardia/isolamento & purificação , Streptomyces/genética , Klebsiella/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Escherichia/efeitos dos fármacos , Reação em Cadeia da PolimeraseRESUMO
INTRODUCTION: Mycetoma is a chronic granulomatous inflammatory disease of the subcutaneous tissue, which affects deep structures and bone. Most cases of actinomycetoma are caused by members of the genus Nocardia. CASE PRESENTATION: Here we report the case of a 43-year-old male who presented a disseminated mycetoma on the forearm, chest and neck, characterized by enlarged and erythematous lesions through which seropurulent material drains, and numerous atrophic scars. Molecular identification was performed by 16S gene amplification and sequencing. Nocardia mexicana was identified with 100% identity. Trimethoprim-sulfamethoxazole, diaminodiphenyl sulfone and amikacin was a successful treatment after 6 months. CONCLUSIONS: Nocardia mexicana is a rare organism that causes mycetoma. We report a case of extensive mycetoma on the forearm with spread to the neck and thorax associated with manipulation of the mouth of a calf.
Assuntos
Antibacterianos , Antebraço , Micetoma , Pescoço , Nocardiose , Nocardia , RNA Ribossômico 16S , Tórax , Humanos , Masculino , Adulto , Nocardia/isolamento & purificação , Nocardia/genética , Micetoma/microbiologia , Micetoma/tratamento farmacológico , Micetoma/diagnóstico , Nocardiose/microbiologia , Nocardiose/tratamento farmacológico , Nocardiose/diagnóstico , Antebraço/microbiologia , Antebraço/patologia , Tórax/diagnóstico por imagem , Tórax/microbiologia , Pescoço/patologia , Antibacterianos/uso terapêutico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Resultado do Tratamento , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Amicacina/uso terapêutico , DNA Ribossômico/genética , DNA Ribossômico/químicaRESUMO
The coinfections by some microorganisms have been related to severe diseases in humans and animals, where immunosuppressive agents favor opportunistic behavior of other pathogens. A 4-month-old, female mixed-breed dog with a two-week history of inappetence, prostration, emaciation, and respiratory distress was admitted at a veterinary hospital in Brazil. Tachycardia, pale mucous membranes, severe respiratory distress, and a large number of ticks (Rhipicephalus sanguineus s.l.) in different body regions were observed at clinical examination. Hematological examination of dog showed leukocytosis, neutrophilia, mild anemia, and thrombocytopenia, whereas unremarkable values in biochemical tests. Thoracic radiography revealed a pleural effusion image. Blood and the pleural fluid (purulent aspect) samples were subjected to qPCR (16S rRNA and dsb genes) and sequencing, which identified Ehrlichia canis and Anaplasma platys coinfection. An aggregate of coccoid-to-branching or long filamentous microorganisms, surrounded by pyogranulomatous inflammatory reaction was seen at the cytology of the pleural fluid. Bacteriological culture of pleural effusion showed colonies compatible with the genus Nocardia, which revealed gram-positive filamentous organisms with a tendency of fragmentation and were identified as Nocardia otitidiscaviarum in mass spectrometry (MALDI-TOF MS). Therapy of N. otitidiscaviarum isolate using levofloxacin (supported by a previous in vitro susceptibility testing) and doxycycline for E. canis and A. platys resulted in complete resolution of the clinical picture. Here, we report for the first time a triple coinfection by Nocardia otitidiscaviarum, A. platys, and E. canis in a dog with pleural effusion, where debilitating or immunosuppressive conditions induced by A. platys and E. canis coinfection probably contributed to the opportunistic behavior of N. otitidiscaviarum.
Assuntos
Anaplasmose , Coinfecção , Doenças do Cão , Ehrlichiose , Nocardia , Derrame Pleural , Síndrome do Desconforto Respiratório , Humanos , Cães , Feminino , Animais , Lactente , Ehrlichia canis/genética , Anaplasmose/microbiologia , Coinfecção/veterinária , Coinfecção/microbiologia , Ehrlichiose/veterinária , Ehrlichiose/microbiologia , RNA Ribossômico 16S/genética , Nocardia/genética , Derrame Pleural/veterinária , Doenças do Cão/microbiologiaRESUMO
Mycetoma is a neglected tropical disease (NTD) declared by the World Health Organization (WHO) in 2016. It is characterized by the progressive growth of nodules and granulomatous lesions on the legs, arms, and trunk. It is potentially disfiguring and causes disability or amputations in working-age people from marginalized areas. The causative agents can be fungi (eumycetoma) or actinobacteria (actinomycetoma), the latter being the most common in America and Asia. Nocardia brasiliensis is the most important causal agent of actinomycetoma in the Americas. Taxonomic problems have been reported when identifying this species, so this study aimed to detect the 16S rRNA gene variations in N. brasiliensis strains using an in silico enzymatic restriction technique. The study included strains from clinical cases of actinomycetoma in Mexico, isolated from humans and previously identified as N. brasiliensis by traditional methods. The strains were characterized microscopically and macroscopically, then subjected to DNA extraction and amplification of the 16S rRNA gene by PCR. The amplification products were sequenced, and consensus sequences were constructed and used for genetic identification and in silico restriction enzyme analysis with the New England BioLabs® NEBcutter program. All study strains were molecularly identified as N. brasiliensis; however, in silico restriction analysis detected a diversity in the restriction patterns that were finally grouped and subclassified into 7 ribotypes. This finding confirms the existence of subgroups within N. brasiliensis. The results support the need to consider N. brasiliensis as a complex species.
Assuntos
Micetoma , Nocardiose , Nocardia , Humanos , Micetoma/diagnóstico , Micetoma/genética , Micetoma/microbiologia , RNA Ribossômico 16S/genética , América Latina , Genes de RNAr , Nocardia/genética , Região do Caribe , Nocardiose/genética , Nocardiose/microbiologiaRESUMO
Between August and December 2013, the offshore cages of a commercial marine farm culturing red drum Sciaenops ocellatus in Campeche Bay Mexico were affected by an outbreak of an ulcerative granulomatous disease with up to 70% cumulative mortality. Thirty-one adults displaying open ulcers on the skin were submitted for diagnosis. At necropsy, multiple white-yellowish nodules (0.1-0.5 cm in diameter) were present in all internal organs, where the kidney and the spleen were the most severely affected. Histopathology evinced typical systemic granulomatous formations. Gram and Ziehl-Neelsen stains on tissue imprints, bacterial swabs and tissue sections revealed Gram-positive, acid-fast, branching beaded long rod filamentous bacteria. Tissue samples resulted positive for nocardiosis with a Nocardia genus-specific nested PCR. Definite identification at the species level and taxonomic positioning of the fastidious pathogen were achieved through a specific Nocardia seriolae PCR and by sequencing the gyrB gene of pure isolates. After administration of antibiotics during fry production, a posterior follow-up monitoring (from 2014 to 2017) detected mild but recurrent outbreaks of the bacteria with no seasonality pattern. To the extent of our knowledge, this is the first report of piscine nocardiosis in Mexico and the first time this disease is detected in red drum.
Assuntos
Doenças dos Peixes/diagnóstico , Peixes , Nocardiose/veterinária , Nocardia/isolamento & purificação , Animais , Doenças dos Peixes/microbiologia , México , Nocardia/classificação , Nocardia/genética , Nocardiose/diagnóstico , Nocardiose/microbiologiaRESUMO
Cutaneous nocardiosis is a skin disease mainly caused by Nocardia brasiliensis and Nocardia asteroides. Here, we report a rare case of lymphocutaneous dermatosis in an 87-year-old Chinese man infected with Nocardia brasiliensis. An 87-year-old Chinese man presented at our hospital after suffering erythema, nodules, abscesses, ulceration, and pain in the left upper limb for 10 days. The patient was initially misdiagnosed as lymphocutaneous sporotrichosis. The results of gram staining, acid-fast staining, mass spectrograph revealed Nocardia brasiliensis and 16S ribosomal RNA (16S rRNA) sequencing of samples showed that the patient had a Nocardia brasiliensis infection. Anti-infective therapy with sulfamethoxazole combined with amoxicillin clavulanate potassium was administered for 10 days, followed by sulfamethoxazole alone for 20 days. After 30 days of treatment, the abscess was treated with repeated pus extraction, debridement of erosion and ulcer, wet compress of povidone iodine solution and spectrum of multi-source instrument. The redness and swelling had subsided, and purulent secretion and ulceration had decreased. Lymphocutaneous nocardiosis can easily be misdiagnosed as sporotrichosis based on its clinical manifestations. However, mass spectrometry analysis showed Nocardia brasiliensis according to the fingerprint of the bacteria and 16S rRNA sequencing to identify bacterial DNA can assist with making a diagnosis. For patients with Nocardia brasiliensis, sulfamethoxazole combined with amoxicillin clavulanate potassium is an effective anti-infective treatment.
Assuntos
Nocardiose , Nocardia , Dermatopatias Bacterianas , Idoso de 80 Anos ou mais , Humanos , Masculino , Nocardia/genética , Nocardiose/diagnóstico , Nocardiose/tratamento farmacológico , RNA Ribossômico 16S/genética , Dermatopatias Bacterianas/diagnóstico , Dermatopatias Bacterianas/tratamento farmacológicoRESUMO
PURPOSE: To report a case of Nocardia farcinica keratitis in a pediatric contact lens wearer. METHODS: Case report and literature review. RESULTS: A pediatric contact lens wearer was initially misdiagnosed with a poorly healing corneal abrasion after swimming with his contact lenses. On examination at our center, he was found to have a 2.5 by 2.5 mm corneal infiltrate with feathery margins. Microbiology revealed N. farcinica keratitis, which was treated with topical amikacin. The patient returned to his baseline visual acuity after treatment. CONCLUSIONS: Nocardia keratitis can be misdiagnosed because of its low prevalence, especially in young patients. Prompt diagnosis is important for proper management in these cases. The infection resolved in our patient with prompt diagnosis and treatment with topical amikacin eye drops.
Assuntos
Lentes de Contato Hidrofílicas/microbiologia , Úlcera da Córnea/microbiologia , Infecções Oculares Bacterianas/microbiologia , Nocardiose/microbiologia , Nocardia/isolamento & purificação , Adolescente , Antibacterianos/uso terapêutico , Úlcera da Córnea/diagnóstico , Úlcera da Córnea/tratamento farmacológico , DNA Bacteriano/genética , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Moxifloxacina/uso terapêutico , Nocardia/genética , Nocardiose/diagnóstico , Nocardiose/tratamento farmacológico , RNA Ribossômico 16S/genética , Acuidade Visual/fisiologiaRESUMO
Here, we present a case of disseminated nocardiosis, involving pneumonia, percutaneous abscess, and bacteremia, in a 67-year-old Japanese woman. She had also been treated for rheumatoid arthritis with prednisolone, methotrexate, and tocilizumab (interleukin-6 receptor inhibitor). Based on the 16S rRNA sequence analysis and a blast search, we identified the isolate as Nocardia brasiliensis. We discontinued methotrexate and tocilizumab on admission, and administered intravenous antimicrobial combination therapy for 6 weeks, followed by oral trimethoprim-sulfamethoxazole for 12 months, in total. Nocardia bacteremia is rare, often difficult to diagnose, and substantially fatal. However, due to our prompt diagnosis within one day of the onset of symptoms, and administration of appropriate treatment based on antimicrobial susceptibilities, this patient succeeded in surviving the infection. Not only microbiologists but also clinicians should be aware of the characteristic bacterial form of Gram/Kinyoun staining for early recognition of nocardiosis.
Assuntos
Antibacterianos/uso terapêutico , Anticorpos Monoclonais Humanizados/efeitos adversos , Bacteriemia/diagnóstico , Nocardiose/diagnóstico , Nocardia/isolamento & purificação , Idoso , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/imunologia , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , DNA Bacteriano/isolamento & purificação , Quimioterapia Combinada/métodos , Feminino , Violeta Genciana , Humanos , Nocardia/genética , Nocardiose/tratamento farmacológico , Nocardiose/microbiologia , Fenazinas , RNA Ribossômico 16S/genética , Resultado do TratamentoRESUMO
BACKGROUND: We report a case of a primary cutaneous nocardiosis by autochthonous Nocardia brasiliensis in a Spanish immunocompetent 9-year-old boy. METHODS: N. brasiliensis caused cellulitis showing the patient recovery after drainage and treatment with trimethoprim-sulfamethoxazole. Nocardia grew in pure culture and its identification was confirmed by sequencing (16S rRNA) and by MALDI-TOF MS (Bruker, Daltonics, Germany). CONCLUSIONS: In Spain although N. brasiliensis cutaneous infections in children are very infrequent should not be ruled out when an insect bite, stuck with a pine needle or an animal scratch has existed and the wound evolution is torpid.
Assuntos
Drenagem/métodos , Nocardiose/terapia , Nocardia/efeitos dos fármacos , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Antibacterianos/uso terapêutico , Criança , Humanos , Masculino , Nocardia/genética , Nocardia/isolamento & purificação , Nocardiose/microbiologia , RNA Ribossômico 16S/genética , Espanha , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
This study aims at genetic characterization and phylogenetic relationships of Nocardia brasiliensis focusing by using housekeeping rrs, hsp65, and sodA genes. N. brasiliensis is the species responsible for 80% of cases of actinomycetoma, one form of cutaneous nocardiosis which occurs mainly in tropical regions reaching immunocompetent patients in which the disease can lead to amputation. We analyze 36 indigenous cases of N. brasiliensis that happened in France. Phylogenetic analysis targeting rrs gene showed no robustness at phylogenetic nodes level. However, the use of a concatenation of hsp65 and sodA genes showed that the tested strains surprisingly ranked in 3 well-defined genotypes. Genotypes 2 and 3 were phylogenetically closer to each other and both diverged from genotype 1 sustained by a high bootstrap of 81%. This last genotype hosts all the cases of pulmonary forms (3), the sole cerebral form, and almost all the cases of immunocompromised patients (3 out of 4). Moreover, excepting one of them, all the strains belonging to this group present a susceptibility to imipenem which is not the case in the other genotypes that rarely count among them strains being susceptible to this drug. The haplotype diversity (Hd) of hsp65 (0.927) and sodA (0.885) genes was higher than that of rrs (0.824). For this gene, we obtained 16 polymorphic sites whereas, for hsp65 and sodA genes, up to 27 and 29 were identified, respectively. This study reveals that these two genes have an important genetic discriminatory power for the evaluation of the intraspecies genetic variability of N. brasiliensis and they may be useful for identification purposes at species level. This study also reveals the possible existence of a new species harbored by genotype 1.