Actividad antibacteriana de actinomicetos frente a Escherichia coli y Staphylococcus aureus multirresistentes de origen hospitalario / Antibacterial activity of actimycetes against multiresistant Escherichia coli and Staphylococcus aureus isolated from a hospital

Introducción: La resistencia a los antimicrobianos (RAM) es un problema de salud pública que manifiesta la disminuida eficacia de estos agentes en la prevención y tratamiento de una proporción cada vez más amplia de patologías. Los actinomicetos son un grupo bacteriano importante de productores de metabolitos activos contra patógenos. Objetivo: Aislar actinomicetos del bosque tropical de Nariño, con potencial producción de metabolitos inhibitorios contra bacterias multidrogo-resistentes. Materiales y métodos: Se tomaron muestras de suelo de Bosque Tropical Húmedo de la Reserva Natural del Río Ñambí, se analizaron microbiológica y molecularmente. Se estimuló la producción in vitro de metabolitos secundarios y evaluó el efecto inhibitorio de estos extractos contra las bacterias multidrogo-resistentes Escherichia coli y Staphylococcus aureus. Resultados: Se obtuvieron 11 aislados presuntivos, se confirmó que cuatro de ellos correspondieron al género Streptomyces sp. Las pruebas de inhibición contra bacterias multidrogo-resistentes E. coli y S. aureus, permitieron verificar que el aislado P3772 fue el más eficiente en la inhibición de los patógenos. Conclusiones: Todos los actinomicetos evaluados presentan actividad antibacteriana contra al menos una de las bacterias patógenas estudiadas; destacando el aislado P3772, que inhibe a E. coli y S. aureus. Se espera caracterizar los compuestos vinculados a la actividad antibacteriana.

Introduction: Antimicrobial resistance (AR) is a public health problem that reveals the diminished efficacy of these agents in the prevention and treatment of an increasingly larger number of pathologies. Actinomycetes are an important bacterial producer group of metabolites that are active against pathogens. Objective: To isolate actinomycetes from the tropical forest of Nariño (Colombia), which have the potential to produce inhibitory metabolites against multi-drug resistant bacteria. Materials and methods: Soil samples were taken from the Humid Tropical Forest of the Río Ńambí Natural Reserve and analyzed through microbiological and molecular assays. In vitro production of secondary metabolites was first stimulated, followed by the assessment of the inhibitory effect of these extracts against multi-drug resistant Escherichia coli and Staphylococcus aureus. Results: 11 presumptive isolates were obtained, confirming that four of them corresponded to the Streptomyces sp. genus. The bacterial isolate P3772 was identified as the one with the highest inhibitory effect against multi-drug resistant E. coli and S. aureus. Conclusions: All the actinomycetes evaluated presented antibacterial activity. The isolate P3772 stands out, which inhibited both E. coli and S. aureus. The compounds associated with this antibacterial activity will be characterized in future studies.

Granulomatous lobular mastitis: a clinicopathological analysis of 300 cases / 中华病理学杂志

Objective@#To investigate the clinicopathologic features and possible causes of granulomatous lobular mastitis(GLM).@*Methods@#Three hundred cases of GLM were collected from surgical specimens diagnosed at Longhua Hospital, Shanghai University of Traditional Chinese Medicine from January 2015 to November 2017. Morphologic features were reviewed using HE staining. A total of 116 cases were investigated by Gram staining. The expression of CD3, CD20, CD68, IgG, IgG4, CD38 and CD138 was detected by immunohistochemical staining.@*Results@#The age of the patients was 23 to 47 years and the median age was 32 years. All patients were female, 96.7% (290/300) had a history of lactation.There were 143 cases of left breasts, 138 cases of right breast and 19 cases of bilateral breasts. Serum prolactin increased in 39.7%(119/300) patients. Within 15.7%(47/300) of patients were associated with nodular erythema or joint swelling and pain of the lower extremities. Pathological observation showed that lobular-centric suppurative granulomatous inflammation, accompanied by dilatation of intralobular and interlobular ducts. There were 16 cases accompanied with duct ectasia. Immunohistochemistry showed CD3-positive lymphocytes were more than CD20-positive lymphocytes in the peripheral aggregation zone of neutrophils within granulomatous lesions. Gram positive bacteria were found in the lipid vacuoles of the 51.7%(60/116) patients.@*Conclusions@#GLM has distinctive histologic features. It may be related to corynebacterium infection, or accompanied by the increase of serum prolactin and erythrocyte sedimentation rate. The age, location and history of the disease are importance in the diagnosis and differential diagnosis.

Draft genome analysis of Dietzia sp. 111N12-1, isolated from the South China Sea with bioremediation activity

Abstract Dietzia sp. 111N12-1, isolated from the seawater of South China Sea, shows strong petroleum hydrocarbons degradation activity. Here, we report the draft sequence of approximately 3.7-Mbp genome of this strain. To the best of our knowledge, this is the first genome sequence of Dietzia strain isolated from the sea. The genome sequence may provide fundamental molecular information on elucidating the metabolic pathway of hydrocarbons degradation in this strain.

A Case of Chronic Gordonia otitidis Lung Infection Initially Regarded as Nontuberculous Mycobacterial Lung Disease / 대한임상미생물학회지

The genus Gordonia is one of the mycolic acid-containing aerobic actinomycetes. This genus has 38 named species that are widespread in the natural environment; however, Gordonia species rarely cause human infections. A 76-year-old woman presented with cough and sputum for over 1 year and was suspected of having nontuberculous mycobacterial (NTM) lung disease. An NTM isolate from the sputum was initially identified as Mycobacterium lentiflavum or Mycobacterium genavense by genotypic identification targeting internal transcribed spacer (ITS). However, the isolate was finally confirmed as Gordonia otitidis by sequencing of 16S rRNA, gyrB and secA1 genes. In patients with suspected NTM lung disease, the etiologic agent might be an organism other than NTM such as G. otitidis but still be identified as NTM without sequencing of 16S rRNA or other genes. Especially in case that a possible NTM isolate is identified as M. lentiflavum or M. genavense by the genotypic method targeting ITS, additional genotypic tests such as sequencing of 16S rRNA and other genes would be necessary for more reliable identification.

First Isolation of Segniliparus rugosus from a Patient with Radiologic Features Similar to Non-Tuberculous Mycobacteriosis / 결핵및호흡기질환

In 2005, a group of mycolic acid-containing bacteria was characterized as belonging to a novel genus, Segniliparus with species Segniliparus rugosus and S. rotundus. We report a case of the S. rugosus isolated from a 54-year-old woman with radiologic features mimicking that of non-tuberculous mycobacteriosis (NTM). When the patient first visited our hospital, an acid-fast bacteria (AFB) smear tested positive and Mycobacterium tuberculosis polymerase chain reaction (TB PCR) was negative in the bronchoalveolar lavage sample. After 2 months, the growing colonies were reported as NTM, but could not be identified because they had died. One year after the initial visit, induced sputum samples showed the same results, positive AFB smear and negative TB PCR. At this point, the growing colonies were identified as S. rugosus. Therefore, we should consider Segniliparus genus as a differential diagnosis for AFB in respiratory specimens in addition to the genus Mycobacterium.

Actinomicosis pulmonar Una enfermedad olvidada / Pulmonary actinomycosis A forgotten disease

La actinomicosis es una enfermedad causada por un microorganismo gram positivo anaerobio, Actinomyces israelií, habitualmente con ausencia de actividad patogénica. Su expresión infecciosa más común se localiza en piel de cara y cuello, dado que éste es residente frecuente de nariz y garganta. Su comportamiento infeccioso es raro en otros órganos. Se presenta un paciente adulto con cuadro clínico respiratorio de tres meses de evolución, en quien se diagnostica actinomicosis pulmonar posterior a lobectomía por sospecha clínica inicial de malignidad (Acta Med Colomb 2010; 35: 132-134).

Actinomycosis is a disease caused by Actinomyces israelii, a gram-positive, anaerobic microorganism which usually lacks pathogenic activity. Its most common clinical expression is infection of the skin of the face and neck, since the microorganism is a frequent resident of the nose and throat. Infectious behavior is extremely rare in other organs. We present the case of an adult patient with respiratory manifestations which evolved over a period of three months, who was diagnosed with Pulmonary Actinomycosis after lobectomy performed due to an initial clinical suspicion of malignancy (Acta Med Colomb 2010; 35: 132-134).