Cases of N. farcinica infections are being reported increasingly because of recent changes in taxonomy and diagnostic methodology. This change in epidemiology has implications for therapy because of the organism's pathogenicity and natural resistance to multiple antimicrobial agents, including third-generation cephalosporins. Any delay in starting appropriate antibiotic therapy can have adverse consequences.

We describe a case of bacteraemia caused by Weissella confusa in a 48-year-old male who was operated on for adenocarcinoma of the gastro-oesophageal junction and maintained on total parenteral nutrition. Blood cultures were positive for a vancomycin-resistant streptococcus-like organism which was identified as W. confusa by 16S rRNA gene sequencing.

A marine actinomycete Streptomyces rubrolavendulae M56 isolated from the sediments of Bay of Bengal and displaying biogranulation property was used for the study. The strain showed antagonistic property against vibrios, the opportunistic pathogens in aquaculture. The efficacy of the biogranules of actinomycete M56 in competitive exclusion of Vibrio spp. was tested both in vitro and in vivo. Streptomyces rubrolavendulae M56 biogranules could significantly exclude the pathogenic Vibrio spp. in co-culture experiments (in vitro). In vivo exclusion of Vibrio spp. in a Penaeus monodon postlarval rearing system was evaluated by treatment of the rearing water with biogranules of S. rubrolavendulae M56. The experiments proved that S. rubrolavendulae M56 biogranules could reduce the pathogenic Vibrio spp., while maintaining total heterotrophic bacterial count. Therefore, the actinomycete biogranules (M56) can be used as a promising alternative to antibiotics in the shrimp larval production system which is often affected by vibriosis.

Coryneform bacteria belonging to the genus Brevibacterium have emerged as opportunistic pathogens. Of the nine known species of Brevibacterium isolated from human clinical samples, Brevibacterium casei is the most frequently reported species from clinical specimens. We report the first case of B. casei brain abscess in an immunocompetent patient successfully treated by surgery and antimicrobial therapy. CASE REPORTA 31-year-old man was hospitalized for recurrent right-sided focal seizures with loss of consciousness for the last 3 months. The seizures were preceded by auras in the form of vomiting and paresthesia of the right upper and lower limbs. On admission, he complained of a bifrontal headache but was fully alert with normal vital signs, including temperature. Motor system examination revealed normal tone and bulk with power grade V in all groups. Deep tendon reflex was brisk bilateral with bilateral flexor plantar and numbness present in the right lower limb. The patient had received antituberculous chemotherapy (isoniazid, 300 mg; rifampin, 450 mg; ethambutol, 800 mg; and pyrazinamide, 1,500 mg) for the last 3 months as the brain lesion was misdiagnosed as tuberculoma at a local hospital based on the imaging. Magnetic resonance imaging (MRI) revealed a dark ring enhancing lesion measuring 1.2 by 0.7 cm in the left post-central gyrus with a central mural nodules and disproportionate white matter perilesional edema (Fig. 1). Magnetic resonance spectroscopy revealed elevated lipids/lactates suggestive of infective etiology. Lab workup revealed microcytic hypochromic anemia (4.8 ϫ 10 6 erythrocytes/mm 3 ), 5,500 white cells/l (70% polymorphonuclear cells), 218,000 platelets/l, and a 1-h erythrocyte sedimentation rate of 22 mm. Other laboratory findings were unremarkable. An initial diagnosis of brain abscess of infective etiology was made, and supportive care, including administration of mannitol and dexamethasone for control of cerebral edema, was started. He underwent left parasaggital craniotomy and excision of the abscess. During surgery, lesions identified on MRI were found to contain purulent material, which was completely drained and submitted for histopathology and microbiological analysis. The cytologic findings were consistent with necrotic abscesses, and direct Gram staining revealed a few Gram-positive bacilli.Smear and culture (MB/BacT ALERT 3D system) for acid-fast bacilli were negative.

Indiscriminate use of antibiotics has led to the emergence of antibiotic resistant microbes and the loss of natural flora in aquaculture systems ultimately necessitating the ban of many of the chemotherapeutants in aquaculture. Actinobacteria play a profound role in the biogeochemical cycling in the marine environment and they represent the principal source of secondary metabolites with antimicrobial property. In the present study, 98 marine derived actinomycete isolates were screened for antimicrobial activity against the common aquatic pathogens. A potent actinomycete isolate S26, identified as Streptomyces variabilis based on 16S rRNA gene sequencing was used for further study. Optimization of the fermentation medium for secondary metabolite production was carried out by response surface methodology (RSM) using DESIGN EXPERT. The ANOVA of the quadratic regression model demonstrated that the model was highly significant for the response concerned i.e., antimicrobial activity as evident from the Fisher’s F- test with a very low probability value [(P model>F) = 0.0001]. Of the 10 different solutions suggested by the software, the most suitable composition was found to be starch, 1.38 %; soy powder, 0.88 %; ammonium sulphate, 0.16 % and salinity, 27.76 ‰. S. variabilis S26 cultured in the optimized production medium was applied in the Penaeus monodon larval rearing system and the total Vibrio count and survival rate were estimated. S. variabilis S26 treatment showed a significant reduction in Vibrios and better survival in the Penaeus monodon culture system compared to the control.