A prospective cross sectional study of detection of Clostridium difficile toxin in patients with antibiotic associated diarrhoea.

BACKGROUND AND OBJECTIVES: Clostridium difficile infections (CDI) include self-limiting antibiotic associated diarrhoea (AAD), antibiotic-associated colitis, and pseudomembranous colitis. The present study aimed at detecting C. difficile toxin in stool samples of patients with AAD and analyzing the antibiotic use and presence of other risk factors in these patients. MATERIALS AND METHODS: In this study, which was conducted on 660 samples, a 2- step strategy was used. In the first step, glutamate dehydrogenase (GDH) was detected in stool samples by enzyme-linked immunofluorescent assay (ELFA). In the second step, GDH positive samples were tested for C. difficile toxin A and B by ELFA. Nucleic acid amplification test (NAAT) was also performed on few samples that were found to be GDH positive and toxin negative or equivocal by ELFA. RESULTS: Of the 660 samples screened, toxin was detected in 8.8% (58/660) by ELFA and 9.7% (64/660) by NAAT. GDH was detected in 23.8% (157/660) and toxin in 36.9% (58/157) of the GDH positives. Most of the toxin positive patients were on one or more antibiotics prior to developing diarrhoea. The implicated antibiotics were meropenem, amikacin, colistin and cephalosporins. Diabetes, hypertension, use of proton pump inhibitors, previous hospitalization, malignancy and chemotherapy were found to be the risk factors in our study. CONCLUSION: Prevalence of GDH was 23.8% (157/660) by ELFA. Toxin prevalence was 9.7% (64/660). Detection rates of C. difficile associated diarrhoea (CDAD) increased with inclusion of NAAT testing by ELFA.

Multiple cortical brain abscesses due to Listeria monocytogenes in an immunocompetent patient.

Listeria monocytogenes is an intracellular organism which is well recognised for its ability to cause meningeal infections in neonates, immunosuppressed, debilitated and elderly individuals. 1 Other less common central nervous system (CNS) infections caused by Listeria spp. include rhomboencephalitis, cerebritis and abscesses in the brain, brain stem and spinal cord. The neuroradiological appearance of Listeria brain abscesses is similar to other types and may also mimic primary or metastatic brain tumours. 2 , 3 We report a case of Listeria brain abscesses in a patient who was being treated for atypical parkinsonism. A good clinical outcome was achieved after appropriate antimicrobial therapy.

Antimicrobial susceptibility profile, treatment outcome and serotype distribution of clinical isolates of Salmonella enterica subspecies enterica: a 2-year study from Kerala, South India.

BACKGROUND/PURPOSE: Typhoid and paratyphoid fever continue to be important causes of illness and death in parts of Asia, being associated with poor sanitation and consumption of unsafe food and water. Antimicrobial resistance has emerged to traditional first-line drugs, namely, the fluoroquinolones, as well as to third-generation cephalosporins, posing challenges to treatment. Azithromycin has proven to be an effective alternative for treatment of uncomplicated typhoid fever. The purpose of this study was to determine the antimicrobial susceptibility, clinical outcome and serotype distribution pattern of clinical isolates belonging to Salmonella enterica subspecies enterica. METHODOLOGY: All clinical isolates of S. enterica obtained from blood, sterile body fluids, as well as stool and urine samples at Amrita Institute of Medical Sciences and Research Centre, Kerala, India, between August 2011 and July 2013 were included in the study and processed based on standard microbiology protocols. RESULTS: A total of 118 isolates of Salmonella were obtained during the study period. Out of these, 79 were of S. Typhi (66.95%), followed by isolates of S. Paratyphi A (22; 18.64%) and S. Typhimurium 12 (10.17%). Five isolates could not be identified further. There was 100% susceptibility to ceftriaxone in all S. enterica subspecies. Ciprofloxacin susceptibility was 32.91% for S. Typhi and 40.90% for S. Paratyphi A as determined by the disk diffusion method. The susceptibility profile of S. Typhi isolates to different antimicrobials was as follows: chloramphenicol (94.93%), ampicillin (77.21%), cotrimoxazole (75.94%) and azithromycin (78.48%). For S. Typhi, the minimum inhibitory concentration (MIC) of ciprofloxacin required to inhibit the growth of 50% of organisms was 0.5 µg/mL (intermediate) and MIC required to inhibit the growth of 90% of organisms was 1 µg/mL (resistant). S. Typhimurium was 100% susceptible to cotrimoxazole, ampicillin, ceftriaxone, chloramphenicol, ofloxacin and azithromycin. Susceptibility to ciprofloxacin was 66.66%. Patients from whom S. Typhimurium was isolated had comorbidities with documented risk. Of the 118 patients, 3 expired. Two had typhoid fever and were in sepsis at admission. One had S. Typhimurium and was suffering from multiple myeloma. CONCLUSION: S. Typhi was the predominant isolate. All isolates were susceptible to ceftriaxone. Chloramphenicol susceptibility was >90%. No multidrug-resistant Salmonella strains were isolated. Susceptibility to ciprofloxacin for S. Typhi was 33%. Recovery rate was 97%.

Salmonella Typhimurium pneumonia in a patient with multiple myeloma.

Pneumonia due to non-typhoidal Salmonella is a rarely reported entity. A fatal case of Salmonella pneumonia is reported here where Salmonella Typhimurium was isolated from the endotracheal aspirate and blood culture.

Post-operative endophthalmitis due to Fusarium dimerum.

Fungal endophthalmitis is a destructive intraocular infection resulting in poor visual prognosis. Endophthalmitis due to Fusarium spp has the worst visual prognosis. We report a case of a 58-year-old female patient who underwent cataract extraction and intraocular lens implantation in the right eye and presented two months after the surgery with fungal endophthalmitis. The aqueous humor culture grew Fusarium dimerum. The patient was treated with intravitreal and oral voriconazole and topical prednisolone. The patient experienced one episode of recurrence following by remarkable improvement. To our knowledge, this is the first reported case of Fusarium dimerum endophthalmitis.

Brevibacterium casei as a cause of brain abscess in an immunocompetent patient.

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.

Anti-infective properties of Lactobacillus fermentum against Staphylococcus aureus and Pseudomonas aeruginosa.

Surgical wounds and implant-associated Staphylococcus aureus and Pseudomonas aeruginosa infections are often difficult to treat because of limited susceptibility of several of these strains to conventional antibiotics. As a result, there is a constant need for new alternative drugs. The aim of this study was to investigate the antimicrobial properties of Lactobacillus fermentum, a probiotic bacterium, which we have isolated from colonic biopsies. The inhibition of S. aureus and P. aeruginosa growth was evaluated by coincubating with L. fermentum strains. Growth inhibition was tested for several of their clinical isolates using agar well diffusion assays. For biofilm assay S. aureus and P. aeruginosa were grown on the glass slides and in 96-well plates in presence of 2.5 µg/ml culture filtrate of L. fermentum. Biofilms were photographed using confocal microscope or stained with 0.1% crystal violet. Reduction in the cytotoxicity of S. aureus and P. aeruginosa was observed in presence of 2.5 µg/ml L. fermentum-spent media. Using in vitroexperiments, we showed that L. fermentum-secreted compound(s) inhibits the growth, cytotoxicity and biofilm formation of several S. aureus and P. aeruginosa strains. Compound(s) present in the culture supernatant of L. fermentum may have promising applications in treating hospital-acquired infections.

Weissella confusa: a rare cause of vancomycin-resistant Gram-positive bacteraemia.

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.

Lactobacillus fermentum isolated from human colonic mucosal biopsy inhibits the growth and adhesion of enteric and foodborne pathogens.

A number of Lactobacillus species are used as probiotic strains in order to benefit health. We have isolated L. fermentum from human colonic mucosal biopsy samples that possess antimicrobial activities against entroinvasive and foodborne pathogens such as Escherichia coli, Salmonella paratyphi A, Shigella sonnei, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa, and Vibrio sp. In addition to lactic acid, L. fermentum secretes antimicrobial proteinacious compound(s) that was found to be active even at neutral pH (pH 7.0). The compound was sensitive to heat treatment and trypsin digestion. Lactobacillus fermentum inhibited the adhesion of enteropathogens to intestinal epithelial cells in vitro. Isolated cell surface associated proteins (SAPs) from L. fermentum were sufficient for the adhesion exclusions of enteropathogenic E. coli. Our results indicate that L. fermentum produces antimicrobial compounds and SAPs to inhibit the growth and adhesion of enteropathogens, respectively.

Aerobic bacterial isolates from choledochal bile at a tertiary hospital.

We studied the aerobic bacterial isolates from bile and their susceptibilty pattern in patients with biliary tract disease. Samples of bile collected during endoscopic retrograde cholangio pancreatography (ERCP) and surgery, were inoculated on standard media. Bacterial identification and susceptibility were done by standard techniques. A total of 209 samples were cultured, out of which 128 samples showed growth. Total number of isolates obtained was 221. Poly-microbial infection was detected in 67 patients. Predominant aerobic bacterial isolates obtained were Escherichia coli 30% (67), Klebsiella species 23.98% (53), Enterococcus species 12.21% (27). Multi-drug resistance was noted in 57%. Higher resistance rate was noted among Gram negative bacilli for ampicillin (92.4%), cephalexin (82.46%), ciprofloxacin (68.42%), piperacillin (64.33%). Sensitivity to meropenem was 90.64% and amikacin was 76.61%. Gram positive bacteria showed high resistance to gentamicin (39.53%). Sensitivity to ampicillin was 86.05% and penicillin was 81.4%. Vancomycin and teicoplanin showed 100% sensitivity. From our study we conclude that E. coli, Klebsiella species and Enterococcus species are common pathogens infecting biliary tract. Poly-microbial infection and multi-drug resistance warrants culture and sensitivity to guide antimicrobial therapy. We recommend combination of amikacin and ampicillin for empirical therapy at our institution.