PubMed HealthSearch

Biomedical subjects

P G Shivananda

Publications and source records attributed to P G Shivananda.

At least 19 recordsLinked to original sources

Effect of trace metals on synthesis of exoproteins and exotoxins by Staphylococcus aureus.

Staphylococcus aureus did not grow in chemically defined medium completely free of trace metals. At low concentrations all the trace metals showed stimulating effect on growth and exoprotein production. Increasing concentrations of Ca2+ and Mg2+ were growth stimulatory whereas Co2+, Cu2+, Fe3+, Mn2+, Ni2+ and Zn2+ were inhibitory. The amount of exoprotein and haemolytic exotoxins produced in relation to final viable count increased with increasing concentrations of growth inhibitory trace metals whereas it decreased with increasing concentrations of Ca2+ and Mg2+. Trace metals did not show significant influence on amount of haemolytic exotoxins produced in relation to total exoproteins. The results indicate presence of a common regulatory mechanism for all types of exoproteins produced by S. aureus.

Bacterial Proteins

Fungal colonization in gastric ulcers.

Until now studies on fungal colonization of gastric ulcers were retrospective involving small series of patients. This prospective study of 50 patients with gastric ulcers (25 benign and 25 malignant) revealed colonization by Candida in 17 (34%) cases. There was no significant difference in colonization between benign and malignant ulcers. Follow up revealed no difference in healing of ulcers with or without fungal colonization.

Adult

Bacteriological study of bronchoalveolar lavage in immunocompromised hosts.

Sixty bronchoalveolar lavage samples collected from lung cancer patients attending the Pulmonary Tuberculosis and Chest Diseases Unit of the Kasturba Medical College Hospital, Manipal; were cultured for both the aerobic and anaerobic organisms. Fifty nine samples yielded bacteria in pure culture. Pseudomonas aeruginosa (34.8%) was the commonest aerobe, Peptostreptococcus was the commonest anaerobe (45.2%) isolated. Bacteroides fragilis was isolated in (23.8%) of cases. Gentamycin was found to be effective against aerobes, Metronidazole and Rifampicin against anaerobes.

Bacteria, Aerobic

Correlation of phospholipase A & enterotoxin production by Salmonella typhimurium with reference to virulence parameters.

Seventy strains of S. typhimurium along with 10 strains each of S. typhi and S. paratyphi B, 3 strains of S. enteritidis and 2 strains of S. senftenberg were examined for phospholipase A (PLA) activity. S. typhimurium positive for PLA activity (17.14%) were subjected to study of other virulence parameters like enterotoxin production, haemolytic activity, surface hydrophobicity and antibiotic sensitivity. A high degree of correlation was observed between PLA activity and enterotoxin production, antibiotic sensitivity and cell surface hydrophobicity respectively.

Child, Preschool

Effect of trace metals on production of exoprotein and beta-lactamase by Staphylococcus aureus.

A minimum concentration of 0.01 mM of Mg2+ was essential for any growth of S. aureus. Of the trace metals, Mg2+ and Ca2+ were highly stimulatory for growth. All trace metals except Ni2+ in small concentrations were stimulatory for growth and exoprotein production. Amounts of exoprotein and beta-lactamase produced relative to the number of viable cells were maximum during the period of suboptimal proliferation of bacteria. Trace metals did not significantly influence the amount of beta-lactamase produced relative to exoprotein.

Bacterial Proteins

Invasive maxillary aspergillosis in an otherwise healthy individual.

Invasive aspergillosis is usually seen in immunocompromised individuals. We report the case of a 56-year-old immunocompetent housewife with Aspergillus niger invading the ethmoid and sphenoid sinuses and extending to the anterior cranial fossa. A. niger grew on three occasions (from the biopsy, mass and dura mater). In spite of medial maxillectomy and ethmoidectomy followed by craniofacial resection and antifungal drugs (amphotericin B) the patient died on tenth post-operative day.

Aspergillosis

Effect of magnesium on the physiology of Staphylococcus aureus.

The role of magnesium (Mg2+) in the metabolism of Staphylococcus aureus was studied using a chemically defined medium. At least 0.01 mM Mg2+ was required for any growth of S. aureus. Increasing concentration of Mg2+ up to 1.6mM steadily increased the bacterial growth. Glucose utilisation and acid production were also influenced by Mg2+. Excessive cobalt (Co2+) and zinc (Zn2+) were inhibitory to S. aureus growth and Mg2+ could reverse the inhibitory effect.

Cobalt

Rapid identification of Salmonella typhimurium in stools by using 4-methylumbelliferone derivatives.

A total of 150 stool samples were collected from the Paediatric ward and screened for the presence of Salmonella typhimurium. A comparison of standard biochemical tests and rapid fluorescence method was done. The fluorescence method was found to be rapid, less time consuming and easy to perform whereas identification of Salmonella typhimurium using standard biochemical tests taken 18 to 24 hours.

Child

Molds in onychomycosis.

BACKGROUND: Onychomycosis is a major cause of nail dystrophy. The causative organisms in onychomycosis are dermatophytes, Candida and molds. A variety of molds have been isolated from nails. METHODS: Nail scrapings and clippings were collected from 100 cases and inoculated on slants containing SDA with cycloheximide 0.5 mg/mL, chloramphenicol 0.05 mg/mL, and SDA with chloramphenicol 0.05 mg/mL. RESULTS: The culture positivity rate for molds was 22%. The predominant mold isolates were Aspergillus species (86.4%, Fusarium oxysporum (4.5%), Curvularia species (4.5%) and Penicillium species (4.5%). CONCLUSION: Primary invasion of nails by molds can cause onychomycosis.

Female

Acinetobacter sepsis in neonates.

Twenty-six neonates were diagnosed to have acinetobacter sepsis during 1986-90, representing 6.5% of all cases of bacteriologically proven sepsis. Of these 19 neonates were low birth weight (LBW) 12 were small for gestational age (SGA). Nineteen neonates had early-onset sepsis. The male to female ratio was 9:17. The hematological profile was suggestive of sepsis in 17 cases. All infants had clinical evidence of multi system infection. Eleven babies died; the cases-fatality rate was 42.3%. Only 15/25 culture isolates were sensitive to gentamicin and resistance to other antibiotics was even more frequent. Acinetobacter was cultured from other sites: eye swabs, skin pustules and umbilical catheter tips. Environmental nursery surveillance cultures done during the study period yielded Acinetobacter once from a crib, but no cases of sepsis occurred around that time. The epidemiological features of this organism illustrate the value of vigilance and precautionary measures.

Acinetobacter

A modified chemically defined medium for Staphylococcus aureus.

A chemically defined medium has been described which supported good growth of S. aureus. Optimal production of different exoproteins, viz. coagulase, acid phosphatase, proteinase, lipase, beta-lactamase and alpha-toxin was recorded in the medium.

Bacterial Proteins

Bacteriology of peritoneal fluid in paediatric surgical emergencies.

This study deals with the incidence of aerobic and anaerobic organisms of the peritoneal fluid of 60 consecutive children subjected to emergency celiotomy. Two-thirds of the cases were below the age of year. Peritoneal fluid was collected immediately after entering the peritoneal cavity and inoculated both for aerobic an anaerobic cultures. Bacterial growth occurred in 34 (57%) of the specimens. Anaerobic bacteria alone grew in 3 (5%) of the specimens, aerobes alone in 22 (37%) of specimens. A mixed aerobic and anaerobic bacteria grew in 9 (15%) of the specimens. There were 44 aerobic and 19 anaerobic isolates. All anaerobes were sensitive to metronidazole while most of the aerobes were sensitive to gentamycin. Culture was positive in 20 out of 42 (47.6%) specimens, where the peritoneal fluid was clear and there was no evidence of peritoneal contamination at the time of surgery.

Abdomen

Bacteriology of bile in obstructive jaundice.

Bile from 25 patients with obstructive jaundice was cultured for both aerobic and anaerobic organisms. Twenty one samples were positive for culture. Mixed bacterial growth was seen in 5 (20%) of the bile samples 25 aerobes and one anaerobic were isolated. Escherichia coli was the commonest aerobic isolate and Bacteroides fragilis was the single anaerobe isolated. Majority of the aerobes isolated were sensitive to gentamycin.

Bacteria, Aerobic