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Biomedical subjects

B A Cunha

Publications and source records attributed to B A Cunha.

At least 19 recordsLinked to original sources
PubMed1992

Differential effects of bismuth and salicylate salts on the antibiotic susceptibility of Pseudomonas aeruginosa.

The influence of salicylate or bismuth salts on antibiotic action against Pseudomonas aeruginosa was assessed in broth cultures. Sodium salicylate (2.5 mM) had no significant effect on the activity of any antibiotic tested. In contrast, bismuth compounds (0.5 mM) produced a significant change in the inhibitory activity of several antibiotics against all strains. Bismuth salts reduced imipenem activity by up to 20-fold, enhanced gentamicin or amikacin activity three to five-fold, and enhanced cefpirome or cefepime activity by as much as 10-fold against antibiotic-sensitive and resistant strains. Bismuth salts had little effect on cefoperazone, ceftazidime, or mezlocillin activity. Combining bismuth salts with aminoglycosides or fourth-generation cephalosporin antibiotics may help to combat the growing problem of resistant Pseudomonas aeruginosa.

Anti-Bacterial Agents↗
PubMed1992

Mycobacterium bovis vertebral osteomyelitis and psoas abscess after intravesical BCG therapy for bladder carcinoma.

Systemic complications of intravesicular BCG for bladder carcinoma are uncommon, and include fever, pneumonia, hepatitis, arthralgias, or skin rash. Local complications of BCG therapy for bladder cancer include cystitis, prostatitis, epididymo-orchitis, granulomatous lymphadenitis, or ureteral obstruction. We believe this is the first case of Mycobacterium bovis vertebral osteomyelitis and psoas abscess complicating intravesicular BCG therapy for bladder carcinoma.

Administration, Intravesical↗
PubMed1992

Aminopenicillins in urology.

The use of ampicillin and amoxicillin remains a mainstay of urologic prophylaxis and therapy, however ampicillin's effectiveness against aerobic gram-negative bacilli, especially Escherichia coli has steadily decreased over time due to increasing beta-lactamase-induced resistance. Presently, up to 40-60 percent of E. coli may be ampicillin resistant. Since there have been no major resistance problems with enterococci, ampicillin remains the preferred anti-enterococcal antibiotic in penicillin-tolerant patients. Ampicillin/beta-lactamase inhibitor combinations are preferred when penicillins are used to treat ampicillin resistant aerobic gram-negative bacillary urinary tract infections (UTIs). One response to the problem of resistance has been short-course or single-dose therapy for uncomplicated cystitis in immunocompetent adults, which is less likely to cause side effects, bacterial resistance, or alterations in bowel flora. Another response has been to combine the aminopenicillins with beta-lactamase inhibitors such as clavulanate or sulbactam.

Bacteria↗
PubMed1992

Flavimonas oryzihabitans (CDC group Ve-2) bacteraemia associated with Hickman catheters.

Flavimonas oryzihabitans is a potential pathogen that may infect patients who have major medical illnesses, especially those who are undergoing surgery or have indwelling venous catheters in situ. Flavimonas oryzihabitans has been isolated from a wide range of body sites, and the portals of entry are major wounds or implanted foreign materials. We report two cases of F. oryzihabitans bacteraemia associated with the use of Hickman catheters for administration of the patients' chemotherapeutic agents. However, a common source for these infections could not be demonstrated.

Bacteremia↗
PubMed1992

Sepsis associated with transhepatic cholangiography.

A retrospective study was carried out of 74 elderly patients with obstructive jaundice undergoing percutaneous transhepatic cholangiography (PTC) and/or percutaneous biliary drainage (PBD) in order to assess the effect of prophylactic antibiotics on the incidence of fever and sepsis complicating these procedures. Seventeen patients underwent PTC alone, while 57 had both PTC and PBD. Fifty-three patients had either primary or metastatic malignancy. In the other patients with benign disease, choledocholithiasis was the most common reason for undertaking these procedures. Prophylactic antibiotics were given in 80% of cholangiographies and 93% of biliary drainage procedures. There was an overall incidence of sepsis of 13.5%. Enterobacter cloacae and Acinetobacter anitratus were the most common blood culture isolates in patients with malignant biliary obstruction. The incidence of fever was no different between patients who underwent PTC alone compared with those who had PTC and PBD. Of 24 patients who developed fever, two died secondary to sepsis. Although there was no difference in the rate of sepsis and febrile episodes between the two groups, the risk of septic episodes and mortality emphasizes the need for antibiotic prophylaxis and early therapy in elderly patients undergoing percutaneous biliary drainage procedures.

Acinetobacter Infections↗
PubMed1992

Measles: lessons from an outbreak.

BACKGROUND: Measles outbreaks continue to be a problem for infection control in hospitals--patients, personnel, and employee health service. Guidelines for measles outbreaks are not clear for medical personnel in the hospital. METHODS: Outbreak investigation in a university-affiliated teaching hospital. RESULTS: Four primary cases resulted in 607 staff exposures and two secondary cases. Forty-seven medical personnel were furloughed and 88 were vaccinated for measles. Minimal serologic criteria for immunity were found to be inadequate in the outbreak setting. CONCLUSIONS: We found that serologic guidelines for assessing immunity to measles are inadequate. During the outbreak, we arbitrarily doubled the acceptable enzyme-linked immunosorbent assay titers that we would consider protective, > or = 2, to decrease the possibility of further secondary cases. Employees with enzyme-linked immunosorbent assay measles titers less than 2 and without a definite history of natural measles were revaccinated with a measles vaccine. This strategy takes advantage of the anamnestic response that revaccination would confer in persons with low antibody titer.

Adult↗
PubMed1992

Rapid plasmid DNA isolation from mucoid gram-negative bacteria.

Exopolysaccharides interfere with the isolation and characterization of plasmid DNA from gram-negative bacteria. To repress capsular polysaccharide production, bacteria were cultured in medium containing bismuth nitrate and sodium salicylate. Rapid removal of other contaminating bacterial surface components was achieved by mild acidic zwitterionic detergent extraction. After treatment, bacterial cells were more readily lysed in alkaline detergents. The resulting plasmid preparations contained virtually no capsular polysaccharide and relatively small quantities of lipopolysaccharide and protein, yet they produced yields of nucleic acids similar to those of conventional plasmid preparations. Conventional preparations from encapsulated organisms were largely insoluble and appeared as smears following agarose gel electrophoresis, with indefinite plasmid banding. Plasmids prepared by the new method were highly soluble in conventional buffers and exhibited high-resolution plasmid banding patterns in agarose gels. Plasmids as large as 180 kbp could be isolated and visualized, without apparent nicking, and were readily digested by restriction endonuclease enzymes. The method proved effective with encapsulated or mucoid strains of Klebsiella pneumoniae, Escherichia coli, Acinetobacter anitratus, Salmonella typhimurium, and Enterobacter species. The complete method for plasmid isolation was not suitable for Pseudomonas aeruginosa because of the inhibitory effects of bismuth. Thus, removal of contaminating bacterial surface structures enabled the rapid isolation and characterization of plasmids from mucoid clinical isolates, without the use of organic solvents, CsCl gradients, or expensive, disposable columns.

Bacterial Typing Techniques↗
PubMed1992

Postoperative Serratia marcescens endophthalmitis.

Endophthalmitis after ophthalmic surgery is a rare but serious complication. Postoperative endophthalmitis presents clinically with conjunctival erythema and lid edema with eye pain and decrease in visual acuity. Diagnosis requires invasive culture techniques because postoperative external eye cultures are not reflective of intraocular organisms. The most common pathogens causing postoperative endophthalmitis are staphylococci and streptococci. Less common organisms associated with exogenous endophthalmitis include gram-negative aerobic bacilli and fungi. We report a case of Serratia marcescens postoperative endophthalmitis in a normal host.

Aged↗
PubMed1991

Drug-induced aseptic meningitis. Diagnosis leads to quick resolution.

Drug-induced aseptic meningitis is a syndrome that should be considered in the differential diagnosis of acute and recurrent aseptic meningitis. It has been observed in all age-groups and can occur following the use of a wide spectrum of pharmaceutical agents. Presumptive diagnosis is made by demonstrating the resolution of symptoms after drug withdrawal, and definitive diagnosis is made by conducting a drug rechallenge. Fortunately, the syndrome is usually benign and resolves quickly following drug cessation.

Animals↗
PubMed1991

Atypical pneumonias. Clinical diagnosis and empirical treatment.

Atypical pathogens play an important role in the pathogenesis of community-acquired pneumonias. Early definitive diagnosis is often difficult. Careful attention must be given to the patient's history and other diagnostic clues. When a specific pathogen seems very likely to be the cause, appropriate and cost-effective empirical therapy is best accomplished with a single-drug regimen. However, when typical and atypical pathogens are suspected, combination drug therapy is preferred until the diagnosis is firm and one of the two antibiotics can be dropped.

Anti-Bacterial Agents↗
PubMed1991

Listeria.

Explore the source record for details and available documents.

Adult↗
PubMed1991

Reduction of capsular polysaccharide and potentiation of aminoglycoside inhibition in gram-negative bacteria by bismuth subsalicylate.

Bismuth subsalicylate (BSS), sodium salicylate, and bismuth nitrate were compared with respect to their effects on capsular polysaccharide (CPS) production, bacterial growth inhibition, and potentiation of aminoglycoside inhibition on strains of Gram-negative bacteria. At 250 microM, BSS reduced CPS production in Klebsiella pneumoniae cultures by greater than 90% in contrast to a 36% reduction by salicylate. At 500 microM, salicylate reduced CPS by 52%, versus a 70% reduction by bismuth nitrate. Substantial reduction of CPS production by BSS occurred before bacterial growth inhibition was observed. However, BSS at 250 microM decreased cell viability by 21%, and at 1 mM by 50%. Bismuth nitrate was equally inhibitory to cell growth. Salicylate at 1 mM did not affect bacterial cell counts. The susceptibility of selected Gram-negative bacteria to aminoglycoside antibiotics was studied in the presence of BSS or salicylate. Generally, salicylate at 2.5 mM reduced the concentration of aminoglycoside required to inhibit culture growth for 24 h (IC24) by two-fold. In contrast, 700 microM BSS reduced the IC24 for amikacin four-fold for a resistant K. pneumoniae strain. At 500 microM, BSS reduced the IC24 of gentamicin seven-fold for Salmonella typhimurium. Inhibitory concentrations of amikacin or tobramycin for Enterobacter cloacae or Serratia marcescens were also reduced seven-fold with 500 microM BSS. Bismuth nitrate reduced the IC24 of tobramycin by four-fold for E. cloacae. Thus, the profound effects of BSS on CPS production and aminoglycoside potentiation were due to the additive effects of bismuth and salicylate ions, whilst its effects on growth inhibition were due to the bismuth ion.

Aminoglycosides↗