Henry D. Isenberg

Ingestion of yogurt containing Lactobacillus acidophilus as prophylaxis for candidal vaginitis.

OBJECTIVE To assess whether daily ingestion of yogurt containing Lactobacillus acidophilus prevents vulvovaginal candidal infections. DESIGN Crossover trial for at least 1 year during which patients were examined for candidal infections and colonizations while receiving either a yogurt-free or a yogurt-containing diet. Patients served as their own controls. SETTING Ambulatory infectious disease center in a teaching hospital providing tertiary care. PATIENTS Thirty-three women with recurrent candidal vaginitis were eligible after recruitment from community practices and clinics and through advertising. Twelve patients were eliminated for protocol violations. Of the remaining 21 patients, 8 who were assigned to the yogurt arm initially refused to enter the control phase 6 months later. Thus, 13 patients completed the protocol. INTERVENTIONS Women ate yogurt for 6 months of the study period. MEASUREMENTS Colonization of lactobacilli and candida in the vagina and rectum; candidal infections of the vagina. MAIN RESULTS Thirty-three eligible patients were studied. A threefold decrease in infections was seen when patients consumed yogurt containing Lactobacillus acidophilus. The mean (+/- SD) number of infections per 6 months was 2.54 +/- 1.66 in the control arm and 0.38 +/- 0.51 per 6 months in the yogurt arm (P = 0.001). Candidal colonization decreased from a mean of 3.23 +/- 2.17 per 6 months in the control arm to 0.84 +/- 0.90 per 6 months in the yogurt arm (P = 0.001). CONCLUSION Daily ingestion of 8 ounces of yogurt containing Lactobacillus acidophilus decreased both candidal colonization and infection.

VANCOMYCIN-RESISTANT ENTEROCOCCUS FAECIUM IN HOSPITALIZED CHILDREN

OBJECTIVE Determine the epidemiology and risk factors for colonization with vancomycin-resistant Enterococcus faecium. DESIGN Survey; case-control study. SETTING Childrens hospital. PATIENTS Pediatric oncology patients. INTERVENTION Contact isolation, restriction of vancomycin prescribing. RESULTS There was a high prevalence of colonization with vancomycin-resistant enterococci among pediatric oncology patients. The length of hospitalization and the administration of vancomycin and other intravenous antibiotics was associated with colonization. Prevention of colonization was associated with restriction of vancomycin use and contact isolation. CONCLUSIONS Vancomycin use may predispose to colonization with vancomycin-resistant E faecium. Vancomycin-resistant E faecium may be nosocomially spread. Contact isolation and restriction of vancomycin use may prevent spread of vancomycin-resistant E faecium.

Central catheter infections: Single- versus triple-lumen catheters: Influence of guide wires on infection rates when used for replacement of catheters☆

A prospective study was conducted over six months to determine if triple-lumen catheters were associated with a higher rate of infection than single-lumen catheters. A total of 502 central intravascular catheters were prospectively collected from 362 consecutive patients in the adult intensive care units. Semiquantitative and broth cultures were performed on distal and proximal catheter segments, with peripheral blood culture specimens drawn in febrile patients. The overall infection rate for the 502 catheters was 11.8 percent or 2.2 infections per 100 days at risk. The infection rates were: single-lumen lines, 8 percent; triple-lumen lines, 32 percent; and triple-lumen pulmonary artery catheters, 12 percent. When corrected for time at risk, the triple-lumen lines and the triple-lumen pulmonary artery catheters had the same rate of infection, which was three times greater than that of the single-lumen catheters. After correction for confounding variables such as the presence of diabetes mellitus, the use of hyperalimentation, the degree of illness, dialysis, or ultrafiltration, and the use of a guide wire to place a replacement line over a pre-existing one, the risk of infection remained significantly higher for triple-lumen than for single-lumen catheters. The use of a guide wire to place a new line over an old one also was associated with a trend towards an increased risk of infection.

Nosocomial Urinary-Tract Infections in a Skilled Nursing Facility†

Fifty‐five documented infections reported from an admission unit of a large skilled nursing facility (SNF) during a five‐month period were analyzed. Of these, 45 (82 percent) were urinary‐tract infections (UTIs), chiefly asymptomatic bacteriuria. Sixty‐three percent of the UTIs were acquired in the SNF, and the remainder were acquired during the preceding stay in a general hospital. Statistically, Proteus species infections were more common among the SNF‐acquired UTIs, whereas Pseudomonas aeruginosa infections were the most common among the hospital‐acquired UTIs. The following recommendations are made: 1) for previously hospitalized elderly patients in whom urinary‐tract sepsis develops soon after admission to an SNF, treatment should start with an antibiotic active against Pseudomonas aeruginosa while the results of cultures are pending; 2) symptomatic lower urinary‐tract infections caused by SNF‐acquired Proteus species should be treated with nalidixic acid or trimethoprim**‐sulfamethoxazole; 3) the term “nosocomial infection” should be broadened to include infections acquired in long‐term care institutions; and 4) infection surveillance should be started in selected long‐term care institutions for the elderly as part of an expanded National Nosocomial Infections Survey.

Is hand washing really needed in an intensive care unit

OBJECTIVES To determine whether a rigorous antiseptic hand washing of bare hands with 4% chlorhexidine and alcohol reduced fingertip microbial colonization as compared with the use of boxed, clean, nonsterile latex gloves. In addition, to investigate if aseptic donning technique and/or a prior hand washing would reduce the level of glove contamination. DESIGN Prospective, randomized, crossover design, with each subject serving as his/her own control. SETTING University intensive care unit. SUBJECTS Forty-three intensive care nurses. INTERVENTIONS The fingertips of 20 nurses were cultured before and after a strict antiseptic hand washing and before and after the routine and aseptic donning of sterile gloves. Subsequently, the fingertips of 43 nurses were cultured before and after the casual donning of nonsterile gloves over unwashed hands and before and after a strict antiseptic hand washing. Fingertip cultures were plated directly on agar, incubated for 24 hrs, and counted and recorded as the number of colony-forming units (cfu) for each hand. Different colony types were then subcultured. MEASUREMENTS AND MAIN RESULTS Hand washing with antiseptic reduced colonization from 84 to 2 cfu (p < .001). The proportion of cases with > or = 200 cfu/hand was reduced from 30% to 9%. Aseptic or casual donning of sterile gloves, with or without prior antiseptic hand washing, resulted in consistently low glove counts between 0 and 1.25 cfu. Nonsterile gloves casually donned over washed or unwashed bare hands diminished the bioburden to 2.17 and 1.34 cfu, respectively. No qualitative difference was found in the microorganisms recovered from gloved or bare hands. CONCLUSIONS Antiseptic hand washing and the use of nonsterile gloves over unwashed hands confer similar reductions in the number of microorganisms. There is no additional benefit with the use of aseptic donning technique, prior antiseptic hand washing, or the use of individually packaged sterile gloves.

Evaluation of three disinfectants after in-use stress

Solutions of 2.0% and 3.4% glutaraldehyde, and of 0.5% phenate with 0.18% glutaraldehyde were stressed with a microbial and organic soil load for the periods advocated by the respective manufacturers. The disinfecting efficacy of the stressed solutions was challenged with Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Mycobacterium bovis (BCG), a water Mycobacterium sp. and Candida albicans. The three disinfectants were active against the fast-growing bacteria in appropriate dilutions; lesser dilutions of the glutaraldehyde solutions killed the mycobacteria and the yeast, while stressed phenate with glutaraldehyde did not. One hour exposure of the stressed disinfectants failed to kill the spore preparations while reducing the number of survivors.

Correlation of the Results of Antibiotic Synergy and Susceptibility Testing in Vitro with Results in Experimental Mouse Infections

Recent clinical isolates (approximately 150 strains) of the family Enterobacteriaceae were examined by agar diffusion, microdilution, and the Autobac automated system for their responses to beta-lactam antibiotics singly and in combination with amdinocillin (formerly called mecillinam). The ratio of ampicillin, carbenicillin, and cephalothin to amdinocillin was maintained at a 10:1 ratio in most of the evaluations. The same isolates were studied in mice challenged with 100 to 1000 LD50s and treated with graded doses of the antibiotics singly and in combination. Efficacy in vivo was based on the concentration of antibiotic in milligrams per kilograms (mg/kg) required to protect 50% of the animals (PD50). After a single administration of the antibiotics, plasma levels were determined in the critical time period (30 min to 4 hr) during which the acute, overwhelming systemic infections could be controlled by appropriate therapy. Regression curves comparing in vivo and in vitro results were used to establish cut-off points for categorizing bacterial susceptibility in each of the laboratory tests for the single agents and combinations. A high degree of synergism between amdinocillin and the beta-lactam agents was demonstrated in animals (54 to 78% of the strains examined) and to a lesser extent by laboratory methodologies. There was an excellent correlation of in vivo and in vitro responses to ampicillin, carbenicillin, and cephalothin alone and in combination with amdinocillin for those species for which the single antibiotics are generally indicated. The correlations validated the chosen cut-off points. The correlation of in vivo and in vitro responses to the single or combined antibiotics was generally poorer for those species not usually responsive to the single antibiotics. The greatest difficulty in predicting proper in vivo responses, based on the results of in vitro tests, was observed with amdinocillin.

Wound infection: Acute versus chronic cholecystitis

Wound infection in 239 patients who underwent cholecystectomy were analyzed retrospectively. Seventeen per cent of the patients with acute cholecystitis had wound infection compared with 8.9 per cent of patients with chronic cholecystitis. Bacteriology of wound infections revealed Staphylococcus aureus in 76.4 per cent of the chronic cholecystitis group and in 12.5 per cent of the acute cholecystitis group. Wound infection in the acute cholecystitis group involved gram-negative rods predominantly. Organisms were isolated from bile culture in 71.4 per cent of acute cholecystitis patients compared with 59.6 per cent of chronic cholecystitis patients. Of patients with positive bile cultures 11.3 per cent had wound infections compared with 6.8 per cent of patients with negative bile cultures. The most common organisms isolated from bile cultures with resultant wound infections were S epidermis, S aureus, and Klebsiella sp. Wound infection after cholecystectomy for chronic cholecystitis arises from external sources and not contaminated bile. Antibiotic therapy should be directed accordingly.

Microbiologic efficacy of a surgically constructed nipple valve.

The efficacy of a surgically constructed nipple valve in preventing reflux of colonic bacteria into the small bowel was evaluated. The nipple valve significantly decreased the number of S. marcescens, a marker bacterium, in the small bowel when compared with plain ileocolic anastomosis. In this study, the nipple valve prevented the reflux of bacteria similar to an intact ileocecal valve which suggests that the nipple valve is an effective bacteriologic barrier and may be used as a substitute for the ileocecal valve in patients with short bowel syndrome.