Multiple antibiotic-resistant Klebsiella and Escherichia coli in nursing homes.

CONTEXT: Infections caused by ceftazidime sodium-resistant gram-negative bacteria that harbor extended-spectrum beta-lactamases (ESBLs) are increasing in frequency in hospitals in the United States. OBJECTIVES: To report a citywide nursing home-centered outbreak of infections caused by ESBL-producing gram-negative bacilli and to describe the clinical and molecular epidemiology of the outbreak. DESIGN: Hospital-based case-control study and a nursing home point-prevalence survey. Molecular epidemiological techniques were applied to resistant strains. SETTINGS: A 400-bed tertiary care hospital and a community nursing home. PATIENTS: Patients who were infected and/or colonized with ceftazidime-resistant Escherichia coli, Klebsiella pneumoniae, or both and controls who were admitted from nursing homes between November 1990 and July 1992. MAIN OUTCOME MEASURES: Clinical and epidemiological factors associated with colonization or infection by ceftazidime-resistant E coli or K pneumoniae; molecular genetic characteristics of plasmid-mediated ceftazidime resistance. RESULTS: Between November 1990 and October 1992, 55 hospital patients infected or colonized with ceftazidime-resistant E coli, K pneumoniae, or both were identified. Of the 35 admitted from 8 nursing homes, 31 harbored the resistant strain on admission. All strains were resistant to ceftazidime, gentamicin, and tobramycin; 96% were resistant to trimethoprim-sulfamethoxazole and 41% to ciprofloxacin hydrochloride. In a case-control study, 24 nursing home patients colonized with resistant strains on hospital admission were compared with 16 nursing home patients who were not colonized on hospital admission; independent risk factors for colonization included poor functional level, presence of a gastrostomy tube or decubitus ulcers, and prior receipt of ciprofloxacin and/or trimethoprim-sulfamethoxazole. In a nursing home point-prevalence survey, 18 of 39 patients were colonized with ceftazidime-resistant E coli; prior receipt of ciprofloxacin or trimethoprim-sulfamethoxazole and presence of a gastrostomy tube were independent predictors of resistance. Plasmid studies on isolates from 20 hospital and nursing home patients revealed that 17 had a common 54-kilobase plasmid, which conferred ceftazidime resistance via the ESBL TEM-10, and mediated resistance to trimethoprim-sulfamethoxazole, gentamicin, and tobramycin; all 20 isolates harbored this ESBL. Molecular fingerprinting showed 7 different strain types of resistant K pneumoniae and E coli distributed among the nursing homes. CONCLUSIONS: Nursing home patients may be an important reservoir of ESBL-containing multiple antibiotic-resistant E coli and K pneumoniae. Widespread dissemination of a predominant antibiotic resistance plasmid has occurred. Use of broad-spectrum oral antibiotics and probably poor infection control practices may facilitate spread of this plasmid-mediated resistance. Nursing homes should monitor and control antibiotic use and regularly survey antibiotic resistance patterns among pathogens

Evaluation of trends in ue of antibiotics and resistance in selected bacterial pathogens

BACKGROUND: Evaluation of antibiotic consumption and the surveillance of bacterial pathogens resistance appears to be an indispensable part of antibiotic policy. The aim of this study was to evaluate dynamics of antibiotics consumption and resistance development in selected bacterial strains (Pseudomonas aueruginosa, Staphylococcus aureus and Staphylococcus epidermidis) in the environment of Faculty Hospital. METHODS AND RESULTS: The analysis was focused on the development of antibiotic consumption and monitoring of the development of bacterial resistance. Samples were taken in internal and surgical departments of General Faculty Hospital in Prague in 1992, 1995, and 1999. The evaluation of antibiotic consumption was based on Anatomical Therapeutic and Chemical classification system and the Defined Daily Doses (DDD). The consumption in the follow up period almost doubled in surgical department while in internal medicine department was decreased by almost one third. In both department, namely in the surgical one significant increase of bacterial resistance of tested antibiotics was noted. CONCLUSION: The important part of the local antibiotic policy is the monitoring of development of bacterial resistance and consumption of antibiotics.

Department of pharmacy-initiated program for streamlining empirical antibiotic therapy.

The outcome of a department of pharmacy-initiated "streamlining" study designed to promote cost-conscious modifications of empirically selected antibiotic therapy is described. Two hundred forty-one evaluable adult patients started on restricted-use antibiotics at this university-affiliated community private teaching hospital were enrolled in a 9-week prospective streamlining study. Patients were alternately assigned to a Control (i.e., no pharmacist-initiated streamlining recommendations offered based on culture and susceptibility reports) or a Pharmacist Intervention group (i.e., pharmacist offers recommendations to streamline therapy). A statistically significant greater number of patients had their empiric antibiotic treatment courses modified to more appropriate antibiotic choices after receipt of culture and susceptibility reports among private prescribers in the Pharmacist Intervention group (83%) than in the Control group (38%) (p = .006). Additionally, pharmacists were overall successful in gaining prescriber acceptance for 64% of recommended changes of empiric antibiotic treatment courses before the receipt of culture and susceptibility reports (e.g., dose and/or frequency changes). There was no program effect observed with respect to improved physician response to microbiologic data that would allow streamlining empirical antibiotic choices in the Housestaff (i.e., medical or surgical residents), or infectious disease consultant prescriber groups. Projected overall annual cost savings that would be achieved as a result of continued efforts by pharmacists directed at streamlining empirical "restricted" antibiotic regimens is approximately +40,000

J Infect Dis. 2002 Nov 15;186(10):1430-7. Epub 2002 Oct 23.
Detection of attenuated, noninfectious spirochetes in Borrelia burgdorferi-infected mice after antibiotic treatment.

Xenodiagnosis by ticks was used to determine whether spirochetes persist in mice after 1 month of antibiotic therapy for vectorborne Borrelia burgdorferi infection. Immunofluorescence and polymerase chain reaction (PCR) were used to show that spirochetes could be found in Ixodes scapularis ticks feeding on 4 of 10 antibiotic-treated mice up to 3 months after therapy. These spirochetes could not be transmitted to naive mice, and some lacked genes on plasmids correlating with infectivity. By 6 months, antibiotic-treated mice no longer tested positive by xenodiagnosis, and cortisone immunosuppression did not alter this result. Nine months after treatment, low levels of spirochete DNA could be detected by real-time PCR in a subset of antibiotic-treated mice. In contrast to sham-treated mice, antibiotic-treated mice did not have culture or histopathologic evidence of persistent infection. These results provide evidence that noninfectious spirochetes can persist for a limited duration after antibiotics but are not associated with disease in mice

Sequential intravenous/oral antibiotic vs. continuous intravenous antibiotic in the treatment of pyogenic liver abscess.

AIM: Pyogenic liver abscesses result in substantial morbidity and mortality. Antimicrobial regimens using sequential intravenous/oral therapy may reduce the length of hospital stay. In this retrospective analysis, the efficacy of continuous intravenous antibiotic therapy (group I) vs. sequential intravenous/oral antibiotic therapy (group II) was studied in patients with pyogenic liver abscess. METHODS: One hundred and twelve consecutive patients (55 in group I and 57 in group II) with pyogenic liver abscess were analysed. Clinical response, length of hospital stay and relapse rates were examined. RESULTS: Group II had a significantly shorter duration of intravenous antibiotic treatment (3.2 weeks vs. 5.9 weeks, P < 0.01) and a shorter length of hospital stay (28 days vs. 42 days, P < 0.01) when compared to group I. Oral antibiotics were prescribed for a median duration of 2.9 weeks in group II after discharge. No relapse occurred within 6 weeks after the completion of treatment in both groups. The cost of therapy was significantly lower in group II than in group I by 33%. CONCLUSIONS: A sequential intravenous/oral antibiotic regime is a safe and effective treatment for pyogenic liver abscess. This reduces the cost of therapy and the length of hospital stay

Community-acquired bacteraemia and antibiotic resistance. Trends during a 17-year period in a Danish county.

INTRODUCTION: The aim was to ascertain the prevalence of antibiotic resistance among blood isolates from patients with community-acquired bacteraemia and to relate it to antibiotic consumption. METHODOLOGY: Cases of community-acquired bacteraemia were identified in a regional bacteraemia register in the County of Northern Jutland. The study included 3974 episodes in 3805 patients during a 17-year period. Total regional consumption of antibiotics was expressed in Defined Daily Doses (DDD). RESULTS: The prevalence of antibiotic resistance was stable with few exceptions. The most notable time trend was noted for Escherichia coli for which the prevalence of resistance to ampicillin increased from 17% (95% confidence limits (CL) 12-23%) to 28% (95% CL 23-33%); for other Enterobacteriaceae the increase was from 73% (95% CL 61-83%) to 86% (95% CL 77-92%). The prevalence of resistance to aminoglycosides, fluoroquinolones and third-generation cephalosporins remained low among all isolates of Enterobacteriaceae. Regional antibiotic consumption ranged from 10.2 to 13.6 DDD/1000 inhabitants/day. Consumption of penicillins with Gram-negative spectrum reached a maximum of 4.6 DDD/1000 inhabitants/day in 1993 and decreased towards the end of the study period. The prevalence of ampicillin-resistant E. coli was positively correlated with consumption of penicillins with Gram-negative spectrum; the correlation was stronger when adjustment was made for co-selection by tetracyclines and sulphonamides. CONCLUSION: Therapeutic options for community-acquired bacteraemia have not yet become seriously limited by prevalence of acquired antibiotic resistance. Still we found some evidence that consumption of penicillins with Gram-negative spectrum, sulphonamides and tetracyclines promotes antibiotic resistance among Enterobacteriaceae

Antibiotics are often used to treat viral upper respiratory tract infections, even though they are usually ineffective. However, frequent inappropriate antibiotic use contributes to the emergence of drug-resistant bacterial pathogens. This study used a national database to evaluate antibiotic use in treating upper respiratory tract infections in emergency departments. METHODS: Data were obtained from the 1996 National Hospital Ambulatory Medical Care Survey. Antibiotic prescribing rates were examined for colds, upper respiratory tract infections, and acute bronchitis. Patients with comorbid conditions or secondary diagnoses, such as chronic obstructive pulmonary disease, pneumonia, sinusitis, and HIV, were excluded. Bivariate and multivariate analyses were used to assess predictors of antibiotic use. RESULTS: Overall, there were an estimated 2.7 million ED visits for colds, upper respiratory tract infections, and bronchitis by children and adults in 1996. Antibiotics were prescribed for 24.2% (95% CI 18.9, 29.5) of patients with common colds and upper respiratory tract infections and for 42.2% (95% CI 35.2, 49.2) of patients with bronchitis. There were no significant associations between antibiotic use and patient race, sex, Hispanic ethnicity, geographic location, or source of payment. Antibiotics were prescribed less often by interns or residents than by staff or other physicians (odds ratio 0.43; 95% CI 0.19, 0.98), and patients younger than 18 years were less likely to receive antibiotics than adults (odds ratio 0.32; 95% CI 0.20, 0.52). Smokers were 4.3 (95% CI 2.2, 8.3) times more likely to receive antibiotics than nonsmokers. CONCLUSION: Antibiotics are commonly prescribed for ED patients with upper respiratory tract infections even though they are usually ineffective in otherwise healthy adults. Efforts should be made to reduce inappropriate antibiotic use for the sake of containing costs, preventing side effects, and limiting the spread of antibiotic resistance

Occurrence and antibiotic resistance of mesophilic Aeromonas in three riverine freshwaters of marrakech, morocco.

In order to evaluate the impact of pollution and sewage on the occurrence and antibiotic resistance of mesophilic aeromonads in riverine freshwaters of Marrakech, samples were collected from three rivers (Oukaimeden, Ourika, and Tensift) upstream and downstream from the principal bordering villages. During a 2-year study, indicators of pollution increased dramatically in the downstream waters. Bacterial indicators (faecal coliforms and faecal streptococci) correlated with mesophilic aeromonads only in heavily polluted waters. In low and moder-ately polluted sources, densities of mesophilic aeromonads were independent of water quality indicators and did not correlate statistically with faecal indicators. Average counts of Aeromonas in low and heavily polluted waters were 2.5 -103 and 2.1 - 106 colony forming units per 100 ml, respectively. The biochemical identification of 841 isolates indicated a predominance of A. caviae in heavily and moderately polluted water and sediment. A. hydrophila was dominant only in low polluted waters and when the temperature was below 12C. High densities of A. sobria were found in low, moderately polluted, or cleaned waters and when the water temperature was above 18C. All selected isolates (total = 841) were tested for antibiotic susceptibility against 21 antibiotics. Antibiotic resistance frequen-cies recorded were: ampicillin and amoxicillin, 100%; novobiocin, 96%; cefalotin, 81%; colistin, 72%; sulfamethoxazole, 40%; cefamandole, 37%; polymyxin B, 23%; trimethoprim, 17%; erythromycin, 15%; streptomycin, 8%; amoxicillin-clavulanate, 5%. Resistance to cefotaxime, kanamycin, gentamycin, chloramphenicol, tetracycline, oxytetracycline, nalidixic acid, rifampicin, or trimethoprim-sulfameth-oxazole was found to be <5%. Antibiotic resistance rates did vary according to the source of a strain"s isolation, and high numbers of antibiotic resistant strains were recorded in polluted samples. Since no correlation between mesophilic aeromonads and conventional faecal pollution indicators was observed in low or moderately polluted waters, and since these freshwaters are used for domestic supply, we propose the use of mesophilic aeromonads as complementary water pollution indicators to ensure the safety of water

The development of a group B streptococcus prevention policy at a community hospital.

BACKGROUND AND OBJECTIVES: In 1996, the Centers for Disease Control (CDC) issued guidelines for antepartum antibiotic prophylaxis of group B streptococcal (GBS)-positive women. The objective of this study is to document results of a GBS prophylaxis policy at one nonacademically affiliated, community hospital and discern its effectiveness with regard to compliance as well as in decreasing the incidence of early onset GBS (EOGBS) disease. METHODS: The development of a GBS-prevention policy at the Women's Hospital of Greensboro (WHG) was documented by means of interviews and examination of minutes of meetings. Effectiveness of the policy was assessed by calculating the percentage of all GBS+ or unknown mothers who received antepartum antibiotics during a 1-year period. Additionally, all newborns with any positive GBS culture during the past 13 years at WHG were identified. RESULTS: The policy was formulated and distributed during a 6-month period by strong leadership, community "buy-in," and an educational seminar. A preprinted physician order was written so that all GBS-positive/unknown mothers would receive antepartum antibiotics. Additionally, a clinical pathway was used to track and monitor maternal GBS status. During October 1, 1999 to September 30, 2000, 1124 (23.1%) mothers were found to be GBS positive/unknown. Of those who delivered an infant >37 weeks' gestation and who could be linked to the pharmacy database, 777 (91.1%) received antepartum antibiotics. The incidence of EOGBS disease at WHG before 1996 was 1.93 +/- 0.7/1000 births compared to 0.4 +/- 0.05/1000 after the issuance of the guidelines (p = 0.002, t-test). CONCLUSIONS: Over 90% of GBS-positive mothers were treated with antibiotics at WHG. Associated with this high adherence rate to the CDC guidelines has been a five-fold decrease in the incidence of EOGBS disease. We attribute these results to the implementation of a preprinted physician order sheet to direct intrapartum antibiotics for women with GBS positive or unknown colonization and the use of a clinical pathway to track GBS colonization status

Behavior of pythium Torulosum zoospores during their interaction with tobacco roots and Bacillus cereus.

Bacillus cereus UW85 suppresses seedling damping-off diseases caused by Oomycetes and produces antibiotics that inhibit development of Oomycetes in culture. The goal of this study was to determine how UW85 and its antibiotics affected the behavior of an Oomycete, Pythium torulosum, in its interaction with plant roots. We studied tobacco seedlings inoculated with zoospores of P. torulosum and UW85 culture, culture filtrate, washed cells, antibiotics (zwittermicin A or kanosamine), purified from cultures of UW85, and UW030, a mutant of UW85 that does not suppress disease and does not produce the antibiotics. Microscopic observation revealed that all of the treatments inhibited zoospore activity around roots and encystment on roots. Treatment with UW85 culture, culture filtrate, zwittermicin A, or kanosamine delayed cyst germination and the elongation rate of germ tubes, whereas treatment with UW030 or washed UW85 cells did not. In an in vitro seedling bioassay of disease suppression, the antibiotics, zwittermicin A and kanosamine, suppressed disease singly or together, although UW85 culture suppressed disease more effectively than did the antibiotics. The results show that B. cereus cultures affect zoospore behavior in the presence of roots, and B. cereus-produced antibiotics, zwittermicin A and kanosamine, contribute to disease suppression and inhibition of germ tube elongation in the presence of the plant root