Resistant Enterococcus Species Research Articles

Emergence of Carbapenem resistant Gram negative and vancomycin resistant Gram positive organisms in bacteremic isolates of febrile neutropenic patients: A descriptive study

BackgroundThis study was conducted to evaluate drug resistance amongst bacteremic isolates of febrile neutropenic patients with particular emphasis on emergence of carbapenem resistant Gram negative bacteria and vancomycin resistant Enterococcus species.MethodsA descriptive study was performed by reviewing the blood culture reports from febrile neutropenic patients during the two study periods i.e., 1999–00 and 2001–06. Blood cultures were performed using BACTEC 9240 automated system. Isolates were identified and antibiotic sensitivities were done using standard microbiological procedures.ResultsSeven twenty six febrile neutropenic patients were admitted during the study period. A total of 5840 blood cultures were received, off these 1048 (18%) were culture positive. Amongst these, 557 (53%) grew Gram positive bacteria, 442 (42%) grew Gram negative bacteria, 43 (4%) fungi and 6 (1%) anaerobes. Sixty (5.7%) out of 1048 positive blood cultures were polymicrobial. In the Gram negative bacteria, Enterobacteriaceae was the predominant group; E. coli was the most frequently isolated organism in both study periods. Amongst non- Enterobacteriaceae group, Pseudomonas aeruginosa was the commonest organism isolated during first study period followed by Acinetobacter spp. However, during the second period Acinetobacter species was the most frequent pathogen.Enterobacteriaceae group showed higher statistically significant resistance in the second study period against ceftriaxone, quinolone and piperacillin/tazobactam, whilst no resistance observed against imipenem/meropenem. The susceptibility pattern of Acinetobacter species shifted from sensitive to highly resistant one with significant p values against ceftriaxone, quinolone, piperacillin/tazobactam and imipenem/meropenem. Amongst Gram positive bacteria, MRSA isolation rate remained static, vancomycin resistant Enterococcus species emerged in second study period while no Staphylococcus species resistant to vancomycin was noted.ConclusionThis rising trend of highly resistant organisms stresses the increasing importance of continuous surveillance system and stewardship of antibiotics as strategies in the overall management of patients with febrile neutropenia.

Bacterial Contamination of Keyboards: Efficacy and Functional Impact of Disinfectants

The increasing use of computers in patient areas has made keyboards important reservoirs for pathogens, possibly contributing to health care-related hospital infections. Current CDC (Centers for Disease Control and Prevention) guidelines for hand hygiene could nullify the risk of transmitting pathogens from computer keyboards to patients, but numerous studies show that fewer than half of health care workers comply with them. This study examined the efficacy of six disinfectants, three containing quaternary ammonium and one each containing chlorine, alcohol, and phenol, against three microorganisms that were innoculated into computer keyboards. The test organisms were oxacillin-resistant Staphylococcus aureus (ORSA), Pseudomonas aeruginosa, and vancomycin- resistant Enterococcus (VRE) species. Specimens were collected using swabs moistened with trypticase soy broth from 25 computer keyboards in two intensive care units dealing with burns and cardiothoracic disorders, respectively, as well as six nursing units whose patients were receiving short-term care. All 25 keyboards harbored two or more microorganisms before disinfection. Coagulase-negative staphylococci, diphtheroids, Micrococcus species, and Bacillus species all were found in at least half the keyboards tested. Pathogens recovered from keyboard cultures included ORSA, Vancomycin-susceptible Enterococccus species, Aspergillus flavus, and A. niger. All six disinfectants were very effective in removing or inactivating ORSA, VRE, and P. aeruginosa. A water control also proved to be an excellent means of removing pathogens. In all instances, more than 95% of test bacteria were removed or inactivated. The quaternary ammonium preparations were very active against VRE for the entire 48-hour test period. Alcohol, in contrast, exerted no sustained, clinically relevant activity. The quaternary ammonium compounds also were active for a sustained time against P. aeruginosa, although not as active as against VRE. As was the case for VRE, alcohol was not highly active for a sustained period against P. aeruginosa. Applying disinfectant did not appear to impair keyboard function. The investigators recommend that computer keyboards used in patient care areas be disinfected each day and whenever visibly soiled or contaminated with blood. Caregivers should avoid touching keyboards with contaminated hands. If keyboard covers are used, they also should be disinfected. Mobile computers used by patients should be disinfected after every session. A keyboard used by an isolated patient should remain in the same room until no longer needed, and then disinfected.

Evaluation of microbicidal activity of a new disinfectant: Sterilox® 2500 against Clostridium difficile spores, Helicobacter pylori, vancomycin resistant Enterococcus species, Candida albicans and several Mycobacterium species

The microbicidal activity of a new disinfectant Sterilox®, a super-oxidized water, containing a mixture of oxidizing substances, was tested against Clostridium difficile spores, Helicobacter pylori, vancomycin resistant Enterococcus species, Candida albicans and several Mycobacterium species using membrane filters. All tests were performed in duplicate with and without added horse serum at 1% and 5% v/v. Distilled water, 0·35% peracetic acid (Nu-Cidex®) and 2% glutaraldehyde were included as controls. Sterilox: spore suspension (9:1 v/v) achieved log 10 kill of >5 with 5% horse serum in 2 min against H. pylori, vancomycin resistant Enterococcus species, C. albicans and four atypical Mycobacterium species: M. avium, M. chelonei, M. xenopi and M. smegmatis. Sporicidal activity of Sterilox against Clostridium difficile was markedly diminished in the presence of 5% horse serum. Sterilox may be am effective alternative in endoscopy units, as it is a potent microbicidal agent and the manufacturer claims it is not corrosive to metal and is non-toxic to biological tissues.

Comparison of the in vitro activity of levofloxacin and other antimicrobial agents against vancomycin-susceptible and vancomycin resistant Enterococcus species

The in vitro activities of levofloxacin and other antibiotics against 133 clinical isolates of vancomycin-resistant and vancomycin-susceptible enterococci were evaluated. Only 14 (39%) of the vancomycin-susceptible isolates and 11 (11%) of the vancomycin-resistant isolates were susceptible to levofloxacin. Levofloxacin exhibited a marked inoculum effect for all enterococci tested. These results suggest that levofloxacin may be of limited use in the treatment of serious enterococcal infections.