1/33. The emergence of decreased susceptibility to vancomycin in staphylococcus epidermidis.BACKGROUND: coagulase-negative staphylococci (CNS) are the major cause of nosocomial bloodstream infection. Emergence of vancomycin resistance among CNS is a serious public health concern, because CNS usually are multidrug-resistant, and glycopeptide antibiotics, among which only vancomycin is available in the United States, are the only remaining effective therapy. In this report, we describe the first bloodstream infection in the united states associated with a staphylococcus epidermidis strain with decreased susceptibility to vancomycin. methods: We reviewed the hospital's microbiology records for all CNS strains, reviewed the patient's medical and laboratory records, and obtained all available CNS isolates with decreased susceptibility to vancomycin. blood cultures were processed and CNS isolates identified by using standard methods; antimicrobial susceptibility was determined by using minimum inhibitory concentration (MIC) and disk-diffusion methods. Nares cultures were obtained from exposed healthcare workers (HCWs) to identify possible colonization by CNS with decreased susceptibility to vancomycin. RESULTS: The bloodstream infection by an S. epidermidis strain with decreased susceptibility to vancomycin occurred in a 49-year-old woman with carcinoma. She had two blood cultures positive for CNS; both isolates were S. epidermidis. Although susceptible to vancomycin by the disk-diffusion method (16-17 mm), the isolates were intermediate by MIC (8-6 microg/mL). The patient had received an extended course of vancomycin therapy; she died of her underlying disease. No HCW was colonized by CNS with decreased susceptibility to vancomycin. CONCLUSIONS: This is the first report in the united states of bloodstream infection due to S. epidermidis with decreased susceptibility to vancomycin. Contact precautions likely played a role in preventing nosocomial transmission of this strain, and disk-diffusion methods may be inadequate to detect CNS with decreased susceptibility to vancomycin.- - - - - - - - - - ranking = 1keywords = susceptibility (Clic here for more details about this article) |
2/33. Hospital-acquired brevundimonas vesicularis septicaemia following open-heart surgery: case report and literature review.Brevundimonas vesicularis (B. vesicularis) is a pseudomonad rarely encountered in human infection. A case of nosocomial septicaemia with this organism following open-heart surgery is presented, with a review of the literature. The isolate demonstrated resistance to ciprofloxacin and aztreonam, which has not yet been reported. Treatment with piperacillin/tazobactam resulted in full recovery. A review of the literature reveals that B. vesicularis is a virulent organism involved in serious infections such as central nervous system infection or bacteraemia, some of which are nosocomial. Meanwhile, empiric therapy for B. vesicularis infection should include a broad-spectrum antimicrobial agent until susceptibility results are known.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
3/33. Nosocomial cluster of candida lipolytica fungemia in pediatric patients.candida lipolytica has rarely been reported as a human pathogen. An apparent outbreak of candida lipolytica fungemia (n = 5 cases) occurred in a pediatric ward over a 9-week period. The five patients infected were hospitalized in three adjacent rooms and cared for by the same healthcare workers. The index patient had central venous catheter-related fungemia, whereas the second patient, who was in the adjacent single room, had transient fungemia. Three additional cases of fungemia occurred in patients with hematological disorders who shared the same room; all three patients had central venous catheters and had been receiving oral fluconazole prophylaxis (50 mg/day for more than 3 weeks) at the time of infection. in vitro susceptibility testing of the strains showed that the MIC of fluconazole for all the isolates was 32 microg/ml. Random amplified polymorphic dna analysis provided evidence of the clonal origin of the isolates, but the source of the outbreak was not identified. All four patients with persistent fungemia were successfully treated via catheter removal or empiric amphotericin b treatment. This outbreak shows the potential for the nosocomial epidemic transmission of candida lipolytica.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
4/33. Outbreak of nosocomial infections due to extended-spectrum beta-lactamase-producing strains of enteric group 137, a new member of the family enterobacteriaceae closely related to citrobacter farmeri and citrobacter amalonaticus.A member of the enterobacteriaceae initially identified as kluyvera cryocrescens by the MicroScan Gram-Negative Combo 13 panel caused an outbreak of nosocomial infections in four patients (pneumonia, n = 2; urinary tract infection, n = 1; wound infection, n = 1) and urinary tract colonization in one patient. When the strains were tested by the Enteric Reference Laboratory of the Centers for disease Control and Prevention, biochemical results were most compatible with yersinia intermedia, kluyvera cryocrescens, and citrobacter farmeri but identification scores were low and test results were discrepant. However, when the biochemical test profile was placed in the computer database as a new organism, all strains were identified as the organism with high identification scores (0. 999968 to 0.999997) and no discrepant test results. By 16S rRNA sequence analysis the organism clustered most closely with, but was distinct from, citrobacter farmeri and citrobacter amalonaticus. Based on its unique biochemical profile and rRNA sequence, this organism is designated Enteric Group 137. Restriction endonuclease analysis and taxonomic antibiograms of strains causing the outbreak demonstrated a single clone of Enteric Group 137, and antibiotic susceptibility testing revealed the presence of extended-spectrum beta-lactamase (ESBL) resistance. Enteric Group 137 appears to be a new opportunistic pathogen that can serve as a source of ESBL resistance in the hospital.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
5/33. Nosocomial transmission of tuberculosis to a nurse demonstrated by means of spoligotyping of a formalin-fixed bronchial biopsy.BACKGROUND: Tuberculosis was diagnosed in a student nurse. The source of infection was unknown and no positive culture was available. methods: The diagnosis of tuberculous bronchitis was established on the grounds of a positive Mantoux test, the pathology of a bronchial biopsy and the results of a CT scan of the thorax. Spoligotyping of, for example, formalin-fixed tissue makes it possible to establish the diagnosis in a later phase after all. RESULTS: Cultures for mycobacterium tuberculosis were not performed for the student nurse and Ziehl-Neelsen staining of the formalin-fixed bronchial biopsy was negative. The final tuberculosis diagnosis was confirmed by a PCR fingerprint technique, i.e., spoligotyping of a formalin-fixed biopsy specimen. By means of contact investigation and identification of the strain via spoligotyping, comparison of the spoligo patterns made it possible to treat both the patient and those infected by this person correctly. CONCLUSIONS: When there is a pronounced suspicion of tuberculosis and a microbiological culture is not available, it is recommended that supplementary spoligotyping of clinical specimens be carried out. The purpose is to confirm the diagnosis, trace the presumed source case and indirectly to provide information on the drug susceptibility of the relevant M. tuberculosis strain.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
6/33. treatment failure due to methicillin-resistant staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin.We report the first instance in australia of treatment failure due to a strain of methicillin-resistant staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin--heteroresistant vancomycin-intermediate S. aureus (hVISA). The infection occurred in a 41-year-old man with multiple risk factors. No transmission of the organism to other patients or the environment was detected. This case may herald the beginning of a new phase of staphylococcal resistance in australia.- - - - - - - - - - ranking = 0.41666666666667keywords = susceptibility (Clic here for more details about this article) |
7/33. Staphylococcus aureus resistant to vancomycin--united states, 2002.Staphylococcus aureus is a cause of hospital- and community-acquired infections. In 1996, the first clinical isolate of S. aureus with reduced susceptibility to vancomycin was reported from japan. The vancomycin minimum inhibitory concentration (MIC) result reported for this isolate was in the intermediate range (vancomycin MIC=8 microg/mL) using interpretive criteria defined by the National Committee for Clinical Laboratory Standards. As of June 2002, eight patients with clinical infections caused by vancomycin-intermediate S. aureus (VISA) have been confirmed in the united states. This report describes the first documented case of infection caused by vancomycin-resistant S. aureus (VRSA) (vancomycin MIC > or = 32 microg/mL) in a patient in the united states. The emergence of VRSA underscores the need for programs to prevent the spread of antimicrobial-resistant microorganisms and control the use of antimicrobial drugs in health-care settings.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
8/33. Emergence of vancomycin-intermediate Staphylococcus aureus in a Belgian hospital: microbiological and clinical features.In 1999, all clinical Staphylococcus aureus isolates from patients admitted to a Belgian University hospital were tested for decreased vancomycin susceptibility. Three vancomycin-intermediate Staphylococcus aureus (VISA) and four hetero-VISA strains were detected among 2145 isolates tested. They emerged from strains that belonged to locally endemic methicillin-resistant S. aureus (MRSA) genotypes in three patients who had received repeated courses of vancomycin therapy. A cystic fibrosis patient with MRSA/VISA-associated broncho-pulmonary exacerbation was successfully treated by continuous vancomycin infusion plus fusidic acid followed by oral minocycline-fusidic acid. Two other patients had VISA recovered from specimens of undetermined clinical significance. Emergence of VISA variants of endemic MRSA strains in belgium warrants active microbiological surveillance and careful monitoring of vancomycin therapy. Therapy with high-dose vancomycin administered by continuous infusion in combination with other antimicrobials may be a therapeutic option worth investigating for VISA infection.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
9/33. Potential nosocomial exposure to mycobacterium tuberculosis from a bronchoscope.OBJECTIVE: To investigate a possible nosocomial outbreak of tuberculosis (TB). DESIGN: Retrospective cohort study. SETTING: Community hospital. methods: We reviewed medical records, hospital infection control measures, and potential locations of nosocomial exposure. We examined the results of acid-fast bacilli (AFB) smears, cultures, and drug susceptibility testing, and performed a dna fingerprint analysis. We observed laboratory specimen processing procedures and bronchoscope disinfection procedures. We also reviewed bronchoscopy records. RESULTS: In October 2000, three patients had bronchoscopy specimen cultures that were positive for mycobacterium tuberculosis. Of the three, only one had clinical signs and symptoms consistent with TB and positive AFB sputum smears. The other two did not have signs and symptoms consistent with TB and had no known exposure to individuals with infectious TB. The three M. tuberculosis isolates had matching dna fingerprints. No evidence of laboratory cross-contamination was identified. The three culture-positive specimens of M. tuberculosis were collected with the same bronchoscope within 9 days. This bronchoscope was inadequately cleaned and disinfected between patients, and the automated reprocessor used was not approved for use with the hospital bronchoscope. CONCLUSIONS: One of the bronchoscopes at this hospital was contaminated with M. tuberculosis during bronchoscopy of an AFB-smear-positive patient. Subsequent specimen contamination likely occurred because the bronchoscope had been inadequately cleaned and disinfected. patients who subsequently underwent bronchoscopy were also potentially exposed to M. tuberculosis from this bronchoscope.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
10/33. bacteremia caused by Stomatococcus mucilaginosus: report of seven cases and review of the literature.During a three-year period eight patients with blood cultures positive for Stomatococcus mucilaginosus were identified at two university hospitals. One patient without any signs of infection had a central venous catheter that was colonized with this organism, two patients had transient bacteremia without definite relationship to underlying disease, whereas the remaining five patients suffered from clinically significant infections. Of these last five patients, one had undergone prior head and neck surgery and four had hematologic malignancy with mild to severe neutropenia; two of the latter patients developed the infection subsequent to dental surgery. Besides neutropenia and mucosal damage in the oropharynx, quinolone antibacterial prophylaxis may have been an additional risk factor for the development of S. mucilaginosus bacteremia in these patients. A thorough review of the literature revealed that in addition to our findings, endocarditis and foreign body infections are further typical clinical manifestations. Although the overall antibiotic susceptibility pattern of S. mucilaginosus resembles that of streptococci, it is suggested that penicillin g may not be the drug of choice for initial therapy of particularly severe infections. S. mucilaginosus can be easily differentiated from other gram-positive bacteria when certain key criteria (e.g. adherence to agar surfaces, poor growth on Mueller-Hinton agar, presence of a capsule) as well as an array of biochemical tests, including commercially available identification systems, are applied. Our own and published data emphasize that both microbiologists and clinicians should be increasingly aware of this opportunistic pathogen.- - - - - - - - - - ranking = 0.083333333333333keywords = susceptibility (Clic here for more details about this article) |
| | Next -> |