USA300 methicillin-resistant S. aureus (USA300 MRSA) colonization and the risk of MRSA infection in residents of extended-care facilities.

To examine the pathogenesis of USA300 MRSA infection in long-term care residents, we performed a retrospective cohort study of 1691 adult residents of two extended-care facilities from 2003 to 2007 to assess whether the risk of subsequent MRSA infection is higher in USA300 MRSA-colonized residents compared to non-colonized residents or non-USA300 MRSA colonized residents. Six per cent of residents were colonized with USA300 MRSA; 12% of residents were colonized with non-USA300 MRSA; and 101 residents developed MRSA infection. The risk of infection was twofold higher in residents colonized with USA300 MRSA compared to residents not colonized with MRSA [adjusted hazard ratio 2·3, 95% confidence interval (CI) 1·1-4·5]. The risk of infection in USA300 MRSA-colonized residents was similar to USA300 MRSA non-colonized residents (relative risk 1·1, 95% CI 0·5-2·3). Our findings show that colonization with USA300 MRSA increases the risk of MRSA infection suggesting a similar pathogenesis.

Update on resistance of Bacteroides fragilis group and related species with special attention to carbapenems 2006-2009.

The susceptibility trends for the species of the Bacteroides fragilis group against various antibiotics were determined using data from 4 years [2006-2009] on 1957 isolates referred by 8 medical centers participating in a National Survey for the Susceptibility of B. fragilis. The antibiotic test panel included doripenem, ertapenem, imipenem, meropenem, ampicillin:sulbactam, piperacillin:tazobactam, cefoxitin, clindamycin, moxifloxacin, tigecycline, chloramphenicol and metronidazole. MICs were determined using agar dilution methods following CLSI recommendations. Genetic analysis of isolates from 2008 with elevated MICs (>2 µg/mL) to one or more of the carbapenems to detect presence of the cfiA gene was performed using PCR methodology. The results showed an increase in the resistance rates to the ß-lactam antibiotics. High resistance rates were seen for clindamycin and moxifloxacin (as high as 60% for clindamycin and >80% for moxifloxacin), with relatively stable low resistance (5.4%) for tigecycline. For carbapenems, resistance in B. fragilis was 1.1%-2.5% in 2008-9. One isolate resistant to metronidazole (MIC 32 µg/mL) was observed as well as isolates with elevated MICs to chloramphenicol (16 µg/mL). Genetic analysis indicated that the cfiA gene was present in some but not all of the isolates with high MICs to the carbapenems. These data indicate that there continue to be changes in susceptibility over time, and that resistance can be seen among the carbapenems. High antibiotic resistance rates tend to be associated with specific species.

Comparison of culture media for detection of Acinetobacter baumannii in surveillance cultures of critically-ill patients.

The objective of this study was to evaluate the performance of CHROMagar Acinetobacter when compared to sheep blood agar, MacConkey agar and MacConkey agar with 6 µg/ml of imipenem for the detection of A. baumannii in surveillance cultures of hospitalized patients. We utilized peri-anal swabs and sputum samples from patients admitted to the University of Maryland Medical Center ICUs from December 7 through December 21, 2009. Samples were plated onto four media in the following order: (1) 5% sheep blood agar (SBA), (2) MacConkey agar, (3) MacConkey agar with 6 µg/ml of imipenem, and (4) CHROMagar Acinetobacter (CHROMagar). SBA was the gold standard to which all media was compared. There were 165 samples collected during the study period. SBA and CHROMagar detected 18 of 18 (100%) Acinetobacter and 11 of 11 (100%) MDR-A. baumannii. MacConkey agar detected 16 of 18 (89%) Acinetobacter and 10 of 11 (91%) MDR- A. baumannii while MacConkey agar with 6 µg/ml imipenem detected 9 of 11 (82%) MDR-A. baumannii. CHROMagar did not differentiate MDR- A. baumannii from non-MDR-A. baumannii. CHROMagar may be useful for rapid detection of patients with MDR-A. baumannii if improved upon to better select for MDR-A. baumannii.

Linfangioma mesentérico multiquístico como causa de vólvulo intestinal / Mesenteric lymphangioma causing volvulus: report of one case

Lymphangiomas are rare benign lesions, most commonly seen in children and adolescents. Their intra-abdominal presentation is uncommon. We report a 19 years old male, presenting to the emergency room with abdominal pain associated with fever, vomiting and abdominal distension. There was a history of multiple previous consultations for abdominal pain. A plain abdominal X-ray examination suggested a bowel obstruction. At surgery a volvulus and dilation of the small bowel in relation to a vascular malformation was found, excising 40 cm of jejunum with an end-to-end intestinal anastomosis. The pathology report showed a Mesenteric Multicystic Lymphangioma. Presently, the patient is in good conditions.

Los linfangiomas son lesiones benignas, de baja incidencia, más comunes en niños y adolescentes. Con muy baja frecuencia son intraabdominales y poseen presentación clínica variable, yendo desde el hallazgo clínico hasta pacientes con riesgo vital por abdomen agudo. Presentamos el caso de un paciente de 19 años, sin antecedentes mórbidos que acude a urgencias por dolor abdominal asociado a fiebre, vómitos y distensión abdominal; la radiografía simple es sugerente de obstrucción intestinal. En laparotomía exploradora se encuentra un vólvulo y dilatación del intestino delgado en relación a una malformación vascular y lesiones multilobuladas en mesenterio. Se resecan 40 cm de yeyuno y realiza anastomosis término-terminal. La histología reveló un Linfangioma Multiquístico Mesentérico. El paciente evoluciona en buenas condiciones generales y se mantiene control clínico e imagenológico seriado. Aunque infrecuente, es uno de los diagnósticos diferenciales de abdomen agudo. A pesar de su naturaleza benigna puede llegar a comprometer el pronóstico vital del paciente.

Bladder endometriosis: laparoscopic treatment and follow-up.

OBJECTIVES: This study aims to show the treatment outcome in women affected by isolated bladder endometriosis who underwent laparoscopic surgery in our units. Only women with deep nodules located in the bladder were selected, thus excluding women with deep lesions located in other sites. STUDY DESIGN: Between March 2005 and 2007, women with deep vesical endometriosis, referring to the Departments of Obstetrics and Gynaecology of University Hospitals "G. Martino"of Messina, "Paolo Giaccone"of Palermo and "San Paolo"of Milano, were respectively recruited. A preoperative assessment of the pathology was performed. Women who were concomitantly diagnosed deep nodules of the rectovaginal septum and/or endometriotic ovarian cysts were excluded. A medical therapy with oral contraceptive and/or GnRH analogues was first proposed to the patients affected. If medical treatment failed, a laparoscopic treatment was suggested. We performed a segmental resection of the involved wall or an extramucosal dissection of the bladder according to the cases. A clinical and an instrumental evaluation by ultrasound was performed every 6 months after surgery for the first year and subsequently every 12 months. At the time of referral, patients were also questioned about any recurrence of symptoms. RESULTS: Eight women, with a mean age of 33.8 (range 30-37 years; S.D.=2.5) and a mean parity of 1 (range 0-2) were recruited. Medical therapy failed in all cases and the women underwent laparoscopic treatment. Surgery was complete in all cases without a need for ureteral cannulation. No intraoperative complications occurred. The mean estimated blood loss was 98 ml (range 40-200 ml). All patients underwent at least the first follow-up assessment. In none of the women, recurrence of bladder endometriotic nodules was documented. In contrast, urinary symptoms were reported in three cases. Nevertheless, all the patients reported improvement of symptoms and declared to be satisfied. CONCLUSIONS: We recommend surgical eradication of bladder lesions. Laparoscopic treatment, in the hands of an expert surgeon, is the management of choice. It offers the best approach to the diagnosis allowing good long-term results, with a less invasive approach. Large multicentric studies are however required prior to drawing definite conclusions.

National survey on the susceptibility of Bacteroides fragilis group: report and analysis of trends in the United States from 1997 to 2004.

The susceptibility trends for the species of the Bacteroides fragilis group against various antibiotics from 1997 to 2004 were determined by using data for 5,225 isolates referred by 10 medical centers. The antibiotic test panel included ertapenem, imipenem, meropenem, ampicillin-sulbactam, piperacillin-tazobactam, cefoxitin, clindamycin, moxifloxacin, tigecycline, chloramphenicol, and metronidazole. From 1997 to 2004 there were decreases in the geometric mean (GM) MICs of imipenem, meropenem, piperacillin-tazobactam, and cefoxitin for many of the species within the group. B. distasonis showed the highest rates of resistance to most of the beta-lactams. B. fragilis, B. ovatus, and B. thetaiotaomicron showed significantly higher GM MICs and rates of resistance to clindamycin over time. The rate of resistance to moxifloxacin of B. vulgatus was very high (MIC range for the 8-year study period, 38% to 66%). B. fragilis, B. ovatus, and B. distasonis and other Bacteroides spp. exhibited significant increases in the rates of resistance to moxifloxacin over the 8 years. Resistance rates and GM MICs for tigecycline were low and stable during the 5-year period over which this agent was studied. All isolates were susceptible to chloramphenicol (MICs < 16 microg/ml). In 2002, one isolate resistant to metronidazole (MIC = 64 microg/ml) was noted. These data indicate changes in susceptibility over time; surprisingly, some antimicrobial agents are more active now than they were 5 years ago.

Peptide nucleic acid fluorescence in situ hybridization-based identification of Candida albicans and its impact on mortality and antifungal therapy costs.

The impact of rapid identification of Candida albicans blood isolates by peptide nucleic acid fluorescence in situ hybridization (PNA FISH) on the selection and expenditure of antifungal therapy was evaluated. PNA FISH was 100% sensitive and specific in the rapid identification of 31 out of 72 candidemias as C. albicans and resulted in a significant reduction of caspofungin usage, with an overall cost savings of 1,729 US dollars per patient.

In vitro activities of newer quinolones against bacteroides group organisms.

The activities of BMS-284576, clinafloxacin, moxifloxacin, sitafloxacin, trovafloxacin, imipenem, cefoxitin, and clindamycin against 589 Bacteroides fragilis group isolates were determined. The activity of BMS-284576 was comparable to that of trovafloxacin. Sitafloxacin and clinafloxacin were the most active quinolones, and moxifloxacin was the least active. B. fragilis was the most susceptible of the species, and Bacteroides vulgatus was the most resistant. Association of specific antibiotic resistance with Bacteroides species was noted for all quinolones.

National survey on the susceptibility of Bacteroides Fragilis Group: report and analysis of trends for 1997-2000.

The results of a multicenter US survey using the National Committee for Clinical Laboratory Standards currently recommended methodology for measuring in vitro susceptibility of 2673 isolates of Bacteroides fragilis group species were compared from 1997 to 2000. The test panel consisted of 14 antibiotics: 3 carbapenems, 3 beta-lactam-beta-lactamase inhibitors, 3 cephamycins, 2 fluoroquinolones, clindamycin, chloramphenicol, and metronidazole. Declines in the geometric mean minimum inhibitory concentrations were seen with imipenem, meropenem, ampicillin-sulbactam, and the cephamycins. Increased geometric means were observed with the fluoroquinolones and were usually accompanied by an increase in resistance rates. Bacteroides distasonis shows the highest resistance rates among beta-lactam antibiotics, whereas Bacteroides vulgatus shows the highest resistance levels among fluoroquinolones. B. fragilis shows the lowest resistance rates for all antibiotics. All strains were susceptible to chloramphenicol and metronidazole concentrations <8 microgram/mL. The data underscore the need for species identification and continued surveillance to monitor resistance patterns.

The impact of an enteroviral RT-PCR assay on the diagnosis of aseptic meningitis and patient management.

BACKGROUND: Enterovirus (EV) is a major cause of aseptic meningitis and non-specific febrile illness in children. Since the majority of patients are hospitalized for possible bacterial infection, a rapid test for the diagnosis of enteroviral meningitis (EVM) may reduce hospitalizations and unnecessary treatments. OBJECTIVE: To review the impact of an EV reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the diagnosis of EVM on patient management. STUDY DESIGN: CSF from 1056 patients admitted to the hospital between 1998 and 2001 was tested using EV RT-PCR. The results were correlated with CSF counts, diagnosis, test turnaround time (TAT) and length of hospital stay (LOS). RESULTS: EV RT-PCR was positive for 113 patients (11%). Of these cases, 92% occurred during the summer months and 77% were in children <19 years of age. Children <3 years old with EVM frequently had non-specific clinical findings and lacked pleocytosis. There was a significant correlation between decreasing LOS and TAT (r(2)=0.97, P<0.001). CONCLUSION: RT-PCR testing for EVM is an important tool to aid in the diagnosis of children with non-specific febrile illness. This test impacted patient management as measured by shortened patient stays, which should translate into significant health care savings.

Selection of high-level oxacillin resistance in heteroresistant Staphylococcus aureus by fluoroquinolone exposure.

To study the effect of fluoroquinolone exposure on the expression of mec(A)-encoded oxacillin resistance, population analysis profiling was performed on four strains of fluoroquinolone-susceptible, mec(A)-positive, heteroresistant Staphylococcus aureus. Growth in the presence of 0.5 x MIC of a fluoroquinolone resulted in >10-fold increase in the proportion of the population that grew on agar containing oxacillin 128 mg/L. Ciprofloxacin exhibited a greater effect than moxifloxacin, levofloxacin and gatifloxacin (average 3400-, 220-, 170- and 49-fold increase in oxacillin-resistant colonies versus the control, respectively). The increase was directly proportional to the fluoroquinolone concentration and could be detected as early as 8 h after exposure to the fluoroquinolone. At 8 h, the absolute number of colonies that grew on oxacillin 128 mg/L was similar whether or not the isolate was exposed to the fluoroquinolone, but the total cfu on non-selective media decreased. The resultant oxacillin-resistant colonies also showed a 1.5- to 3-fold increase in fluoroquinolone MIC. No oxacillin resistance was observed on two similarly treated fluoroquinolone-susceptible, mec(A)-negative strains. It appears that fluoroquinolones influence oxacillin resistance by selective inhibition or killing of the more susceptible subpopulations in heteroresistant S. aureus. The surviving populations are more resistant to both oxacillin and fluoroquinolone. The mechanisms of resistance to the two agents may be unrelated but tend to be associated. This could explain in part the observed increases in fluoroquinolone-resistant MRSA.

Risk factors for surgical-site infections following cesarean section.

OBJECTIVE: To identify risk factors associated with surgical-site infections (SSIs) following cesarean sections. DESIGN: Prospective cohort study. SETTING: High-risk obstetrics and neonatal tertiary-care center in upstate New York. PATIENTS: Population-based sample of 765 patients who underwent cesarean sections at our facility during 6-month periods each year from 1996 through 1998. METHODS: Prospective surgical-site surveillance was conducted using methodology of the National Nosocomial Infections Surveillance System. Infections were identified during admission, within 30 days following the cesarean section, by readmission to the hospital or by a postdischarge survey. RESULTS: Multiple logistic-regression analysis identified four factors independently associated with an increased risk of SSI following cesarean section: absence of antibiotic prophylaxis (odds ratio [OR], 2.63; 95% confidence interval [CI95], 1.50-4.6; P=.008); surgery time (OR, 1.01; CI95, 1.00-1.02; P=.04); <7 prenatal visits (OR, 3.99; CI95, 1.74-9.15; P=.001); and hours of ruptured membranes (OR, 1.02; CI95, 1.01-1.03; P=.04). Patients given antibiotic prophylaxis had significantly lower infection rates than patients who did not receive antibiotic prophylaxis (P=02), whether or not active labor or ruptured membranes were present. CONCLUSION: Among the variables identified as risk factors for SSI, only two have the possibility to be changed through interventions. Antibiotic prophylaxis would benefit all cesarean patients regardless of active labor or ruptured membranes and would decrease morbidity and length of stay. Women's healthcare professionals also must continue to encourage pregnant women to start prenatal visits early in the pregnancy and to maintain scheduled visits throughout the pregnancy to prevent perinatal complications, including postoperative infection.

Nucleotide sequence of the chromosomal ampC gene of Enterobacter aerogenes.

The AmpC beta-lactamase gene and a small portion of the regulatory ampR sequence of Enterobacter aerogenes 97B were cloned and sequenced. The beta-lactamase had an isoelectric point of 8 and conferred cephalosporin and cephamycin resistance on the host. The sequence of the cloned gene is most closely related to those of the ampC genes of E. cloacae and C. freundii.

Long-term control of Legionella species in potable water after a nosocomial legionellosis outbreak in an intensive care unit.

Environmental and patient-care control measures were initiated in response to an outbreak of legionellosis in an intensive care unit in 1992. The measures included maintaining elevated potable hot-water temperatures following superheating and using sterile water for administrations through nasogastric tubes. Legionella species remained below detectable levels in the potable hot-water system upon reevaluation in 1999. Nosocomial cases of legionellosis have not been reported since the outbreak.

A one-step RT-PCR assay using an enzyme-linked detection system for the diagnosis of enterovirus meningitis.

BACKGROUND: Enteroviruses are the most common cause of meningitis in the United States, with an estimated 50000-75000 cases each year. Enteroviral meningitis (EVM) is frequently a diagnosis of exclusion, as viral cultures lack sensitivity and require prolonged incubation periods. OBJECTIVE: To develop a sensitive and rapid test for the diagnosis of EVM. STUDY DESIGN: A rapid, one-step, reverse transcriptase-polymerase chain reaction (RT-PCR) was used in a prospective analysis of 160 patients who had cerebrospinal fluid (CSF) tested for enterovirus. RESULTS: Of the 160 patients, 14 were excluded due to missing CSF viral culture data. A total of 14 were CSF culture positive (10 with pleocytosis) and 19 were PCR positive (15 with pleocytosis). The ability to detect enterovirus by either culture or PCR correlated significantly with the white blood cell count in the CSF (P=0.001). Based on a clinical definition of enterovirus culture positive and pleocylosis: ten had definite EVM and 12 had probable EVM (pleocytosis without any other cause). Four had possible EVM (CSF culture positive without pleocytosis) and 18 had pleocytosis due to other causes. PCR was positive in all ten patients with definite EVM. Five out of 12 patients with probable EVM and three out of four patients with possible EVM. No patients with pleocytosis due to other causes were PCR positive and one patient that was defined as EVM negative (culture negative and no pleocytosis) was PCR positive. Overall, PCR was positive in 18 out of the 26 patients with a likelihood of EVM, while CSF culture was positive in only 14 cases. Our results demonstrated that RT-PCR enhances the sensitivity of enterovirus detection in CSF (69 vs. 54% for culture). CONCLUSION: The diagnosis of EVM is difficult to make clinically: the enhanced sensitivity and rapid turn around time of PCR will be of great clinical benefit.

Nucleotide sequence of a 7-kb fragment of pACM1 encoding an IncM DNA primase and other putative proteins associated with conjugation.

A 7-kb fragment of pACM1 (fragment 90¿91) containing one or more kor (kill-override) loci was sequenced, and 28 open reading frames (ORFs; >/=50 codons) were identified. The nucleotide sequence has no significant homologs in the GenBank database except for a 1.3-kb region 98.6% identical to the iml (insensitivity to phage PhiM-mediated lysis) determinant fragment of IncM plasmid R446. Deduced amino acid sequences for several ORFs are homologous to those of known proteins, including the Sog DNA primases of IncI1 plasmids R64 and ColIb-P9 and the TraL, TraM, and TraN products of ColIb-P9. Two protein products of the putative primase ORF (ORF 1, 1100 amino acids) were detected by SDS-PAGE. The 158- and 107-kDa proteins were designated PriL and PriS, respectively. PriS is apparently produced by an in-frame reinitiation of the ORF 1 transcript at a second start codon located between a Sau96I site and a PstI site. The motif EGYATA, conserved among primases and associated with primase function, occurs in the first one-third of the deduced amino acid sequence of PriL and is not included in PriS. Partial suppression of the temperature-sensitive dnaG3 mutation in BW86 was demonstrated by recombinants that overexpressed both PriL and PriS, but not by constructs overexpressing only PriS. Therefore, primase function can be assigned to PriL. Fragment 90/91 represents a portion of the IncM tra region, which has not previously been examined in detail.

Vancomycin and oxacillin synergy for methicillin-resistant staphylococci.

An increase in oxacillin activity was observed against methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-resistant Staphylococcus aureus (MRSA) in the presence of a sub-MIC of vancomycin. Vancomycin and oxacillin were synergistic against 14 of 21 strains of MRCNS and MRSA. A pattern of enhanced killing was also supported by time-kill studies. These results suggest that combinations of sub-MICs of vancomycin and oxacillin may have therapeutic benefits against methicillin-resistant staphylococci.

Evaluation of an antiseptic triple-lumen catheter in an intensive care unit.

OBJECTIVE: To evaluate a decrease in catheter-related bloodstream infection rate in patients with antiseptic triple-lumen catheters in an intensive care unit. DATA SOURCES: Retrospective review of surveillance records, patient medical records, laboratory and microbiological reports, and antibiotic administration records. STUDY SELECTION: Patients admitted to the intensive care unit with triple-lumen catheters. DATA EXTRACTION: A subset of one entry per patient was extracted from 2 yrs of primary bloodstream infection surveillance data. Data collection included risk factors, laboratory and microbiological data, and insertion sites and dates of all intravascular catheters present during triple-lumen catheterization. DATA SYNTHESIS: The catheter-related bloodstream infection rate was 5.4 and 11.3 per 1000 catheter days in antiseptic and nonantiseptic triple-lumen catheter groups, respectively (p = .06). By multivariate analysis using a Cox Proportional Hazards Model, the antiseptic triple-lumen catheters were associated with a significant reduction in catheter-related bloodstream infection (p = .03). Model expansion to include intrajugular site was significant by a likelihood ratio test [2(log likelihood diff) = 4.26 P<.05 chi2(1)] CONCLUSIONS: The use of antiseptic triple-lumen catheters may substantially reduce catheter-related bloodstream infections in an intensive care population and may be subsequently associated with a decrease in length of stay.

Total laparoscopic hysterectomy versus total abdominal hysterectomy: an assessment of the learning curve in a prospective randomized study.

The present randomized study was undertaken in order to compare the short-term results between total laparoscopic hysterectomy and abdominal hysterectomy in a centre with experience in laparoscopic surgery. From January 1997 to September 1998 inclusive, 102 women aged 44-71 years were randomly assigned to either total laparoscopic hysterectomy (n = 51 patients) or abdominal hysterectomy (n = 51 patients). The patients' demographic characteristics were similar in both groups. Average intra-operative blood loss was lower in laparoscopic hysterectomy than in abdominal hysterectomy (P