Oxacillin Resistance and Antimicrobial Susceptibility Profile of Staphylococcus saprophyticus and Other Staphylococci Isolated from Patients with Urinary Tract Infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Human respiratory syncytial virus in children hospitalized for acute lower respiratory infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular fingerprinting methods for the discrimination between C-albicans and C-dubliniensis

Opportunistic fungal pathogens are becoming increasingly important causes of both community-acquired and nosocomial infections. The most important fungal pathogens are yeast species belonging to the genus Candida. These species show differences in levels of resistance to antifungal agents and mortality. Consequently, it is important to correctly identify the causative organism to the species level. Identification of Candida dubliniensis in particular remains problematic because of the high degree of phenotypic similarity between this species and Candida albicans. However, as the differences between both are most pronounced at the genetic level, several studies have been conducted in order to provide a specific and rapid identification fingerprinting molecular test. In most candidal infectious, no single DNA fingerprinting technique has evolved as a dominant method, and each method has its advantages, disadvantages and limitations. Moreover, the current challenge of these techniques is to compile standardized patterns in a database for interlaboratory use and future reference. This review provides an overview of most common molecular fingerprinting techniques currently available for discrimination of C. albicans and C. dubliniensis.

Ocorrência de infecção urinária em pacientes de um hospital universitário

Infection in hospitals is a serious problem for the Public Health System. It is responsible for the increasing number of hospital deaths, as well as the longer time patients may have to stay in hospital, raising the costs of confinement more and more. The most common hospital infection is urinary tract infections (UTI), the use of the urinary catheter being the main risk factor. The aim of this study was to evaluate the profile of UTI among hospitalized patients in a University Hospital in Brazil, from October to December 2003. Out of 271 samples of urine checked, 51 were positive, 27 of these from patients having community-acquired UTI and 24 whose infection originated in the hospital. The community-acquired UTIs were more frequent in female patients (63%). The highest incidence of infection was caused by Escherichia coli (74%), especially in patients aged from 0 to 15 (37%). The episodes of hospital-acquired infection happened, in the main, in male patients aged above 50 (68%) who were using a lasting vesical catheter; in this group of patients the infection was frequently caused by E. coli (29.1%) and Klebsiella spp. (29.1%). E. coli and Klebsiella pneumoniae exhibited strong resistance (62.5%) to trimethoprim-sulfamethoxazole, as well as to ampicillin, showing that these drugs should not be used to cure UTIs in this institution.

Isolamento e caracterização de amostras comunitárias Staphylococcus aureus resistente à Meticilina (CA-MRSA) em uma população carcerária no município de Avaré

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Staphylococcal enterotoxins: molecular aspects and detection methods

Members of the Staphylococcus genus, especially Staphylococcus aureus, are the most common pathogens found in hospitals and in community-acquired infections. Some of their pathogenicity is associated with enzyme and toxin production. Until recently, S. aureus was the most studied species in the genus; however, in last few years, the rise of infections caused by coagulase-negative staphylococci has pointed out the need for further studies on virulence factors that have not yet been completely elucidated so as to better characterize the pathogenic potential of this group of microorganisms. Several staphylococcal species produce enterotoxins, a family of related proteins responsible for many diseases, such as the toxic-shock syndrome, septicemia and food poisoning. To this date, 23 different enterotoxin types have been identified besides toxic-shock syndrome toxin-1 (TSST-1), and they can be divided into five phylogenetic groups. The mechanism of action of these toxins includes superantigen activity and emetic properties, which can lead to biological effects of infection. Various methods can detect genes that encode enterotoxins and their production. Molecular methods are the most frequently used at present. This review article has the objective to describe aspects related to the classification, structure and regulation of enterotoxins and toxic-shock syndrome toxin-1 detection methods.

Molecular epidemiology of extended-spectrum-beta-lactamase-producing Klebsiella pneumoniae over a 10 year period in Calgary, Canada

A study was designed to investigate the molecular epidemiology of extended-spectrum -lactamase (ESBL)-producing Klebsiella pneumoniae isolated in a centralized region over a 10 year period (200009). Molecular characterization was done using isoelectric focusing, PCR and sequencing for bla(CTX-M), bla(TEM) and bla(SHV) genes and plasmid-mediated quinolone resistance determinants. Genetic relatedness was determined with PFGE using XbaI and multilocus sequencing typing. A total of 89 patients with incident infections were identified; the majority presented with hospital-onset urinary tract infections. The absolute number of ESBL-producing isolates remained very low until 2003, increased slightly in 2004, remained stable until 2008 and then in 2009 there was an abrupt increase in the numbers of ESBL producers identified. The majority of K. pneumoniae produced CTX-M-14 and -15, and have replaced SHV-12-producing isolates since 2005. We identified four different major sequence types (STs) among 32 of isolates (i.e. ST17, ST20, and the new ST573 and ST575) and provided insight into their clinical and molecular characteristics. The ST isolates were more likely to produce community-onset infections, were associated with bla(CTX-M) and emerged during the latter part of the study period. ST17 produced CTX-M-15 and SHV-12, and was more likely to be positive for qnrB; ST20 produced CTX-M-14 and was positive for qnrS. The multiresistant ST575 that produced CTX-M-15 appeared in 2009. Our study highlights the importance of molecular epidemiology in providing insight into the emergence, characteristics and distribution of STs among ESBL-producing K. pneumoniae.

Complicated intra-abdominal infections in Europe: a comprehensive review of the CIAO study

The CIAO Study ("Complicated Intra-Abdominal infection Observational" Study) is a multicenter investigation performed in 68 medical institutions throughout Europe over the course of a 6-month observational period (January-June 2012).Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.2,152 patients with a mean age of 53.8 years (range: 4-98 years) were enrolled in the study. 46.3% of the patients were women and 53.7% were men. Intraperitoneal specimens were collected from 62.2% of the enrolled patients, and from these samples, a variety of microorganisms were collectively identified.The overall mortality rate was 7.5% (163/2.152).According to multivariate analysis of the compiled data, several criteria were found to be independent variables predictive of patient mortality, including patient age, the presence of an intestinal non-appendicular source of infection (colonic non-diverticular perforation, complicated diverticulitis, small bowel perforation), a delayed initial intervention (a delay exceeding 24 hours), sepsis and septic shock in the immediate post-operative period, and ICU admission.Given the sweeping geographical distribution of the participating medical centers, the CIAO Study gives an accurate description of the epidemiological, clinical, microbiological, and treatment profiles of complicated intra-abdominal infections (IAIs) throughout Europe.

Complicated intra-abdominal infections in Europe: preliminary data from the first three months of the CIAO Study

The CIAO Study is a multicenter observational study currently underway in 66 European medical institutions over the course of a six-month study period (January-June 2012).This preliminary report overviews the findings of the first half of the study, which includes all data from the first three months of the six-month study period.Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.912 patients with a mean age of 54.4 years (range 4-98) were enrolled in the study during the first three-month period. 47.7% of the patients were women and 52.3% were men. Among these patients, 83.3% were affected by community-acquired IAIs while the remaining 16.7% presented with healthcare-associated infections. Intraperitoneal specimens were collected from 64.2% of the enrolled patients, and from these samples, 825 microorganisms were collectively identified.The overall mortality rate was 6.4% (58/912). According to univariate statistical analysis of the data, critical clinical condition of the patient upon hospital admission (defined by severe sepsis and septic shock) as well as healthcare-associated infections, non-appendicular origin, generalized peritonitis, and serious comorbidities such as malignancy and severe cardiovascular disease were all significant risk factors for patient mortality.White Blood Cell counts (WBCs) greater than 12,000 or less than 4,000 and core body temperatures exceeding 38°C or less than 36°C by the third post-operative day were statistically significant indicators of patient mortality.

Population-based epidemiology of rotavirus hospitalisations in Switzerland

BACKGROUND: Rotaviruses (RV) are the most common cause of dehydrating gastroenteritis requiring hospitalisation in children <5 years of age. A new generation of safe and effective RV vaccines is available. Accurate data describing the current burden of RV disease in the community are needed to devise appropriate strategies for vaccine usage. METHODS: Retrospective, population-based analysis of RV hospitalisations in children <5 years of age during a 5-year period (1999-2003) in a both urban and rural area inhabited by 12% of the Swiss population. RESULTS: Of 406 evaluable cases, 328 were community-acquired RV infections in children <5 years of age. RV accounted for 38% of all hospitalisations for gastroenteritis. The overall hospitalisation incidence in the <5-year-old was 1.5/1000 child-years (peak incidence, 2.6/1000 child-years in children aged 13-24 months). The incidence of community-acquired RV hospitalisations was significantly greater in children of non-Swiss origin (3.0 vs. 1.1/1000 child-years, relative risk 2.7; 95% CI 2.2-3.4), who were younger, but tended to be less severely dehydrated on admission than Swiss children. In comparison with children from urban areas, RV hospitalisation incidence was significantly lower among those residing in the remote mountain area (0.71 vs. 1.71/1000 child years, relative risk 2.2, 95% CI 1.6-3.1). CONCLUSION: Population-based RV hospitalisation incidence was low in comparison with other European countries. Significantly greater hospitalisation rates among children living in urban areas and those from non-Swiss families indicate that factors other than the severity of RV-induced dehydration are important driving forces of hospital admission.

Nosocomial infection: A risk factor for a complicated course in children with respiratory syncytial virus infection - Results from a prospective multicenter German surveillance study

BACKGROUND: Nosocomially acquired respiratory syncytial virus infections (RSV-NI) may cause serious problems in hospitalized paediatric patients. Hitherto, prospectively collected representative data on RSV-NI from multicenter studies in Germany are limited. METHODS: The DMS RSV Ped database was designed for the prospective multicenter documentation and analysis of clinically relevant aspects of the management of inpatients with RSV-infection. The study covered six consecutive seasons (1999-2005); the surveillance took place in 14 paediatric hospitals in Germany. RESULTS: Of the 1568 prospectively documented RSV-infections, 6% (n=90) were NI and 94% (n=1478) were community acquired (CA). A significantly higher proportion in the NI group displayed additional risk factors like prematurity, chronic lung disease, mechanical ventilation (med. history), congenital heart disease, and neuromuscular impairment. Of all NI, 55% occurred in preterms (30.6% of all RSV-infections in preterms with severe chronic lung disease of prematurity were NI). Illness severity as well as the total mortality, but not the attributable mortality was significantly higher in the NI group. In the multivariate analysis, NI was significantly associated with the combined outcome 'complicated course of disease'. CONCLUSION: This is the first prospective multicenter study from Germany, which confirms the increased risk of a severe clinical course in nosocomially acquired RSV-infection. Of great concern is the high rate of (preventable) NI in preterms, in particular in those with severe chronic lung disease or with mechanical ventilation due to other reasons.

Significance of Staphylococcus lugdunensis bacteremia: report of 28 cases and review of the literature

BACKGROUND: Staphylococcus lugdunensis endocarditis has been associated with an aggressive course. The aim of this study was to determine factors associated with the development of endocarditis in patients with S. lugdunensis bacteremia. METHODS: A retrospective analysis of all patients with S. lugdunensis bacteremia in three tertiary care centers in Switzerland was performed. Data regarding medical history, symptoms, and susceptibility of S. lugdunensis isolates were collected. Our results were reviewed in the context of the current literature. RESULTS: A total of 28 patients with S. lugdunensis bacteremia were identified. Of the 13 patients with endocarditis, all were community acquired. Cardiac surgery was performed in 85% of these patients; mortality was 23%, reflecting the aggressive course of this disease. In contrast, in the 15 patients without endocarditis, no complications associated with S. lugdunensis bacteremia were observed. In 73%, a probable source was identified in the form of a venous catheter or other foreign device. Only three of these episodes were community acquired. No difference was observed in susceptibility of the S. lugdunensis isolates to penicillin, which was 77% in endocarditis isolates, and 87% in isolates of bacteremia without endocarditis, respectively. CONCLUSION: S. lugdunensis bacteremia is associated with endocarditis in up to 50% of patients. Every patient with community-acquired S. lugdunensis bacteremia should be carefully examined for signs of endocarditis. Once S. lugdunensis endocarditis is diagnosed, close monitoring is essential and surgical treatment should be considered early. In the nosocomial setting, endocarditis is far less frequent, and S. lugdunensis bacteremia is usually associated with a catheter or other foreign materials.

[Antibiotic therapy in the outpatient setting: update 2009]

Rational outpatient therapy restricts antibiotics to infections where they are beneficial and selects substances based on local resistance patterns. Respiratory tract infections typically caused by viruses should not be treated with antibiotics (e.g., rhinitis, bronchitis, sinusitis). Many respiratory infections likely caused by bacteria can be treated with aminopenicillin, sometimes combined with a beta-lactamase inhibitor. Quinolones should be used only as exception for respiratory tract infections, since resistance is rising. For this reason uncomplicated urinary tract infections (cystitis) should be treated with trimethoprim-sulfa-methoxazole (TMP-SMX) instead of quinolones, even though approximately 20% of Escherichia coli are resistant to TMP-SMX. Skin and soft tissue infections are best treated with beta-lactam antibiotics, as long as the community acquired methicillin-resistant strains of S. aureus frequently seen in certain countries remain uncommon here.

A 4-year study on clinical characteristics of children hospitalized with rotavirus gastroenteritis

Rotavirus (RV) is a frequent cause of severe gastroenteritis (GE) in children. With the licensure of new RV vaccines, data on the burden of disease are important regarding immunization strategies. We reviewed the medical records of children hospitalized with RV infection in our institution between July 2002 and March 2006. Relevant data were extracted in a standardized fashion from records of hospitalized children with a positive RV antigen test in a stool sample. Severity of disease was graded by the 20-point Vesikari score. Population data were obtained from the Federal Office of Statistics. Six hundred eighty-six RVGE were identified and records of 608 hospitalizations (in 607 children) were available. In 539 (89%) cases, RVGE was the primary reason for hospitalization and 69 (11%) were nosocomial infections; yearly peaks occurred between February and May. Cumulative incidence of RVGE was 26.7/1,000 children <3 years of age. Median age of 539 children (55.6% male) with primary RVGE was 1.4 years and median stay in the hospital for both community acquired and nosocomial RVGE was 4 days (interquartile range 3-5). Thirtypercent and 94% of RV hospitalizations were in children <1 and <3 years of age, respectively. Mean Vesikari score was 15 (range 6-20; 96% >11). Intravenous fluids were administered in 378 (70%) patients, 130 (24%) patients were rehydrated via nasogastral tube, and 31 (5.7%) received rehydration by mouth. RVGE causes a substantial burden in children with an estimated risk for hospitalization due to RVGE of one in 37 children <3 years of age.

Patient characteristics but not virulence factors discriminate between asymptomatic and symptomatic E. coli bacteriuria in the hospital

Background Escherichia coli is a common cause of asymptomatic and symptomatic bacteriuria in hospitalized patients. Asymptomatic bacteriuria (ASB) is frequently treated with antibiotics without a clear indication. Our goal was to determine patient and pathogen factors suggestive of ASB. Methods We conducted a 12-month prospective cohort study of adult inpatients with E. coli bacteriuria seen at a tertiary care hospital in St. Louis, Missouri, USA. Urine cultures were taken at the discretion of treating physicians. Bacterial isolates were tested for 14 putative virulence genes using high-throughput dot-blot hybridization. Results The median age of the 287 study patients was 65 (19–101) years; 78% were female. Seventy percent had community-acquired bacteriuria. One-hundred ten (38.3%) patients had ASB and 177 (61.7%) had symptomatic urinary tract infection (sUTI). Asymptomatic patients were more likely than symptomatic patients to have congestive heart failure (p = 0.03), a history of myocardial infarction (p = 0.01), chronic pulmonary disease (p = 0.045), peripheral vascular disease (p = 0.04), and dementia (p = 0.03). Patients with sUTI were more likely to be neutropenic at the time of bacteriuria (p = 0.046). Chronic pulmonary disease [OR 2.1 (95% CI 1.04, 4.1)] and dementia [OR 2.4 (95% CI 1.02, 5.8)] were independent predictors for asymptomatic bacteriuria. Absence of pyuria was not predictive of ASB. None of the individual virulence genes tested were associated with ASB nor was the total number of genes. Conclusions Asymptomatic E. coli bacteriuria in hospitalized patients was frequent and more common in patients with dementia and chronic pulmonary disease. Bacterial virulence factors could not discriminate symptomatic from asymptomatic bacteriurias. Asymptomatic E. coli bacteriuria cannot be predicted by virulence screening.