Background: The purpose of this study is to compare the effect of different systems for eliminating duplicates in order to optimize the calculation of the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection. Methods: We compare the Clinical and Laboratory Standards Institute (CLSI) criterion, time criteria and the criterion recommended by the European Antimicrobial Surveillance System (EARSS). Results: Multiple isolates of MRSA are frequently recovered from successive cultures from the same patient (the average isolation rate of MRSA is 2.72), which demonstrates the importance of eliminating duplicates. When CLSI criterion data are compared to those obtained using other criteria, a significant increase in the number of S. aureus isolates was found applying time criteria (up to 36%) or the EARSS criterion (13%). There is also an increase in the methicillin resistance rate (between 3.31 and 3.96%; p < 0.01). Conclusions: We believe that the EARSS method, with the proper quality controls and latest software tools available, is the best for determining the true situation of MRSA.

The aim of this study was to determine the diagnostic usefulness of quantification of the H. pylori genome in detection of infection in patients with upper gastrointestinal bleeding (UGB). A total of 158 consecutive patients with digestive disorders, 80 of whom had clinical presentation of UGB, were studied. The number of microorganisms was quantified using a real-time PCR system which amplifies the urease gene with an internal control for eliminating the false negatives. A biopsy sample from the antrum and corpus of each patient was processed. The rapid urease test, culture, histological study, stool antigen test, and breath test were done. The gold standard was a positive culture or positive results in at least two of the other techniques. When a positive result was defined as any number of microorganisms/human cell, the sensitivity of real-time PCR was greater in bleeding patients, especially in the gastric corpus: 68.4% (95% confidence interval [CI], 52.3 to 84.5%) in non-UGB patients versus 91.5% (95% CI, 79.6 to 97.6%) in UGB patients. When a positive result was defined as a number of microorganisms/human cell above the optimal value that maximizes the Youden index (>3.56 microorganisms/human cell in the antrum and >2.69 in the corpus), the sensitivity and specificity in UGB patients were over 80% in both antrum and corpus. Our findings suggest that some bleeding patients with infection caused by H. pylori may not be correctly diagnosed by classical methods, and such patients could benefit from the improved diagnosis provided by real-time PCR. However, the clinical significance of a small number of microorganisms in patients with negative results in classical tests should be evaluated.

Diagnosis and treatment of latent tuberculosis infection (LTBI) is the most effective strategy to control tuberculosis (TB) among patients with HIV infection. The tuberculin skin test (TST) was the only available method to identify LTBI. The aim of the present work was to evaluate the usefulness of the interferon-gamma release assays (IGRAs): QuantiFERON-tuberculosis (TB) Gold-In-Tube test (QFG) and T-SPOT.TB for the diagnosis of LTBI in a diverse cohort of HIV-infected patients.

Published Ahead of Print 25 July 2012. 10.1128/JCM.01205-12. 2012, 50(10):3233. DOI: J. Clin. Microbiol. Girona, Carlos Sillero and Gloria Royo Ruiz-García, Alicia Brotons, Elena López-Girona, Eva Rodríguez, Javier Sola-Vera, Antonio Galiana, Montserrat Jesús Saez, Sofía Belda, Miguel Santibáñez, Juan Carlos Other Classical Diagnostic Methods Gastrointestinal Bleeding: Comparison with pylori Infection in Patients with Upper Real-Time PCR for Diagnosing Helicobacter

The aim of this study was to determine the main diagnostic validity parameters of a quantitative real-time polymerase chain reaction (PCR) system for detecting Helicobacter pylori in gastric biopsies. Prospective study. The real-time PCR has an internal control for eliminating the false negatives. Our system has a good diagnostic capacity compared with the gold standard and was superior in antral mucosa: area under the curve was 0.91 for antrum (95% confidence interval [CI] 0.87 to 0.96) and 0.83 for corpus (95% CI 0.77 to 0.9). The optimum cut-off point was 3.56 microorganisms/cell for antrum (sensitivity 83.5% [95% CI 74.2 to 89.9]; specificity 91.3% [95% CI 82.3 to 96.0]; positive predictive value 92.2%; negative predictive value 81.8%). The positive likelihood ratios were 9.61 and 8.52 for antrum and corpus, respectively. With the cut-off point that maximises the Youden index, 8.7% false positives were obtained. Our methodology is useful for diagnosing infection due to H. pylori and the false positives detected probably correspond to patients who were actually infected but the infection was not detected by traditional techniques. The clinical importance of these cases should be studied in greater detail since they may involve colonisations unrelated to the patient's digestive pathology.

A monovalent rotavirus vaccine (RV1) was introduced into the National Immunization Program in Kenya in July 2014. We examined the impact of the vaccine on hospitalization for all-cause acute gastroenteritis (AGE) and rotavirus-specific AGE and strain distribution at a large referral hospital which serves a predominantly peri-urban population in Central Kenya. Data on rotavirus AGE and strain distribution were derived from ongoing hospital-based AGE surveillance. Hospital administrative data were used to compare trends in all-cause AGE. Pre-vaccine (July 2009–June 2014) and post-vaccine (July 2014–June 2016) periods were compared for changes in hospitalization for all-cause AGE and rotavirus AGE and strain distribution. Following the vaccine introduction, the proportion of children aged <5 years hospitalized for rotavirus declined by 30% (95% CI: 19–45%) in the first year and 64% (95% CI: 49–77%) in the second year. Reductions in rotavirus positivity were most pronounced among the vaccine-eligible group (<12 months) in the first year post-vaccination at 42% (95% CI: 28–56%). Greater reductions of 67% (95% CI: 51–79%) were seen in the second year in the 12–23 months age group. Similarly, hospitalizations for all-cause AGE among children <5 years of age decreased by 31% (95% CI: 24–40%) in the first year and 58% (95% CI: 49–67%) in the second year of vaccine introduction. Seasonal peaks of rotavirus and all-cause AGE were reduced substantially. There was an increased detection of G2P[4], G3P[6] and G3P[8], which coincided temporally with the timing of the vaccine introduction. Thus, introducing the rotavirus vaccine into the routine immunization program in Kenya has resulted in a notable decline in rotavirus and all-cause AGE hospitalizations in Central Kenya. This provides early evidence for public health policy makers in Kenya to support the sustained use of the rotavirus vaccine in routine immunizations.

Sir, In the last decade, Actinobaculum schaalii, a Gram-positive, facultative anaerobic, coccoid rod, 1 has emerged as a uropathogen, mainly in elderly patients with underlying urological predispositions. 2 -4 Due to difficulties in cultivating A. schaalii, the incidence of the bacteria has probably been underestimated for many years.Unless microscopy of Gram's stains or wet smear is used for screeing urinary samples, specimens will often not be cultured in an atmosphere supporting growth of A. schaalii.However, even when cultured in a CO 2 -enriched atmosphere A. schaalii can often only be identified by PCR, as a study has shown that in 90% of the cases it occurs together with fast-growing commonly known uropathogens, and thus is overlooked. 3. schaalii is susceptible in vivo to nearly all b-lactams, such as amoxicillin or cephalosporins, but is resistant to trimethoprim and ciprofloxacin. 4In a recent study of A. schaalii performed by Cattoir et al., 5 the MICs of 12 different antimicrobial agents, including those commonly used for the treatment of urinary tract infections (UTIs), were determined.Pivmecillinam was not included, but it is often the antibiotic of choice for the oral treatment of UTIs in Scandinavia, e.g. in Denmark it accounts for approximately half of the defined daily doses used for UTIs. 6,7e therefore selected 18 clinical A. schaalii isolates and measured the MICs of mecillinam.Fourteen of the isolates were obtained from urine specimens and four were from blood cultures.As a confirmatory test, all isolates were screened using a real-time PCR assay specific for A. schaalii, 3 and the A. schaalii strain CCUG 27420 was used as a reference.The susceptibility testing was performed on Schaedler agar (Oxoid) supplemented with 5 mg/mL haemin, 1 mg/mL vitamin K1 and 5% sheep blood.An inoculum suspension adjusted to a turbidity equivalent to that of a 1 McFarland standard in 0.9% NaCl was spread on to the agar and incubated under anaerobic conditions at 358C for 48 h.The MIC of mecillinam was determined for all isolates using Etest (AB bioMe ´rieux, Solna, Sweden).Bacteroides fragilis ATCC 25285 was used as a quality control strain.The susceptibility testing of mecillinam against the 18 A. schaalii isolates showed MIC values in the range 0.5-2.0mg/L (Table 1), and the MIC 50 and MIC 90 were 1.0 and 2.0 mg/L, respectively.This is consistent with previous findings in which nine strains of A. schaalii were susceptible to mecillinam (amdinocillin), with an MIC range of 0.25-1.5 mg/L, an MIC 50 of 0.5 mg/L and an MIC 90 of 1.0 mg/L. 2 The present study suggests that pivmecillinam will be effective as an alternative to other b-lactams in the treatment of A. schaalii UTIs, although this b-lactam is not usually used against Gram-positive bacteria. 6The advantages of choosing pivmecillinam include the low level of resistance in urinary pathogens, in addition to the possibility of achieving very high urinary concentrations (.200 mg/L) due to active excretion into the urine. 6 conclusion, pivmecillinam as a first-choice antibiotic against UTIs probably covers A. schaalii, both when A. schaalii is identified in monocultures and more frequently when it occurs as a co-pathogen with common fast-growing uropathogens.