Niveles de anticuerpos bactericidas frente a meningococo C tras la vacunación de niños de 2 a 6 años de edad en Andalucía.

BACKGROUND In 1997, 18.5% of the cases of Meningococcal Disease caused b serogroup C in Andalusia were children between 2 and 4 years of age; ages where the initial immune response and the duration of the capsular A + C meningococcal polysaccharide vaccine is less than in older age groups. Research was designed in order to measure the immune response produced by this vaccine in children from 2 to 6 years of age and to compare it with the natural immunity present in unvaccinated children. METHODS I. Dual monitoring study: a) groups of children vaccinated previously and control groups, b) groups of children who were going to be vaccinated, for pre and post-vaccination (1, 6 and 12 months) analysis and a control group. II. The bactericidal activity was measured according to the standardised protocol of the CDC with regard to the strain of N. meningitidis C-11. The sera with bactericidal activity (TAB) > 1:8 were considered to be protective. RESULTS 1 and 2 months following vaccination, the proportion of TAB > 1:8 was significantly higher than that of the control group (65.6% and 73% in comparison to 2.2% and 12%). In the pre-vaccine and post-vaccine (after 6, 7, 12 and 13 months) verification, no significant difference between vaccinated individuals and controls was observed. CONCLUSIONS The differences between vaccinated and unvaccinated individuals 1 and 2 months following vaccination indicate seroconversion in the vaccinated individuals. For the age group of between 2 to 6 years of age, the bactericidal activity acquired decline quickly, as, after 6 months, differences between this group and the control group are no longer observed.

Impact of inadequate empirical therapy on the mortality of patients with bloodstream infections: a propensity score-based analysis.

The impact of the adequacy of empirical therapy on outcome for patients with bloodstream infections (BSI) is key for determining whether adequate empirical coverage should be prioritized over other, more conservative approaches. Recent systematic reviews outlined the need for new studies in the field, using improved methodologies. We assessed the impact of inadequate empirical treatment on the mortality of patients with BSI in the present-day context, incorporating recent methodological recommendations. A prospective multicenter cohort including all BSI episodes in adult patients was performed in 15 hospitals in Andalucía, Spain, over a 2-month period in 2006 to 2007. The main outcome variables were 14- and 30-day mortality. Adjusted analyses were performed by multivariate analysis and propensity score-based matching. Eight hundred one episodes were included. Inadequate empirical therapy was administered in 199 (24.8%) episodes; mortality at days 14 and 30 was 18.55% and 22.6%, respectively. After controlling for age, Charlson index, Pitt score, neutropenia, source, etiology, and presentation with severe sepsis or shock, inadequate empirical treatment was associated with increased mortality at days 14 and 30 (odds ratios [ORs], 2.12 and 1.56; 95% confidence intervals [95% CI], 1.34 to 3.34 and 1.01 to 2.40, respectively). The adjusted ORs after a propensity score-based matched analysis were 3.03 and 1.70 (95% CI, 1.60 to 5.74 and 0.98 to 2.98, respectively). In conclusion, inadequate empirical therapy is independently associated with increased mortality in patients with BSI. Programs to improve the quality of empirical therapy in patients with suspicion of BSI and optimization of definitive therapy should be implemented.

Clinical and epidemiological features and prognosis of complicated pyelonephritis: a prospective observational single hospital-based study.

BACKGROUND Complicated pyelonephritis (cPN), a common cause of hospital admission, is still a poorly-understood entity given the difficulty involved in its correct definition. The aim of this study was to analyze the main epidemiological, clinical, and microbiological characteristics of cPN and its prognosis in a large cohort of patients with cPN. METHODS We conducted a prospective, observational study including 1325 consecutive patients older than 14 years diagnosed with cPN and admitted to a tertiary university hospital between 1997-2013. After analyzing the main demographic, clinical and microbiological data, covariates found to be associated with attributable mortality in univariate analysis were included in a multivariate logistic regression model. RESULTS Of the 1325 patients, 689 (52%) were men and 636 (48%) women; median age 63 years, interquartile range [IQR] (46.5-73). Nine hundred and forty patients (70.9%) had functional or structural abnormalities in the urinary tract, 215 (16.2%) were immunocompromised, 152 (11.5%) had undergone a previous urinary tract instrumentation, and 196 (14.8%) had a long-term bladder catheter, nephrostomy tube or ureteral catheter. Urine culture was positive in 813 (67.7%) of the 1251 patients in whom it was done, and in the 1032 patients who had a blood culture, 366 (34%) had bacteraemia. Escherichia coli was the causative agent in 615 episodes (67%), Klebsiella spp in 73 (7.9%) and Proteus ssp in 61 (6.6%). Fourteen point one percent of GNB isolates were ESBL producers. In total, 343 patients (25.9%) developed severe sepsis and 165 (12.5%) septic shock. Crude mortality was 6.5% and attributable mortality was 4.1%. Multivariate analysis showed that an age >75 years (OR 2.77; 95% CI, 1.35-5.68), immunosuppression (OR 3.14; 95% CI, 1.47-6.70), and septic shock (OR 58.49; 95% CI, 26.6-128.5) were independently associated with attributable mortality. CONCLUSIONS cPN generates a high morbidity and mortality and likely a great consumption of healthcare resources. This study highlights the factors directly associated with mortality, though further studies are needed in the near future aimed at identifying subgroups of low-risk patients susceptible to outpatient management.

Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features.

Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use.

Four main virotypes among extended-spectrum-β-lactamase-producing isolates of Escherichia coli O25b:H4-B2-ST131: bacterial, epidemiological, and clinical characteristics.

A total of 1,021 extended-spectrum-β-lactamase-producing Escherichia coli (ESBLEC) isolates obtained in 2006 during a Spanish national survey conducted in 44 hospitals were analyzed for the presence of the O25b:H4-B2-ST131 (sequence type 131) clonal group. Overall, 195 (19%) O25b-ST131 isolates were detected, with prevalence rates ranging from 0% to 52% per hospital. Molecular characterization of 130 representative O25b-ST131 isolates showed that 96 (74%) were positive for CTX-M-15, 15 (12%) for CTX-M-14, 9 (7%) for SHV-12, 6 (5%) for CTX-M-9, 5 (4%) for CTX-M-32, and 1 (0.7%) each for CTX-M-3 and the new ESBL enzyme CTX-M-103. The 130 O25b-ST131 isolates exhibited relatively high virulence scores (mean, 14.4 virulence genes). Although the virulence profiles of the O25b-ST131 isolates were fairly homogeneous, they could be classified into four main virotypes based on the presence or absence of four distinctive virulence genes: virotypes A (22%) (afa FM955459 positive, iroN negative, ibeA negative, sat positive or negative), B (31%) (afa FM955459 negative, iroN positive, ibeA negative, sat positive or negative), C (32%) (afa FM955459 negative, iroN negative, ibeA negative, sat positive), and D (13%) (afa FM955459 negative, iroN positive or negative, ibeA positive, sat positive or negative). The four virotypes were also identified in other countries, with virotype C being overrepresented internationally. Correspondingly, an analysis of XbaI macrorestriction profiles revealed four major clusters, which were largely virotype specific. Certain epidemiological and clinical features corresponded with the virotype. Statistically significant virotype-specific associations included, for virotype B, older age and a lower frequency of infection (versus colonization), for virotype C, a higher frequency of infection, and for virotype D, younger age and community-acquired infections. In isolates of the O25b:H4-B2-ST131 clonal group, these findings uniquely define four main virotypes, which are internationally distributed, correspond with pulsed-field gel electrophoresis (PFGE) profiles, and exhibit distinctive clinical-epidemiological associations.

Rapid diagnosis of human brucellosis by peripheral-blood PCR assay.

A single-step PCR assay with genus-specific primers for the amplification of a 223-bp region of the sequence encoding a 31-kDa immunogenetic Brucella abortus protein (BCSP31) was used for the rapid diagnosis of human brucellosis. We examined peripheral blood from 47 patients, with a total of 50 cases of brucellosis, and a group of 60 control subjects, composed of patients with febrile syndromes of several etiologies other than brucellosis, asymptomatic subjects seropositive for Brucella antibodies, and healthy subjects. Diagnosis of brucellosis was established in 35 cases (70%) by isolation of Brucella in blood culture and in the other 15 cases (30%) by clinical and serological means. The sensitivity of our PCR assay was 100%, since it correctly identified all 50 cases of brucellosis, regardless of the duration of the disease, the positivity of the blood culture, or the presence of focal forms. The specificity of the test was 98.3%, and the only false-positive result was for a patient who had had brucellosis 2 months before and possibly had a self-limited relapse. In those patients who relapsed, the results of our PCR assay were positive for both the initial infection and the relapse, becoming negative once the relapse treatment was completed and remaining negative in the follow-up tests at 2, 4, and 6 months. In conclusion, these results suggest that the PCR assay is rapid and easy to perform and highly sensitive and specific, and it may therefore be considered a useful tool for diagnosis of human brucellosis.

Diagnostic yield of a PCR assay in focal complications of brucellosis.

In order to evaluate the diagnostic yield of a PCR assay for patients with focal complications of brucellosis, we studied by PCR and by conventional microbiological techniques 34 nonblood samples from 32 patients with different focal forms of brucellosis. The samples from patients with brucellosis were paired to an equal number of control samples from the same locations of patients whose illnesses had different etiologies. Thirty-three of the 34 nonblood samples (97%) from the brucellosis patients were positive by PCR, whereas Brucella spp. were isolated from only 29.4% of the conventional cultures. For 11.4% of the patients, the confirmatory serological tests were either negative or showed titers below the diagnostic range. Two patients (6.2%) from the control group, both with tuberculous vertebral osteomyelitis, had a positive PCR result. The brucella PCR of blood from these two patients was also positive, and the two strains of Mycobacterium tuberculosis isolated were analyzed by the brucella PCR, with no evidence of amplification. These results show that the PCR assay is far more sensitive than conventional cultures, and this, coupled with its speed and reduction in risk to laboratory workers, makes this technique a very useful tool for the diagnosis of focal complications of brucellosis.

Strategy for optimizing DNA amplification in a peripheral blood PCR assay used for diagnosis of human brucellosis.

We studied two of the possible factors which can interfere with specific DNA amplification in a peripheral-blood PCR assay used for the diagnosis of human brucellosis. We found that high concentrations of leukocyte DNA and heme compounds inhibit PCR. These inhibitors can be efficiently suppressed by increasing the number of washings to four or five and decreasing the amount of total DNA to 2 to 4 microg, thereby avoiding false-negative results.

Acquisition and cross-transmission of Staphylococcus aureus in European intensive care units

Objective. To study the acquisition and cross-transmission of Staphylococcus aureus in different intensive care units (ICUs). Methods. We performed a multicenter cohort study. Six ICUs in 6 countries participated. During a 3-month period at each ICU, all patients had nasal and perineal swab specimens obtained at ICU admission and during their stay. All S. aureus isolates that were collected were genotyped by spa typing and multilocus variable-number tandem-repeat analysis typing for cross-transmission analysis. A total of 629 patients were admitted to ICUs, and 224 of these patients were found to be colonized with S. aureus at least once during ICU stay (22% were found to be colonized with methicillin-resistant S. aureus [MRSA]). A total of 316 patients who had test results negative for S. aureus at ICU admission and had at least 1 follow-up swab sample obtained for culture were eligible for acquisition analysis. Results. A total of 45 patients acquired S. aureus during ICU stay (31 acquired methicillin-susceptible S. aureus [MSSA], and 14 acquired MRSA). Several factors that were believed to affect the rate of acquisition of S. aureus were analyzed in univariate and multivariate analyses, including the amount of hand disinfectant used, colonization pressure, number of beds per nurse, antibiotic use, length of stay, and ICU setting (private room versus open ICU treatment). Greater colonization pressure and a greater number of beds per nurse correlated with a higher rate of acquisition for both MSSA and MRSA. The type of ICU setting was related to MRSA acquisition only, and the amount of hand disinfectant used was related to MSSA acquisition only. In 18 (40%) of the cases of S. aureus acquisition, cross-transmission from another patient was possible. Conclusions. Colonization pressure, the number of beds per nurse, and the treatment of all patients in private rooms correlated with the number of S. aureus acquisitions on an ICU. The amount of hand disinfectant used was correlated with the number of cases of MSSA acquisition but not with the number of cases of MRSA acquisition. The number of cases of patient-to-patient cross-transmission was comparable for MSSA and MRSA.

Colonization with multiple Staphylococcus aureus strains among patients in European intensive care units.

Patients and healthy individuals intermittently and inconsistently carry different methicillin-resistant Staphylococcus aureus (MRSA) subtypes. In the present study, we assessed the clonality of methicillin-susceptible S. aureus (MSSA) and MRSA strains in patients admitted to 1 of 6 intensive care units (ICUs), using spa typing and multilocus variable number of tandem repeats analysis (MLVA).

Comportamiento del orificio de implantación del catéter en pacientes en diálisis peritoneal en relación a los cuidados

Infections of the catheter wound in peritoneal dialysis are the most frequent cause of morbility in patients who undergo this technique. There are a number of procedures for the care of the wound and it is not easy to define a single method that will guarantee good condition of the wound. In order to evaluate the behaviour of the wound related to the procedure used in their care, we studied 306 patients over 24 months, compiling socio-demographic and clinical variables. We found a high incidence of infections caused by gram-positive skin and mucous germs, with a strong correlation with the fact that the patient/family carer is a nasal carrier of staphylococcus aureus and that they appear more frequently in patients who do not remove the wound dressing in the shower. We also detected an increase in pseudomonas infections when the patient does not dry the wound with a hair-dryer

Pediatric parapneumonic empyema, Spain

Pediatric parapneumonic empyema (PPE) has been increasing in several countries including Spain. Streptococcus pneumoniae is a major PPE pathogen; however, antimicrobial pretreatment before pleural fluid (PF) sampling frequently results in negative diagnostic cultures, thus greatly underestimating the contribution of pneumococci, especially pneumococci susceptible to antimicrobial agents, to PPE. The study aim was to identify the serotypes and genotypes that cause PPE by using molecular diagnostics and relate these data to disease incidence and severity. A total of 208 children with PPE were prospectively enrolled; blood and PF samples were collected. Pneumococci were detected in 79% of culture-positive and 84% of culture-negative samples. All pneumococci were genotyped by multilocus sequence typing. Serotypes were determined for 111 PPE cases; 48% were serotype 1, of 3 major genotypes previously circulating in Spain. Variance in patient complication rates was statistically significant by serotype. The recent PPE increase is principally due to nonvaccine serotypes, especially the highly invasive serotype 1.

Streptococcus pneumoniae bacteremia: clinical and microbiological epidemiology in a health area of Southern Spain

Streptococcus pneumoniae remains an important cause of bacteremia worldwide. Last years, a decrease of S. pneumoniae penicillin-resistant isolates has been observed. The objective of this study was to describe the episodes of bacteremia due to S. pneumoniae during a period of 11 years. Epidemiological and clinical data, serotypes causing bacteremia, antibiotic susceptibility and prognosis factors were studied. Over a period of 11 years, all the episodes of S. pneumoniae bacteremia were analysed. Their clinical and microbiological features were recorded. Statistical analysis was carried out to determine risk factors for pneumococcal bacteremia and predictors of fatal outcome. Finally, 67 S. pneumoniae bacteremia episodes were included in this study. The majority of cases were produced in white men in the middle age of their life. The main predisposing factors observed were smoking, antimicrobial and/or corticosteroids administration, chronic pulmonary obstructive disease and HIV infection, and the most common source of bacteremia was the low respiratory tract. The main serotypes found were 19A, 1, 14 and 7F. Seventy-seven percent of these isolates were penicillin-susceptible, and the mortality in this serie was really low. Statistical significance was observed between age, sex and race factors and the presence of bacteremia, and there was relationship between the patient’s condition and the outcome. In our study, S. pneumoniae bacteremia is mainly from community-acquired origin mainly caused in men in the median age of the life. 40% of bacteremias were caused by serotypes 19A, 1, 7F and 14. During the period of study the incidence of bacteremia was stable and the mortality rate was very low.

Gut Microbiota Composition in Male Rat Models under Different Nutritional Status and Physical Activity and Its Association with Serum Leptin and Ghrelin Levels.

BACKGROUND Several evidences indicate that gut microbiota is involved in the control of host energy metabolism. OBJECTIVE To evaluate the differences in the composition of gut microbiota in rat models under different nutritional status and physical activity and to identify their associations with serum leptin and ghrelin levels. METHODS IN A CASE CONTROL STUDY, FORTY MALE RATS WERE RANDOMLY ASSIGNED TO ONE OF THESE FOUR EXPERIMENTAL GROUPS: ABA group with food restriction and free access to exercise; control ABA group with food restriction and no access to exercise; exercise group with free access to exercise and feed ad libitum and ad libitum group without access to exercise and feed ad libitum. The fecal bacteria composition was investigated by PCR-denaturing gradient gel electrophoresis and real-time qPCR. RESULTS In restricted eaters, we have found a significant increase in the number of Proteobacteria, Bacteroides, Clostridium, Enterococcus, Prevotella and M. smithii and a significant decrease in the quantities of Actinobacteria, Firmicutes, Bacteroidetes, B. coccoides-E. rectale group, Lactobacillus and Bifidobacterium with respect to unrestricted eaters. Moreover, a significant increase in the number of Lactobacillus, Bifidobacterium and B. coccoides-E. rectale group was observed in exercise group with respect to the rest of groups. We also found a significant positive correlation between the quantity of Bifidobacterium and Lactobacillus and serum leptin levels, and a significant and negative correlation among the number of Clostridium, Bacteroides and Prevotella and serum leptin levels in all experimental groups. Furthermore, serum ghrelin levels were negatively correlated with the quantity of Bifidobacterium, Lactobacillus and B. coccoides-Eubacterium rectale group and positively correlated with the number of Bacteroides and Prevotella. CONCLUSIONS Nutritional status and physical activity alter gut microbiota composition affecting the diversity and similarity. This study highlights the associations between gut microbiota and appetite-regulating hormones that may be important in terms of satiety and host metabolism.

Comparative clinical study of different multiplex real time PCR strategies for the simultaneous differential diagnosis between extrapulmonary tuberculosis and focal complications of brucellosis

Background: Both brucellosis and tuberculosis are chronic-debilitating systemic granulomatous diseases with a high incidence in many countries in Africa, Central and South America, the Middle East and the Indian subcontinent. Certain focal complications of brucellosis and extrapulmonary tuberculosis are very difficult to differentiate clinically, biologically and radiologically. As the conventional microbiological methods for the diagnosis of the two diseases have many limitations, as well as being time-consuming, multiplex real time PCR (M RT-PCR) could be a promising and practical approach to hasten the differential diagnosis and improve prognosis. Methodology/Principal Findings: We designed a SYBR Green single-tube multiplex real-time PCR protocol targeting bcsp31 and the IS711 sequence detecting all pathogenic species and biovars of Brucella genus, the IS6110 sequence detecting Mycobacterium genus, and the intergenic region senX3-regX3 specifically detecting Mycobacterium tuberculosis complex. The diagnostic yield of the M RT-PCR with the three pairs of resultant amplicons was then analyzed in 91 clinical samples corresponding to 30 patients with focal complications of brucellosis, 24 patients with extrapulmonary tuberculosis, and 36 patients (Control Group) with different infectious, autoimmune or neoplastic diseases. Thirty-five patients had vertebral osteomyelitis, 21 subacute or chronic meningitis or meningoencephalitis, 13 liver or splenic abscess, eight orchiepididymitis, seven subacute or chronic arthritis, and the remaining seven samples were from different locations. Of the three pairs of amplicons (senX3-regX3+ bcsp3, senX3-regX3+ IS711 and IS6110+ IS711) only senX3-regX3+ IS711 was 100% specific for both the Brucella genus and M. tuberculosis complex. For all the clinical samples studied, the overall sensitivity, specificity, and positive and negative predictive values of the M RT-PCR assay were 89.1%, 100%, 85.7% and 100%, respectively, with an accuracy of 93.4%, (95% CI, 88.3—96.5%). Conclusions/Significance: In this study, a M RT-PCR strategy with species-specific primers based on senX3-regX3+IS711 sequences proved to be a sensitive and specific test, useful for the highly efficient detection of M. tuberculosis and Brucella spp in very different clinical samples. It thus represents an advance in the differential diagnosis between some forms of extrapulmonary tuberculosis and focal complications of brucellosis.