Rosa Bartolomé

Assessment of the Capacity of Lactobacillus to Inhibit the Growth of Uropathogens and Block Their Adhesion to Vaginal Epithelial Cells

To gain insight into the mechanisms by which Lactobacillus blocks the adherence of uropathogens to vaginal epithelial cells and inhibits their growth, 15 Lactobacillus strains and 22 uropathogens were studied. Lactobacilli from hemagglutination group III, identified as Lactobacillus crispatus, showed greater capacity to block uropathogen adherence than those from hemagglutination groups II and I (61.9%, 49.5%, and 52.6% of blockage, respectively). Pseudomonas aeruginosa PA5 and Klebsiella pneumoniae KP7 were the uropathogens most susceptible to blockage, and Staphylococcus aureus SA11 and Proteus mirabilis PM1 were the most resistant. Lactobacillus inhibited uropathogen growth better in liquid assays; the 3 Lactobacillus groups showed similar inhibitory power (72.3%, 71.9%, and 74.2% of light transmittance). P. aeruginosa PA5 was the most inhibited, and Enterococcus species E15 was the least inhibited. There is considerable variation among Lactobacillus strains regarding their adherence to uroepithelium, blockage of uropathogen attachment, and inhibition of uropathogen growth. Although these properties are independent, they may coincide and therefore allow for these strains to balance the vaginal ecosystem and to make them useful as probiotics.

Prospective Multicenter Study of Carbapenemase-Producing Enterobacteriaceae from 83 Hospitals in Spain Reveals High In Vitro Susceptibility to Colistin and Meropenem

ABSTRACT The aim of this study was to determine the impact of carbapenemase-producing Enterobacteriaceae (CPE) in Spain in 2013 by describing the prevalence, dissemination, and geographic distribution of CPE clones, and their population structure and antibiotic susceptibility. From February 2013 to May 2013, 83 hospitals (about 40,000 hospital beds) prospectively collected nonduplicate Enterobacteriaceae using the screening cutoff recommended by EUCAST. Carbapenemase characterization was performed by phenotypic methods and confirmed by PCR and sequencing. Multilocus sequencing types (MLST) were determined for Klebsiella pneumoniae and Escherichia coli. A total of 702 Enterobacteriaceae isolates met the inclusion criteria; 379 (54%) were CPE. OXA-48 (71.5%) and VIM-1 (25.3%) were the most frequent carbapenemases, and K. pneumoniae (74.4%), Enterobacter cloacae (10.3%), and E. coli (8.4%) were the species most affected. Susceptibility to colistin, amikacin, and meropenem was 95.5%, 81.3%, and 74.7%, respectively. The most prevalent sequence types (STs) were ST11 and ST405 for K. pneumoniae and ST131 for E. coli. Forty-five (54.1%) of the hospitals had at least one CPE case. For K. pneumoniae, ST11/OXA-48, ST15/OXA-48, ST405/OXA-48, and ST11/VIM-1 were detected in two or more Spanish provinces. ST11 isolates carried four carbapenemases (VIM-1, OXA-48, KPC-2, and OXA-245), but ST405 isolates carried OXA-48 only. A wide interregional spread of CPE in Spain was observed, mainly due to a few successful clones of OXA-48-producing K. pneumoniae (e.g., ST11 and ST405). The dissemination of OXA-48-producing E. coli is a new finding of public health concern. According to the susceptibilities determined in vitro, most of the CPE (94.5%) had three or more options for antibiotic treatment.

Silver Nitrate: Antimicrobial Activity Related to Cytotoxicity in Cultured Human Fibroblasts

The aims of this study were to ascertain whether silver nitrate (AgNO3) concentrations below those used in clinical practice inhibit bacterial growth, and in parallel study the cytotoxic effects on human fibroblasts. The cytoprotective effects of fetal calf serum (FCS) were also evaluated. The cytotoxic effects of eight different silver nitrate concentrations were determined by assessing mitochondrial activity of viable cells capable of cleaving tetrazolium salts. Antimicrobial activity of AgNO3, range: 7–550 × 10–5%, was tested against Staphylococcus aureus, Citrobacter freundii, and Pseudomonas aeruginosa. Silver nitrate concentrations exerting antimicrobial effects were: S. aureus, >70 × 10–5%; P. aeruginosa, ≥270 × 10–5%, and C. freundii, ≥550 × 10–5%. With 2% FCS, the lowest AgNO3 concentration studied (7 × 10–5%) showed cytotoxic effects (cell survival 71 ± 19%) at only 2 h of incubation. Under these conditions AgNO3 cytotoxicity was time- and concentration-dependent in all exposure periods. Cytotoxicity was greatly enhanced causing 76% fibroblast growth inhibition at concenctrations of 14 × 10–5% and contact time of 2 h. The AgNO3 concentration of 7 × 10–5% was also cytotoxic with 5% FCS in the media compared with controls, although cell survival was higher than with 2% FCS. The cytoprotective action of FCS was clearly shown at the concentration of 10% at which AgNO3 cytotoxicity of 7 × 10–5% to 28 × 10–5% was partially or completely inhibited. Our results show that AgNO3 at concentrations 100–700 times more diluted than that normally used in clinical practice retained effective inhibitory activity against some of the above-mentioned microorganisms. However, even these concentrations are cytotoxic for cultured fibroblasts. Thus, silver nitrate concentrations up to 100 times more diluted can be used, since they possess bacterial growth-inhibiting power, are less cytotoxic and therefore favour wound healing.

Epidemiology of Clostridium difficile infection and risk factors for unfavorable clinical outcomes: Results of a hospital-based study in Barcelona, Spain

ABSTRACT Prospective hospital-based surveillance for Clostridium difficile-associated disease (CDAD) was conducted in Barcelona (Spain) to describe the epidemiology of this condition and investigate the risk factors for an unfavorable outcome. All patients diagnosed with CDAD during 2009 were included. Using logistic regression modeling, we analyzed the potential risk factors associated with recurrent and complicated CDAD, defined as a need for colectomy or death within 30 days. There were 365 episodes of CDAD, yielding an incidence of 22.5 cases/105 person-years, 1.22 cases/103 hospital discharges, and 1.93 cases/104 patient-days. The main PCR ribotypes identified were 241 (26%), 126 (18%), 078 (7%), and 020 (5%). PCR ribotype 027 was not detected. Among the 348 cases analyzed, 232 (67%) patients were cured, 63 (18%) had a recurrence of CDAD, and 53 (15%) developed complicated CDAD. Predictors of complicated CDAD were continued use of antibiotics following CDAD diagnosis (odds ratio [OR], 2.009; 95% confidence interval [CI], 1.012 to 3.988; P = 0.046), Charlson comorbidity index score (OR, 1.265; 95% CI, 1.105 to 1.449; P = 0.001), and age (OR, 1.028; 95% CI, 1.005 to 1.053; P = 0.019). A leukocyte count of >15 × 103 cells/ml (OR, 2.277; 95% CI, 1.189 to 4.362; P = 0.013), continuation of proton pump inhibitor (PPI) use after CDAD diagnosis (OR, 2.168; 95% CI, 1.081 to 4.347; P = 0.029), and age (OR, 1.021; 95% CI, 1.001 to 1.041; P = 0.036) were independently associated with higher odds of recurrence. The incidence of CDAD in Barcelona during 2009 was on the lower end of the previously described range for all of Europe. Our analysis suggests that the continuation of non-C. difficile antibiotics and use of PPIs in patients diagnosed with CDAD are associated with unfavorable clinical outcomes.

Dissemination of extended-spectrum β-lactamase-producing bacteria: the food-borne outbreak lesson

OBJECTIVES Commensal and opportunistic bacteria producing extended-spectrum beta-lactamases (ESBL-PB) have undergone a broad and rapid spread within the general population; however, the routes of dissemination have not been totally elucidated. The aim of this study was to determine whether individuals involved in an outbreak of acute gastroenteritis, in addition to the enteropathogenic microorganism, share an ESBL-PB as indirect demonstration of its transmission from a common food source. METHODS From 2003 to 2004 in Barcelona, Spain, stool samples from 905 people involved in 132 acute gastroenteritis outbreaks and 226 food handlers related to the outbreaks were investigated. RESULTS In 31 outbreaks, 58 diners carrying one or more ESBL-PB were detected. In 10 outbreaks, two or more diners shared the same ESBL-PB, and in four of them, the strain was shared with the food handlers. CONCLUSIONS This study provides circumstantial evidence that foods can be a transmission vector for ESBL-PB, probably from two reservoirs, food animals and food handlers.

Serotypes and clones causing invasive pneumococcal disease before the use of new conjugate vaccines in Catalonia, Spain

OBJECTIVES The objective of this study was to learn the serotype distribution and clonal composition of pneumococci causing invasive pneumococcal disease (IPD) in children and adults in Spain before the introduction of new 10-valent (PCV10) and 13-valent (PCV13) conjugate vaccines. METHODS This is a 1-year prospective study including all patients with culture-proved IPD admitted to 30 medical centers in Catalonia, Spain, during the year 2009. RESULTS A total of 614 episodes of IPD occurred in 612 patients. The rates of IPD were highest in children aged <24 months and adults >64 years (64.5 and 44.7 per 100,000 population). The burden of disease was mainly due to pneumonia in all age ranges. 609 of 614 strains were serotyped and 47 different serotypes were found. Among the 609 IPD cases with known serotype, 12.2% were caused by PCV7 serotypes, 51% by PCV10 serotypes, and 71.7% by PCV13 serotypes. 608 of 614 isolates were characterized by MLST. The main clonal types detected were ST306, CC191 and CC230. CONCLUSIONS PCV13 conjugate vaccine offers good coverage against IPD in Catalonia, Spain. However, the high genetic diversity of pneumococci highlights the importance of molecular surveillance systems for monitoring IPD during the vaccination period. SUMMARY This study shows that 13-valent conjugate vaccine offers good coverage against invasive pneumococcal disease in children and adults in Spain. However, the high genetic diversity of pneumococci highlights the importance of molecular surveillance systems for monitoring IPD during the vaccination period.

Sequential Evolution of Genotype GII.4 Norovirus Variants Causing Gastroenteritis Outbreaks From 2001 to 2006 in Eastern Spain

Noroviruses are the most common cause of outbreaks of viral gastroenteritis worldwide. Norovirus outbreaks were surveyed in Catalonia and the region of Valencia (Eastern Spain) between January 2001 and December 2006 as part of the European Union funded network “Food‐borne viruses in Europe”. During this time the etiology and epidemiological features of 194 outbreaks of acute non‐bacterial gastroenteritis were investigated and norovirus was identified as causing 169 (87.1%) of them. Molecular epidemiology of viral strains was studied by RT‐PCR and sequencing part of the RNA polymerase gene in ORF1 from 153 outbreak strains. The most commonly identified norovirus genotype was GII.4 (71.9% of the characterized outbreak strains), which is also the predominant genotype worldwide. During this survey five genetic variants of GII.4 genotype have been sequentially detected and identified as 1996, 2002, 2004, 2006a, and 2006b variants. The transition from one variant to a new one always took place over a short period of time, and thereafter the replacement of strains circulating previously was observed. These new GII.4 variants may have arisen as a consequence of viral evasion from the host immune responses, although apparently there is a lack of long‐term immunity after norovirus infections. J. Med. Virol. 80: 1288–1295, 2008.

Papel de Lactobacillus como factor protector de la candidiasis vaginal

Fundamento Esclarecer el papel protector de Lactobacillus frente a la vulvovaginitis candidiasica. Pacientes y metodo Estudio in vitro que determina la capacidad de 15 cepas de Lactobacillus de bloquear la adhesion de dos cepas de Candida albicans y una de C. glabrata a las celulas epiteliales vaginales, asi como la capacidad de inhibir el crecimiento de estas levaduras. Ademas se ha determinado la presencia de Lactobacillus en 115 exudados vaginales de mujeres con vulvovaginitis candidiasica. Resultados Solo 8 de los 15 Lactobacillus bloquearon significativamente la adhesion de C. albicans Y18 a las celulas vaginales. Lactobacillus del grupo hemaglutinante III presentaron la mayor capacidad de bloqueo (62,9%), seguidos de los grupos II (50,6%) y I (26,1%). Ninguno de los 15 Lactobacillus estudiados fue capaz de inhibir en medio solido el crecimiento de las tres levaduras; sin embargo, en medio liquido algunos Lactobacillus evidenciaron cierto poder inhibidor frente a C. albicans Y17 (35,7, 41,7 y 38,1% de transmitancia para los Lactobacillus de los grupos I, II y III, respectivamente). Se detecto la presencia de Lactobacillus en el 89,6% de las mujeres con vulvovaginitis candidiasica, en el 87,8% mediante visualizacion microscopica y en el 72,2% mediante cultivo. Conclusion Los resultados de este estudio sugieren que probablemente Lactobacillus ejerce proteccion contra la vulvovaginitis candidiasica.

Spanish Multicenter Study of the Epidemiology and Mechanisms of Amoxicillin-Clavulanate Resistance in Escherichia coli

ABSTRACT We conducted a prospective multicenter study in Spain to characterize the mechanisms of resistance to amoxicillin-clavulanate (AMC) in Escherichia coli. Up to 44 AMC-resistant E. coli isolates (MIC ≥ 32/16 μg/ml) were collected at each of the seven participant hospitals. Resistance mechanisms were characterized by PCR and sequencing. Molecular epidemiology was studied by pulsed-field gel electrophoresis (PFGE) and by multilocus sequence typing. Overall AMC resistance was 9.3%. The resistance mechanisms detected in the 257 AMC-resistant isolates were OXA-1 production (26.1%), hyperproduction of penicillinase (22.6%), production of plasmidic AmpC (19.5%), hyperproduction of chromosomic AmpC (18.3%), and production of inhibitor-resistant TEM (IRT) (17.5%). The IRTs identified were TEM-40 (33.3%), TEM-30 (28.9%), TEM-33 (11.1%), TEM-32 (4.4%), TEM-34 (4.4%), TEM-35 (2.2%), TEM-54 (2.2%), TEM-76 (2.2%), TEM-79 (2.2%), and the new TEM-185 (8.8%). By PFGE, a high degree of genetic diversity was observed although two well-defined clusters were detected in the OXA-1-producing isolates: the C1 cluster consisting of 19 phylogroup A/sequence type 88 [ST88] isolates and the C2 cluster consisting of 19 phylogroup B2/ST131 isolates (16 of them producing CTX-M-15). Each of the clusters was detected in six different hospitals. In total, 21.8% of the isolates were serotype O25b/phylogroup B2 (O25b/B2). AMC resistance in E. coli is widespread in Spain at the hospital and community levels. A high prevalence of OXA-1 was found. Although resistant isolates were genetically diverse, clonality was linked to OXA-1-producing isolates of the STs 88 and 131. Dissemination of IRTs was frequent, and the epidemic O25b/B2/ST131 clone carried many different mechanisms of AMC resistance.

Epidemiological and clinical features of norovirus gastroenteritis in outbreaks: a population-based study

Noroviruses are the most frequent cause of acute gastroenteritis in the community. In Catalonia, it is not clear how this type of viral gastroenteritis is evolving, and the objective of this prospective population-based study was to describe the incidence and epidemiological and clinical features of outbreaks of acute gastroenteritis due to norovirus in Catalonia between October 2004 and October 2005. Incidence rates were calculated using the estimated population of Catalonia in 2005. For each outbreak, the mode of transmission, the number of persons affected, demographic variables, clinical presentation, the date and time of onset of symptoms and the duration of symptoms, physician visits and hospitalizations were collected. Sixty viral outbreaks affecting 1791 people were identified, with no distinct seasonality. The mean number of outbreaks per month was 4.6. The global incidence was 24.6 per 100 000 person-years. The incidence was higher in women (25.7 per 100 000 person-years) and in the 5-11 years (52.4 per 100 000 person-years) and > or =65 years (42.4 per 100 000 person-years) age groups. The prevalence of vomiting, abdominal pain and general malaise was higher in children and adolescents, whereas the prevalence of diarrhoea and myalgia was higher in adults. These results suggest that norovirus infection has an important public health impact in Catalonia and that prevention strategies should be designed and implemented.