Josefa Pérez

Epidemiology and risk factors for infections due to AmpC β-lactamase-producing Escherichia coli

OBJECTIVES To describe the prevalence and risk factors for infection due to AmpC β-lactamase-producing Escherichia coli (AmpC-EC). METHODS For the prevalence study, all clinical isolates of E. coli with reduced susceptibility to third-generation cephalosporins were prospectively included from June 2010 to November 2011. For risk factor analysis, a case-control study was conducted. Cases were patients with an infection due to AmpC-EC. Controls were patients infected with cephalosporin-susceptible E. coli, matched 1 : 2. Detection of blaAmpC genes was done with a multiplex AmpC-PCR, and hyperproduction of E. coli chromosomal blaAmpC by quantitative RT-PCR. Alteration of the blaAmpC promoter was studied by PCR and sequencing. RESULTS We identified 243 (1.1%) AmpC-EC strains out of 21 563 clinical isolates. Three cases with strains carrying ESBLs, 18 strains that were considered due to colonization and 8 cases lost to clinical follow-up were excluded. Finally, 214 cases were included in the analysis. Ninety-one cases (42.5%) and 269 (62.8%) controls were strictly community acquired (P < 0.001). Thirty-five (16.3%) cases and 186 controls (43.5%) did not have any identifiable risk factor (P < 0.001). Among cases, 158 (73.8%) were found to harbour an acquired AmpC (73.4% CMY-2). Previous use of fluoroquinolones [OR 2.6 (95% CI 1.12-3.36); P = 0.008] was independently associated with AmpC-EC in the multivariate analysis. CONCLUSIONS Prevalence of AmpC in E. coli remains low in our area. Plasmid acquisition (CMY type) represents the main mechanism of AmpC production. A high proportion of community-acquired isolates and patients with no identifiable risk factors were found. Previous use of fluoroquinolones was identified as a risk factor.

Bacillus species pseudo-outbreak: construction works and collateral damage

We describe the investigation and management of a pseudo-outbreak of Bacillus spp. bacteraemia associated with construction work in an emergency department (ED). During the pseudo-outbreak period 59 out of 3469 (1.7%) blood cultures yielded Bacillus spp. versus 24 out of 7628 (0.31%) in 2012. Material, surfaces, and air samples showed environmental contamination. Cases rapidly declined following the implementation of infection control measures and the end of construction. Construction works at the ED caused environmental contamination that most probably led to the pseudo-outbreak of Bacillus bacteraemia. In hospital settings, the lack of correctly implemented effective barriers during construction may place patients and healthcare providers at risk as well as lead to pseudo-outbreaks.

Emerging extended-spectrum β-lactamase-producing Klebsiella pneumoniae causing community-onset urinary tract infections: a case–control–control study

The aim of this study was to determine the epidemiology and risk factors associated with community-onset urinary tract infections (CO-UTIs) due to extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-Kp). A cohort study including all consecutive patients with K. pneumoniae CO-UTI identified from January 2010 to December 2014 was conducted. Patients with CO-UTI due to ESBL-Kp were then included as cases in a retrospective case-control-control study; controls were outpatients with CO-UTI caused by non-ESBL-producing Escherichia coli and K. pneumoniae (non-ESBL-Ec and non-ESBL-Kp, respectively). Each control was matched in a 2:1 ratio according to patient age, sex and year of isolation. Genotyping confirming ESBL was performed by multiplex PCR and sequencing. The prevalence of ESBL-Kp CO-UTIs, calculated among all K. pneumoniae CO-UTIs, increased from 2.4% in 2010 to 10.3% in 2014 (P = 0.01). Among cases, 63.8% were truly community-acquired, and CTX-M-15 was the predominant β-lactamase enzyme type (79.3%). A total of 83 cases and 319 controls were studied. Being a nursing home resident [odds ratio (OR) = 8.8, 95% confidence interval (CI) 2.6-29.4] and previous cephalosporin use (OR = 4.01, 95% CI 1.8-9.2) were risk factors independently associated with CO-UTI due to ESBL-Kp. In conclusion, the prevalence of CO-UTIs due to ESBL-Kp is increasing. In most cases, ESBL-Kp CO-UTIs are community-acquired and produce CTX-M-15 β-lactamase. Exposure to cephalosporins and being a nursing home resident were risk factors associated with ESBL-Kp CO-UTIs. CTX-M-15-producing K. pneumoniae isolates are emerging in the community.

Serotype, virulence profile, antimicrobial resistance and macrolide-resistance determinants in Streptococcus agalactiae isolates in pregnant women and neonates in Catalonia, Spain

INTRODUCTION Streptococcus agalactiae, or group B streptococci (GBS), is the main aetiological agent of early neonatal sepsis in developed countries. This microorganism belongs to the gastrointestinal tract microbiota wherefrom it can colonize the vagina and be vertically transmitted to the child either before or at birth, and subsequently cause infection in the newborn. Approximately, 50% of newborns born to women with GBS become colonized, with 1-2% developing early neonatal infection if no preventive intervention is performed. The aim of this study was to characterize and compare serotypes, virulence factors and antimicrobial resistance of GBS isolates collected from pregnant women and newborns in several hospitals in Catalonia. METHODS 242 GBS strains were analyzed including 95 colonizers and 68 pathogenic strains isolated from pregnant women, and 79 strains isolated from neonates with sepsis in order to determine serotype, virulence and antimicrobial resistance. RESULTS Serotype distribution was different among the three groups, with serotypes Ia and II being significantly more frequent among colonizing strains (p=0.001 and 0.012, respectively). Virulence factors bca and scpB were significantly more frequent among neonatal strains than pathogenic or colonizing strains (p=0.0001 and 0.002, respectively). Pathogenic strains were significantly more resistant to erythromycin, clindamycin and azithromycin than their non-pathogenic counterparts. CONCLUSIONS Taking into account that neonatal sepsis represents a significant problem on a global scale, epidemiological surveillance, antimicrobial resistance and GBS virulence at the local level could provide important knowledge about these microorganisms as well as help to improve treatment and prevent invasive infection caused by this microorganism.

Prospective Cohort Study of Single-Day Doxycycline Therapy for Mediterranean Spotted Fever

Original Article 1 Length of the paper: 2032 words 2 Length of the abstract: 250 words 3 4 5 Title: Single-day doxycycline therapy for Mediterranean spotted fever: a prospective 6 cohort study 7 Running title: One-day doxycycline therapy for Mediterranean spotted fever 8 9 Authors: Elena Espejo, Marta Andrés, Maria-Consol Garcia, Anna Fajardo, Josefa 10 Pérez, Feliu Bella. 11 1 Infectious Diseases Unit, Internal Medicine Service, Hospital de Terrassa (Consorci 12 Sanitari de Terrassa), Ctra. Torrebonica s/n, 08227 Terrassa, Spain. 13 2 Internal Medicine Service, Hospital de Terrassa (Consorci Sanitari de Terrassa), Ctra. 14 Torrebonica s/n, 08227 Terrassa, Spain. 15 3 Microbiology Laboratory, Catlab, Vial Sant Jordi s/n, Pol. Ind. Can Mitjans, 08232 16 Viladecavalls, Spain. 17 18 19 20 Corresponding author: 21 Elena Espejo 22 Infectious Diseases Unit. Hospital de Terrassa (Consorci Sanitari de Terrassa). 23 Ctra. Torrebonica s/n. 08227 Terrassa, Spain 24 e-mail: 12088eea@comb.cat 25 Telephone: 34-937839488 26 Fax: 34-937003614 27 28 AAC Accepted Manuscript Posted Online 27 August 2018 Antimicrob. Agents Chemother. doi:10.1128/AAC.00978-18 Copyright