Incorporation of Actinobacillus pleuropneumoniae in Preformed Biofilms by Escherichia coli Isolated From Drinking Water of Swine Farms.

Actinobacillus pleuropneumoniae, the etiological agent of porcine pleuropneumonia, represents one of the most important health problems in the swine industry worldwide and it is included in the porcine respiratory disease complex. One of the bacterial survival strategies is biofilm formation, which are bacterial communities embedded in an extracellular matrix that could be attached to a living or an inert surface. Until recently, A. pleuropneumoniae was considered to be an obligate pathogen. However, recent studies have shown that A. pleuropneumoniae is present in farm drinking water. In this study, the drinking water microbial communities of Aguascalientes (Mexico) swine farms were analyzed, where the most frequent isolated bacterium was Escherichia coli. Biofilm formation was tested in vitro; producing E. coli biofilms under optimal growth conditions; subsequently, A. pleuropneumoniae serotype 1 (strains 4074 and 719) was incorporated to these biofilms. Interaction between both bacteria was evidenced, producing an increase in biofilm formation. Extracellular matrix composition of two-species biofilms was also characterized using fluorescent markers and enzyme treatments. In conclusion, results confirm that A. pleuropneumoniae is capable of integrates into biofilms formed by environmental bacteria, indicative of a possible survival strategy in the environment and a mechanism for disease dispersion.

Impact of Multiplex Polymerase Chain Reaction Testing for Respiratory Pathogens on Healthcare Resource Utilization for Pediatric Inpatients.

OBJECTIVE: To assess whether multiplex polymerase chain reaction (mPCR) vs non-mPCR testing impacts the use of antibiotics, chest radiographs, and isolation precautions. STUDY DESIGN: We retrospectively compared use of antibiotics, chest radiographs, and isolation precautions for patients <18 years old (excluding neonates) hospitalized at a tertiary referral center tested for respiratory pathogens in the emergency department or during the first 2 hospital days, during 2 periods: June 2010-June 2012 (non-mPCR group) vs October 2012-May 2014 (mPCR group). RESULTS: Subjects (n = 2430) in the mPCR group were older, had more complex chronic conditions, and were admitted to the pediatric intensive care unit more often compared with the non-mPCR (n = 2349) group. Subjects in the mPCR group had more positive tests (42.4% vs 14.4%, P < .01), received fewer days of antibiotics (4 vs 5 median antibiotic days, P < .01), fewer chest radiographs performed, (59% vs 78%, P < .01), and were placed in isolation longer (20 vs 0 median isolation-hours, P < .01) compared with the non-mPCR group. In multivariable regression, patients tested with mPCR were less likely to receive antibiotics for ≥2 days (OR 0.5, 95% CI 0.5-0.6), chest radiographs at admission (OR 0.4, 95% CI 0.3-0.4), and more likely to be in isolation for ≥2 days (OR 2.4, 95% CI 2.1-2.8) compared with the non-mPCR group. CONCLUSIONS: Use of mPCR testing for respiratory viruses among hospitalized patients was significantly associated with decreased healthcare resource utilization, including decreased use of antibiotics and chest radiographs, and increased use of isolation precautions.

Microorganismos patógenos aislados en muestras respiratorias de niños con fibrosis quística / Isolated pathogen microorganisms in respiratory samples from children with cystic fibrosis

La fibrosis quística (FQ) se caracteriza por disfunciones en las glándulas de secreción exocrina del organismo. Las primeras manifestaciones suelen observarse en el sistema respiratorio, constituyendo una de las causas más importantes de morbimortalidad en los pacientes afectados. Los microorganismos patógenos que colonizan frecuentemente el tracto respiratorio de estos pacientes son Staphylococcus aureus, Haemophilus spp., y Pseudomonas aeruginosa. Entre noviembre de 2001 y agosto de 2004 se estudiaron 222 muestras respiratorias de pacientes con FQ de entre 4 meses y 11 años de edad. Se aislaron S. aureus (38,7%), P. aeruginosa (37,4%) y Haemophilus spp., (15,3%). En S. aureus la meticilina-resistencia fue del 25,9% y se asoció con altas resistencias a eritromicina (35,0%) y clindamicina (29,4%). El mayor porcentaje de resistencia observado en las cepas de P. aeruginosa fue frente a gentamicina (31,0%). Los aislamientos de Haemophilus spp. fueron resistentes a ampicilina (23,0%) debido a la presencia de beta-lactamasas, y a trimetoprima/sulfametoxazol (59,0%).

Cystic Fibrosis (CF) is characterized by a dysfunction of the exocrine secretion glands. The first symptoms often appear in the respiratory system which constitutes one of the most important morbimortality causes in these patients. Chronic respiratory tract colonization is caused mainly by bacteria such as Staphylococcus aureus, Haemophilus spp. and Pseudomonas aeruginosa. Respiratory samples from patients with CF (age group: 4 months to 11 years) were analyzed from November 2001 to August 2004. The most frequently isolated microorganisms were S. aureus (38.7%), P. aeruginosa (37.4%) and Haemophilus spp (15.3%). A high resistance to erithromycine (35.0%) and clindamicine (29.4%) was observed in S. aureus strains and 25.9% of them were methicillin-resistant. P. aeruginosa strains were mainly gentamicin-resistant (31.0%). The rate of ampicillin-resistant Haemophilus spp. was 23.0% and it was due to the presence of beta-lactamases, but a high trimethoprim-sulfamethoxazole resistance was observed in this microorganism (59.0%).