Sandra Galvin

Enumeration and Characterization of Antimicrobial-Resistant Escherichia coli Bacteria in Effluent from Municipal, Hospital, and Secondary Treatment Facility Sources

ABSTRACT We describe a modification of the most probable number (MPN) method for rapid enumeration of antimicrobial-resistant Escherichiacoli bacteria in aqueous environmental samples. E. coli (total and antimicrobial-resistant) bacteria were enumerated in effluent samples from a hospital (n = 17) and municipal sewers upstream (n = 5) and downstream (n = 5) from the hospital, effluent samples from throughout the treatment process (n = 4), and treated effluent samples (n = 13). Effluent downstream from the hospital contained a higher proportion of antimicrobial-resistant E. coli than that upstream from the hospital. Wastewater treatment reduced the numbers of E. coli bacteria (total and antimicrobial resistant); however, antimicrobial-resistant E. coli was not eliminated, and E. coli resistant to cefotaxime (including extended-spectrum beta-lactamase [ESBL] producers), ciprofloxacin, and cefoxitin was present in treated effluent samples.

Microbial monitoring of the hospital environment: why and how?

BACKGROUND The purpose of microbial monitoring of the inanimate environment surrounding a patient can be two-fold; to monitor hygiene standards and also to examine for the presence of specific nosocomial pathogens which may be the source of an outbreak. While both purposes involve routine culture of microorganisms, the methods used for each can differ in order to provide optimal results. The main difference between both purposes is the need for enumeration, site specificity for an aerobic colony count (ACC) for hygiene assessments, and the need to simply detect the presence or absence of multi-resistant nosocomial pathogens for infection control surveillance. AIM To access current methods used in research studies and during outbreak investigations to detect nosocomial pathogens in the inanimate environment in the clinical setting. METHODS A Pubmed search of published literature was performed. FINDINGS Microbial monitoring of the environment can involve the use of swabs, sponges, contact plates and dip slides coupled with a variety of enrichment broths and selective media. The use of molecular methods such as polymerase chain reaction (PCR) can potentially provide a faster turnaround time, resulting in the quicker implementation of infection prevention and control cleaning and disinfection regimens. However, the optimal methods for performing a microbial hygiene evaluation or detecting specific bacterial pathogens are not generally agreed. CONCLUSION There is a need for agreed standards on the optimal methods, frequency of environmental sampling and acceptable levels of surface contamination within the healthcare system.

Air and surface contamination patterns of meticillin-resistant Staphylococcus aureus on eight acute hospital wards.

BACKGROUND Meticillin-resistant Staphylococcus aureus (MRSA) can be recovered from hospital air and from environmental surfaces. This poses a potential risk of transmission to patients. AIM To investigate associations between MRSA isolates recovered from air and environmental surfaces with those from patients when undertaking extensive patient and environmental sampling. METHODS This was a prospective observational study of patients and their environment in eight wards of a 700-bed tertiary care hospital during 2010 and 2011. Sampling of patients, air and surfaces was carried out on all ward bays, with more extended environmental sampling in ward high-dependency bays and at particular times of the day. The genetic relatedness of isolates was determined by DNA microarray profiling and spa typing. FINDINGS MRSA was recovered from 30/706 (4.3%) patients and from 19/132 (14.4%) air samples. On 9/132 (6.8%) occasions both patient and air samples yielded MRSA. In 32 high-dependency bays, MRSA was recovered from 12/161 (7.4%) patients, 8/32 (25%) air samples, and 21/644 (3.3%) environmental surface samples. On 10/132 (7.6%) occasions, MRSA was isolated from air in the absence of MRSA-positive patients. Patient demographic data combined with spa typing and DNA microarray profiling revealed four likely transmission clusters, where patient and environmental isolates were deemed to be very closely related. CONCLUSION Air sampling yielded MRSA on frequent occasions, especially in high-dependency bays. Environmental and air sampling combined with patient demographic data, spa typing and DNA microarray profiling indicated the presence of clusters that were not otherwise apparent.

Enterococcus faecium of the vanA Genotype in Rural Drinking Water, Effluent, and the Aqueous Environment

ABSTRACT Total enterococci and vancomycin-resistant enterococci (VRE) were enumerated in samples of effluent (n = 50) and water (n = 167) from a number of sources. VRE were detected in the outflow of a wastewater treatment plant and in a single rural drinking water supply, suggesting potential for transmission to humans through environmental contamination.

Evaluation of screening risk and nonrisk patients for methicillin-resistant Staphylococcus aureus on admission in an acute care hospital

BACKGROUND Screening for methicillin-resistant Staphylocccus aureus (MRSA) is advocated as part of control measures, but screening all patients on admission to hospital may not be cost-effective. OBJECTIVE Our objective was to evaluate the additional yield of screening all patients on admission compared with only patients with risk factors and to assess cost aspects. METHODS A prospective, nonrandomized observational study of screening nonrisk patients ≤72 hours of admission compared with only screening patients with risk factors over 3 years in a tertiary referral hospital was conducted. We also assessed the costs of screening both groups. RESULTS A total of 48 of 892 (5%) patients was MRSA positive; 28 of 314 (9%) during year 1, 12 of 257 (5%) during year 2, and 8 of 321 (2%) during year 3. There were significantly fewer MRSA-positive patients among nonrisk compared with MRSA-risk patients: 4 of 340 (1%) versus 44 of 552 (8%), P ≤ .0001, respectively. However, screening nonrisk patients increased the number of screening samples by 62% with a proportionate increase in the costs of screening. A backward stepwise logistic regression model identified age > 70 years, diagnosis of chronic pulmonary disease, previous MRSA infection, and admission to hospital during the previous 18 months as the most important independent predictors to discriminate between MRSA-positive and MRSA-negative patients on admission (94.3% accuracy, P < .001). CONCLUSION Screening patients without risk factors increased the number of screenings and costs but resulted in few additional cases being detected. In a hospital where MRSA is endemic, targeted screening of at-risk patients on admission remains the most efficient strategy for the early identification of MRSA-positive patients.

Evaluation of vaporized hydrogen peroxide, Citrox and pH neutral Ecasol for decontamination of an enclosed area: a pilot study

Hydrogen peroxide, Ecasol and Citrox aerosols were each tested for their ability to kill a range of nosocomial pathogens. Hydrogen peroxide had the broadest microbicidal activity but operational issues limit its use. Ecasol was effective against all micro-organisms, except Clostridium difficile, while Citrox aerosols were not effective against Gram-negative bacilli.

Search and you will find: detecting extended-spectrum β-lactamase-producing Klebsiella pneumoniae from a patient's immediate environment.

pneumoniae from a Patient’s Immediate Environment Author(s): Christopher Judge, BSc; Sandra Galvin, PhD; Liam Burke, BSc; Toney Thomas, MBA; Hilary Humphreys, MD; Deirdre Fitzgerald-Hughes, PhD Source: Infection Control and Hospital Epidemiology, Vol. 34, No. 5, Special Topic Issue: The Role of the Environment in Infection Prevention (May 2013), pp. 534-536 Published by: The University of Chicago Press on behalf of The Society for Healthcare Epidemiology of America Stable URL: http://www.jstor.org/stable/10.1086/670206 . Accessed: 12/08/2013 02:40

Intervention to improve the quality of antimicrobial prescribing for urinary tract infection: a cluster randomized trial.

Background: Overuse of antimicrobial therapy in the community adds to the global spread of antimicrobial resistance, which is jeopardizing the treatment of common infections. Methods: We designed a cluster randomized complex intervention to improve antimicrobial prescribing for urinary tract infection in Irish general practice. During a 3-month baseline period, all practices received a workshop to promote consultation coding for urinary tract infections. Practices in intervention arms A and B received a second workshop with information on antimicrobial prescribing guidelines and a practice audit report (baseline data). Practices in intervention arm B received additional evidence on delayed prescribing of antimicrobials for suspected urinary tract infection. A reminder integrated into the patient management software suggested first-line treatment and, for practices in arm B, delayed prescribing. Over the 6-month intervention, practices in arms A and B received monthly audit reports of antimicrobial prescribing. Results: The proportion of antimicrobial prescribing according to guidelines for urinary tract infection increased in arms A and B relative to control (adjusted overall odds ratio [OR] 2.3, 95% confidence interval [CI] 1.7 to 3.2; arm A adjusted OR 2.7, 95% CI 1.8 to 4.1; arm B adjusted OR 2.0, 95% CI 1.3 to 3.0). An unintended increase in antimicrobial prescribing was observed in the intervention arms relative to control (arm A adjusted OR 2.2, 95% CI 1.2 to 4.0; arm B adjusted OR 1.4, 95% CI 0.9 to 2.1). Improvements in guideline-based prescribing were sustained at 5 months after the intervention. Interpretation: A complex intervention, including audit reports and reminders, improved the quality of prescribing for urinary tract infection in Irish general practice. Trial registration: ClinicalTrials.gov, no. NCT01913860

Using qualitative insights to change practice: exploring the culture of antibiotic prescribing and consumption for urinary tract infections

Objectives The aim of this paper is to explore the culture of antibiotic prescribing and consumption in the community for urinary tract infections (UTI) from the perspective of the general practitioners (GPs) and community member. Design Indepth interviews were conducted with GPs, and focus groups were held with community members. Setting General practice and community setting. Participants 15 GPs practising in rural and urban locations in Ireland participated in the indepth interviews. 6 focus groups (n=42) with participants who had direct or indirect experiences with UTI were also undertaken. Results The decision to prescribe or consume an antibiotic for a UTI is a set of complex processes including need recognition, information search and evaluation processes governed by the relationship and interactions between the GP and the patient. Different GP and patient decision-making profiles emerged emphasising the diversity and variety of general practice in real-life settings. The GP findings showed a requirement for more microbiological information on antibiotic resistance patterns to inform prescribing decisions. Focus group participants wanted a conversation with the GP about their illness and the treatment options available. Conclusions Collectively, this research identified the consultation as a priority intervention environment for stimulating change in relation to antibiotics. This paper demonstrates how qualitative research can identify the interacting processes which are instrumental to the decision to prescribe or consume an antibiotic for a suspected UTI. Qualitative research empowers researchers to investigate the what, how and why of interventions in real-life setting. Qualitative research can play a critical and instrumental role in designing behavioural change strategies with high impact on practice. The results of this research were used to design a complex intervention informed by social marketing. Trial registration number NCT01913860; Pre-results.

The antimicrobial effects of helium and helium-air plasma on Staphylococcus aureus and Clostridium difficile.

Healthcare‐associated infections (HCAI) affect 5–10% of acute hospital admissions. Environmental decontamination is an important component of all strategies to prevent HCAI as many bacterial causes survive and persist in the environment, which serve as ongoing reservoirs of infection. Current approaches such as cleaning with detergents and the use of chemical disinfectant are suboptimal. We assessed the efficacy of helium and helium–air plasma in killing Staphylococcus aureus and Clostridium difficile on a glass surface and studied the impact on bacterial cells using atomic force microscopy (AFM). Both plasma types exhibited bactericidal effects on Staph. aureus (log3·6 – >log7), with increased activity against methicillin‐resistant strains, but had a negligible effect on Cl. difficile spores (<1log). AFM demonstrated cell surface disruption. The addition of air increased the microbicidal activity of the plasma and decreased the exposure time required for an equivalent log reduction. Further evaluation of cold plasma systems is warranted with, for example, different bacteria and on surfaces more reminiscent of the health care environment as this approach has potential as an effective decontaminant.