scholarly journals Systematic Review of Measurement and Adjustment for Colonization Pressure in Studies of Methicillin-ResistantStaphylococcus aureus, Vancomycin-Resistant Enterococci, andClostridium difficileAcquisition

2011 ◽  
Vol 32 (5) ◽  
pp. 481-489 ◽  
Author(s):  
Adebola O. Ajao ◽  
Anthony D. Harris ◽  
Mary-Claire Roghmann ◽  
J. Kristie Johnson ◽  
Min Zhan ◽  
...  

Objective.Colonization pressure is an important infection control metric. The aim of this study was to describe the definition and measurement of and adjustment for colonization pressure in nosocomial-acquisition risk factor studies of methicillin-resistantStaphylococcus aureus(MRSA), vancomycin-resistant enterococci (VRE), andClostridium difficile.Methods.We performed a computerized search of studies of nosocomial MRSA, VRE, andC. difficileacquisition published before July 1, 2009, through MEDLINE. Studies were included if a study outcome was MRSA, VRE, orC. difficileacquisition; the authors identified risk factors associated with MRSA, VRE, orC. difficileacquisition; and the study measured colonization pressure.Results.The initial MEDLINE search yielded 505 articles. Sixty-six of these were identified as studies of nosocomial MRSA, VRE, orC. difficileacquisition; of these, 18 (27%) measured colonization pressure and were included in the final review. The definition of colonization pressure varied considerably between studies: the proportion of MRSA- or VRE-positive patients (5 studies), the proportion of MRSA- or VRE-positive patient-days (6 studies), or the total or mean number of MRSA-, VRE-, orC. difficile-positive patients or patient-days (7 studies) in the unit over periods of varying length. In 10 of 13 studies, colonization pressure was independently associated with MRSA, VRE, orC. difficileacquisition.Conclusion.There is a need for a simple and consistent method to quantify colonization pressure in both research and routine clinical care to accurately assess the effect of colonization pressure on cross-transmission of antibiotic-resistant bacteria.

mBio ◽  
2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Benjamin P. Howden ◽  
Kathryn E. Holt ◽  
Margaret M. C. Lam ◽  
Torsten Seemann ◽  
Susan Ballard ◽  
...  

ABSTRACTNosocomial outbreaks of vancomycin-resistantEnterococcus faecium(VREfm) are thought to occur by transmission of VREfm between patients, predicting that infection control interventions will limit cross-transmission. Despite implementation of such strategies, the incidence of VREfm infections continues to rise. We aimed to use genomics to better understand the epidemiology ofE. faeciumwithin a large hospital and investigate the reasons for failure of infection control strategies. Whole-genome sequencing was performed on 61E. faecium(36 VREfm) isolates, predominately from blood cultures collected at a single hospital between 1998 and 2009, and on fivevanB-positive anaerobic commensal bacteria isolated from human feces. Phylogenomic analysis and precise mapping of thevanBgene, which contains the Tn1549transposon, showed that at least 18 of the 36 VREfm isolates had acquired the transposon via independent insertion events, indicatingde novogeneration of VREfm rather than cross-transmission. Furthermore, Tn1549sequences found in 15 of the 36 VREfm isolates were the same as the Tn1549sequence from one of the gut anaerobes. National and international comparatorE. faeciumisolates were phylogenetically interspersed with isolates from our hospital, suggesting that our findings might be globally representative. These data demonstrate that VREfm generation within a patient is common, presumably occurring in the human bowel during antibiotic therapy, and help explain our inability to reduce VREfm infections. A recommendation from our findings is that infection control practices should include screening patients for specific hospital clones of vancomycin-susceptibleE. faeciumrather than just VREfm.IMPORTANCEEnterococcus faeciumis an increasingly important human pathogen causing predominantly antibiotic-resistant infections in hospitalized patients. Large amounts of health care funding are spent trying to control antibiotic-resistant bacteria in hospitals globally, yet in many institutions around the world, vancomycin-resistantE. faecium(VREfm) infections continue to rise. The new findings from this study help explain the failures of our current approaches to controllingvanBVREfm in health care institutions. Given the importance of this bacterium as a cause of hospital-acquired infections and the difficulties faced by infection control units in trying to prevent colonization in their institutions, the novel findings from this study provide evidence that a new approach to controlling VREfm in hospitals is required. In particular, more attention should be given to understanding the epidemiology of hospital-adapted vancomycin-susceptibleE. faecium, and patients at higher risk forde novogeneration of VREfm need to be identified and optimally managed.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Daniel T. Grima ◽  
Glenn F. Webb ◽  
Erika M. C. D'Agata

Introduction.Clostridium difficile-associated disease (CDAD) is treated using antibiotics, which often leads to the emergence of antibiotic-resistant bacteria such as vancomycin-resistant enterococci (VRE). This study estimated the impact of a non antibiotic treatment for CDAD on VRE prevalence.Methods. A previously published model describing the impact of in-hospital antibiotic use on VRE prevalence was adapted to include CDAD treatment. Simulations compared the prevalence of VRE when nonantibiotic versus antibiotic therapy was used.Results. Nonantibiotic treatment in 50% of CDAD patients resulted in an 18% relative reduction in the prevalence of VRE colonization compared with antibiotic use only. Sensitivity analysis found the model to be most sensitive to rates of antibiotic initiation and discontinuation, prevalence of VRE in admitted patients, length of stay of colonized patients, probability of CDAD acquisition, and hand-washing compliance.Conclusion. Nonantibiotic treatment of patients hospitalized with CDAD may significantly reduce the incidence of VRE colonization.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 466
Author(s):  
Herbert Galler ◽  
Josefa Luxner ◽  
Christian Petternel ◽  
Franz F. Reinthaler ◽  
Juliana Habib ◽  
...  

In recent years, antibiotic-resistant bacteria with an impact on human health, such as extended spectrum β-lactamase (ESBL)-containing Enterobacteriaceae, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE), have become more common in food. This is due to the use of antibiotics in animal husbandry, which leads to the promotion of antibiotic resistance and thus also makes food a source of such resistant bacteria. Most studies dealing with this issue usually focus on the animals or processed food products to examine the antibiotic resistant bacteria. This study investigated the intestine as another main habitat besides the skin for multiresistant bacteria. For this purpose, faeces samples were taken directly from the intestines of swine (n = 71) and broiler (n = 100) during the slaughter process and analysed. All samples were from animals fed in Austria and slaughtered in Austrian slaughterhouses for food production. The samples were examined for the presence of ESBL-producing Enterobacteriaceae, MRSA, MRCoNS and VRE. The resistance genes of the isolated bacteria were detected and sequenced by PCR. Phenotypic ESBL-producing Escherichia coli could be isolated in 10% of broiler casings (10 out of 100) and 43.6% of swine casings (31 out of 71). In line with previous studies, the results of this study showed that CTX-M-1 was the dominant ESBL produced by E. coli from swine (n = 25, 83.3%) and SHV-12 from broilers (n = 13, 81.3%). Overall, the frequency of positive samples with multidrug-resistant bacteria was lower than in most comparable studies focusing on meat products.


2015 ◽  
Vol 36 (11) ◽  
pp. 1275-1282 ◽  
Author(s):  
Rupak Datta ◽  
Shawn Brown ◽  
Vinh Q. Nguyen ◽  
Chenghua Cao ◽  
John Billimek ◽  
...  

OBJECTIVETo assess the time-dependent exposure of California healthcare facilities to patients harboring methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum β-lactamase (ESBL)–producing Escherichia coli and Klebsiella pneumoniae, and Clostridium difficile infection (CDI) upon discharge from 1 hospital.METHODSRetrospective multiple-cohort study of adults discharged from 1 hospital in 2005–2009, counting hospitals, nursing homes, cities, and counties in which carriers were readmitted, and comparing the number and length of stay of readmissions and the number of distinct readmission facilities among carriers versus noncarriers.RESULTSWe evaluated 45,772 inpatients including those with MRSA (N=1,198), VRE (N=547), ESBL (N=121), and CDI (N=300). Within 1 year of discharge, MRSA, VRE, and ESBL carriers exposed 137, 117, and 45 hospitals and 103, 83, and 37 nursing homes, generating 58,804, 33,486, and 15,508 total exposure-days, respectively. Within 90 days of discharge, CDI patients exposed 36 hospitals and 35 nursing homes, generating 7,318 total exposure-days. Compared with noncarriers, carriers had more readmissions to hospitals (MRSA:1.8 vs 0.9/patient; VRE: 2.6 vs 0.9; ESBL: 2.3 vs 0.9; CDI: 0.8 vs 0.4; all P<.001) and nursing homes (MRSA: 0.4 vs 0.1/patient; VRE: 0.7 vs 0.1; ESBL: 0.7 vs 0.1; CDI: 0.3 vs 0.1; all P<.001) and longer hospital readmissions (MRSA: 8.9 vs 7.3 days; VRE: 8.9 vs 7.4; ESBL: 9.6 vs 7.5; CDI: 12.3 vs 8.2; all P<.01).CONCLUSIONSPatients harboring antibiotic-resistant pathogens rapidly expose numerous facilities during readmissions; regional containment strategies are needed.Infect. Control Hosp. Epidemiol. 2015;36(11):1275–1282


2019 ◽  
Vol 20 (6) ◽  
pp. 1255 ◽  
Author(s):  
Ana Monserrat-Martinez ◽  
Yann Gambin ◽  
Emma Sierecki

Since their discovery in the early 20th century, antibiotics have been used as the primary weapon against bacterial infections. Due to their prophylactic effect, they are also used as part of the cocktail of drugs given to treat complex diseases such as cancer or during surgery, in order to prevent infection. This has resulted in a decrease of mortality from infectious diseases and an increase in life expectancy in the last 100 years. However, as a consequence of administering antibiotics broadly to the population and sometimes misusing them, antibiotic-resistant bacteria have appeared. The emergence of resistant strains is a global health threat to humanity. Highly-resistant bacteria like Staphylococcus aureus (methicillin-resistant) or Enterococcus faecium (vancomycin-resistant) have led to complications in intensive care units, increasing medical costs and putting patient lives at risk. The appearance of these resistant strains together with the difficulty in finding new antimicrobials has alarmed the scientific community. Most of the strategies currently employed to develop new antibiotics point towards novel approaches for drug design based on prodrugs or rational design of new molecules. However, targeting crucial bacterial processes by these means will keep creating evolutionary pressure towards drug resistance. In this review, we discuss antibiotic resistance and new options for antibiotic discovery, focusing in particular on new alternatives aiming to disarm the bacteria or empower the host to avoid disease onset.


2020 ◽  
Vol 8 (10) ◽  
pp. 1487
Author(s):  
Marta Aires-de-Sousa ◽  
Claudine Fournier ◽  
Elizeth Lopes ◽  
Hermínia de Lencastre ◽  
Patrice Nordmann ◽  
...  

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.


1998 ◽  
Vol 158 (10) ◽  
pp. 1127 ◽  
Author(s):  
Marc J. M. Bonten ◽  
Sarah Slaughter ◽  
Anton W. Ambergen ◽  
Mary K. Hayden ◽  
Jean van Voorhis ◽  
...  

Author(s):  
Sneha Kalasseril Girijan ◽  
Devika Pillai

Abstract Antibiotic resistance has become a major threat to human health around the world, but its spread through the aquatic environment has been often overlooked. This study aimed to determine the occurrence of vancomycin-resistant Staphylococcus aureus in hospital wastewaters and their transmission into public water bodies in Kerala, India. A total of 113 S. aureus were isolated from three hospital effluents in Kerala, India. Standard disc diffusion and the strip method were used for antibiotic susceptibility testing and minimum inhibitory concentration detection. Plasmid-mediated vancomycin resistance was confirmed by plasmid curing and conjugation; resistant genes were detected by the polymerase chain reaction (PCR). Nearly 76% of S. aureus isolates were resistant to β-lactams, chloramphenicol, macrolides, aminoglycosides, and glycopeptide class of antibiotics. Among the vancomycin-resistant Staphylococcus aureus (VRSA) isolates, the prevalence rates of vanA and vanB resistance-encoding genes were 46.5 and 59.3%, respectively. Through the broth mating method, vanA gene was successfully transferred from VRSA donor to vancomycin-sensitive S. aureus. The study strongly indicates the contamination of water bodies with antibiotic-resistant bacteria from hospital discharges, their dissemination and possible transfer to microbes in the aquatic environment, posing a serious threat for public health.


2019 ◽  
Vol 65 (3) ◽  
pp. 483-490
Author(s):  
Dorottya Franyó ◽  
Balázs Kocsi ◽  
Evelin Erzsébet Bukta ◽  
Judit Szabó ◽  
Zsuzsanna Dombrádi

Abstract Excessive use of antibiotics contributes to the selection of resistant bacteria and intestinal colonization with multiresistant pathogens poses a risk factor for subsequent infections. The present study assessed vancomycin-resistant enterococci (VRE) carriage rates in patients admitted to our tertiary care hospital. Stool samples sent for routine culturing were screened with vancomycin containing solid or broth enrichment media. VRE isolates were identified with matrix-assisted laser desorption/ionization-time of flight mass spectrometry and antibiotic susceptibilities were tested by E-test. Vancomycin resistance genes were detected by polymerase chain reaction. Medical records of carriers were examined for suspected risk factors for colonization. Altogether 3025 stool specimens were analyzed. Solid media identified a VRE carriage rate of 2.2% while broth enrichment detected 5.8%. Seventy percent of the isolates were Enterococcus faecium. VanB genotype was detected in 38.2%, VanA in 37.3%, VanC1 in 22.6%, and VanC2 in 1.9%. All VRE were sensitive to linezolid, daptomycin, and tigecycline. Collective risk factors for carriage were diabetes, normal flora absence, Clostridioides difficile positivity, longer hospital stay, and advanced age. 78.5% of the carriers received antibiotic therapy which was metronidazole in most cases (47.3%). We recommend regular screening of risk groups such as patients with diabetes, history of recent hospitalization, or former C. difficile infection as an imperative step for preventing VRE dissemination.


2020 ◽  
Vol 18 (6) ◽  
pp. 911-924
Author(s):  
Silvia Monteiro ◽  
Ricardo Santos

Abstract Treated wastewater discharged into the environment or reused in different activities can be a major vehicle for the transmission of antibiotic-resistant bacteria and antibiotic-resistance genes. In this study, environmental and wastewater samples, collected at different stages of treatment, were studied to identify the possibility of a positive selection of antibiotic-resistant organisms in wastewater treatment plants (WWTPs). Enterococci were isolated, characterized into the main human species, and subjected to the Kirby–Bauer test using seven antibiotics (five classes): ampicillin, chloramphenicol, ciprofloxacin, gentamicin, linezolid, tetracycline, and vancomycin. Furthermore, vancomycin-resistant enterococci (VRE), a major cause of nosocomial infection, was identified, and the genes vanA and vanB detected directly in the samples and in all confirmed VRE. Data showed that WWTPs were able to reduce the levels of antibiotic resistance, although 72% of the disinfected wastewaters still presented antibiotic-resistant enterococci. VRE were detected in 6% of the samples, including in reclaimed waters. UV disinfection was not effective at removing VRE and multiple antibiotic-resistant (MAR) enterococci, most commonly Enterococcus faecalis. The use of reclaimed water containing VRE and MAR enterococci in crop production, irrigation of urban gardens, and street cleaning increases immensely the potential risk to human health.


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