Prevalence and predictors of MRSA,ESBL, and VRE colonization in the ambulatory IBD population

Background and aimsInflammatory bowel disease (IBD) patients may be at increased risk of acquiring antibiotic-resistant organisms (ARO). We sought to determine the prevalence of colonization of methicillin-resistant Staphylococcus aureus (MRSA), Enterobacteriaceae containing extended spectrum beta-lactamases (ESBL), and vancomycin-resistant enterococi (VRE) among ambulatory IBD patients.MethodsWe recruited consecutive IBD patients from clinics (n = 306) and 3 groups of non-IBD controls from our colon cancer screening program (n = 67), the family medicine clinic (n = 190); and the emergency department (n = 428) from the same medical center in Toronto. We obtained nasal and rectal swabs for MRSA, ESBL, and VRE and ascertained risk factors for colonization.ResultsCompared to non-IBD controls, IBD patients had similar prevalence of colonization with MRSA (1.5% vs. 1.6%), VRE (0% vs. 0%), and ESBL (9.0 vs. 11.1%). Antibiotic use in the prior 3 months was a risk factor for MRSA (OR, 3.07; 95% CI: 1.10–8.54), particularly metronidazole. Moreover, gastric acid suppression was associated with increased risk of MRSA colonization (adjusted OR, 7.12; 95% CI: 1.07–47.4). Predictive risk factors for ESBL included hospitalization in the past 12 months (OR, 2.04, 95% CI: 1.05–3.95); treatment with antibiotics it the past 3 months (OR, 2.66; 95% CI: 1.37–5.18), particularly prior treatment with vancomycin or cephalosporins.ConclusionsAmbulatory IBD patients have similar prevalence of MRSA, ESBL and VRE compared to non-IBD controls. This finding suggests that the increased MRSA and VRE prevalence observed in hospitalized IBD patients is acquired in-hospital rather than in the outpatient setting.     

Prevalence and incidence of antimicrobial-resistant organisms among hospitalized inflammatory bowel disease patients

BACKGROUND:

Patients with inflammatory bowel disease (IBD) experience frequent hospitalizations and use of immunosuppressive medications, which may predispose them to colonization with antimicrobial-resistant organisms (ARO).

OBJECTIVE:

To determine the prevalence of ARO colonization on admission to hospital and the incidence of infection during hospitalization among hospitalized IBD patients.

METHODS:

A chart review comparing the prevalence of colonization and incidence of infection with methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL) in hospitalized IBD patients with those of non-IBD controls was performed.

RESULTS:

On admission, there were no significant differences between IBD inpatients and controls in the prevalence of colonization of methicillin-resistant S aureus (1.0% versus 1.2%; P=0.74), vancomycin-resistant enterococci (0.2% versus 0%; P=1.0) or ESBL (4.1% versus 5.5%; P=0.33). Pooling data from historical clinic-based cohorts, IBD patients were more likely than controls to have ESBL colonization (19% versus 6.6%; P<0.05). Antibiotic use on admission was associated with ESBL colonization among IBD inpatients (OR 4.2 [95% CI 1.4 to 12.6]). The incidence of ARO infections during hospitalization was not significantly different between IBD patients and controls. Among IBD patients who acquired ARO infections during hospitalizations, the mean time interval from admission to infection was shorter for those who were already colonized with ARO on admission.

CONCLUSIONS:

This particular population of hospitalized IBD patients was not shown to have a higher prevalence or incidence of ARO colonization or infection compared with non-IBD inpatients.     

Colonization of skilled-care facility residents with antimicrobial-resistant pathogens

OBJECTIVES: To determine the frequency of and risk factors for colonization of skilled-care unit residents by several antimicrobial-resistant bacterial species, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE), or extended-spectrum-beta-lactamase-producing (ESBL-producing) (ceftazidime resistant) Klebsiella pneumoniae or Escherichia coli. DESIGN: Point-prevalence survey and medical record review. SETTING: The skilled-care units in one healthcare facility. PARTICIPANTS: 120 skilled-care unit residents. MEASUREMENTS: Colonization by each of the four antimicrobial-resistant pathogens during a point-prevalence survey, using rectal, nasal, gastrostomy-tube site, wound, and axillary cultures, June 1-3, 1998; 117 (98%) had at least one swab collected and 114 (95%) had a rectal swab collected. Demographic and clinical characteristics were evaluated as risk factors for colonization. All isolates were strain typed by pulsed-field gel electrophoresis of total genomic deoxyribonucleic acid. RESULTS: Of 117 participants, 50 (43%) were culture positive for > or =1 antimicrobial-resistant pathogen: MRSA (24%), ESBL-producing K. pneumoniae (18%) or E. coli (15%), and VRE (3.5%). Of 50 residents culture positive for any of these four antimicrobial-resistant species, 13 (26%) were colonized by more than one resistant species; only three (6%) were on contact-isolation precautions at the time of the prevalence survey. Risk factors for colonization varied by pathogen: total dependence on healthcare workers (HCWs) for activities of daily living (ADLs) and antimicrobial receipt for MRSA, total dependence on HCWs for ADLs for ESBL-producing K. pneumoniae, and antimicrobial receipt for VRE. No significant risk factors were identified for colonization by ESBL-producing E. coli. Among colonized patients, there was a limited number of strain types for MRSA (24 patients, 4 strain types) and ESBL-producing K. pneumoniae (21 patients, 3 strain types), and a high proportion of unique strain types for VRE (4 patients, 4 strain types) and FSBL-producing E. coli (17 patients, 10 strain types). CONCLUSION: A large unrecognized reservoir of skilled-care-unit residents was colonized by antimicrobial-resistant pathogens, and co-colonization by more than one target species was common. To prevent transmission of antimicrobial-resistant pathogens in long-term care facilities in which residents have high rates of colonization, infection-control strategies may need to be modified. Potential modifications include enhanced infection-control strategies, such as universal gloving for all or high-risk residents, or screening of high-risk residents, such as those with total dependence on HCWs for ADLs or recent antimicrobial receipt, and initiation of contact-isolation precautions for colonized residents.     

Effects of daily bathing with chlorhexidine and acquired infection of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus: a meta-analysis

Objective

Chlorhexidine gluconate (CHG) is a common and safe antimicrobial agent and has been used widely in hand hygiene and skin disinfection; however, whether daily bathing with CHG results in the reduced acquired infection of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) remains inconclusive.

Methods

We did a meta-analysis searching PubMed, Embase and the Cochrane Central Register database for available studies. Primary outcomes were acquired infection of MRSA, VRE.

Results

In all, twelve articles were available in this review. We found that daily application of chlorhexidine bathing would significantly low the acquired colonization of MRSA [incidence rate ratio (IRR) =0.58, 95% confidence interval (CI): 0.41-0.82] or VRE (IRR =0.51, 95% CI: 0.36-0.73). Remarkably, the using of CHG bathing would significantly reduce the MRSA infection (IRR =0.56, 95% CI: 0.37-0.85), MRSA ventilator associated pneumonia (VAP) (IRR =0.22, 95% CI: 0.07-0.64) and VRE infection (IRR =0.57, 95% CI: 0.33-0.97). No significant publication bias was found in this meta-analysis.

Conclusions

The application of CHG bathing would significantly decrease acquired infection of MRSA or VRE, which may be an important complementary intervention to barrier precautions.KEY WORDS : Chlorhexidine, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE)     

Prediction rules to identify patients with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci upon hospital admission

BACKGROUND: In 2003, the Society of Healthcare Epidemiology of America (SHEA) recommended surveillance cultures upon hospital admission for patients at high risk for carriage of vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to assess the validity of factors from past medical history in defining patients at high risk for subsequent positive cultures with VRE or MRSA upon hospital admission. METHODS: Subjects were adult inpatients admitted to nonintensive care wards of the index hospital during 2001-2002. Cases had MRSA or VRE positive clinical cultures within 48 hours of hospital admission. Patients with previous history of MRSA or VRE were excluded. RESULTS: Nineteen thousand three hundred ninety-nine patients were included, with 273 cases of VRE or MRSA. Previous admission within 1 year of current admission had a sensitivity of 56.8% and a specificity of 88.4% for predicting a case of MRSA or VRE. Individually, the sensitivity and specificity for admission within the past year were 50.5% and 88.4%, respectively, for MRSA and 76.9% and 88.4%, respectively, for VRE. CONCLUSIONS: Patients with a previous hospital admission represent a high-risk population for positive culture for VRE and MRSA and may be a group of which active surveillance is indicated.     

Long-term care facilities as sources of antibiotic-resistant nosocomial pathogens

Long-term care facilities house individuals that have usually been transferred from acute-care institutions. For this reason, carriage of methicillin-resistant Staphylococcus aureus (MRSA), resistant Gram-negative bacilli and vancomycin-resistant enterococci (VRE) is relatively frequent. As these patients are readmitted to acute-care institutions, they reintroduce these organisms into those settings. It is notable that studies of these resistant organisms in long-term care facilities demonstrate little transfer between patients. Transmission of these bacteria and the development of infection in nursing homes are both uncommon events. Resources are best devoted to infection-control basics than to isolation of patients colonized or infected with these organisms.     

Prevalence of antibiotic-resistant bacteria in residents of nursing homes in a Swedish municipality: Healthcare staff knowledge of and adherence to principles of basic infection prevention

Abstract Background: The aims of this study were to investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in residents living in Swedish nursing homes, and if carriage of resistant bacteria was related to antibiotic treatment, other risk factors, and/or staff's adherence to guidelines for infection control. Methods: Five hundred and sixty residents from 9 nursing homes on a total of 67 wards participated in the study and had microbiological cultures taken. Faecal samples were obtained from 495 residents (88.3%). ESBL-positive residents were followed for 2 y with repeated sampling. Two hundred and ninety-six staff members were interviewed and observed regarding familiarity with and adherence to infection control guidelines. Results: No resident was positive for MRSA or VRE. Fifteen of the residents were found to be ESBL-positive. Residents living on wards where ESBL-positive residents were identified had been treated more frequently with antibiotics (42%), compared to those on wards where no residents with ESBL were found (28%; p =?0.02). ESBL-positive Escherichia coli isolates from residents living in adjacent rooms were found to be closely genetically related when analysed by pulsed-field gel electrophoresis, indicating transmission between residents. Staff adherence to infection control guidelines sometimes revealed shortcomings, but no significant differences regarding compliance to the guidelines could be found. Conclusion: Carriage of resistant bacteria was uncommon and only ESBL-producing Enterobacteriaceae were identified in Swedish nursing homes. Usage of antibiotics was higher on wards where ESBL-positive residents were detected and there was an indication of transmission of ESBL between residents.     

Methicillin-resistant Staphylococcus aureus: A public health issue with economic consequences

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) has become endemic worldwide in hospitals, and community-associated MRSA is spreading into the community at large. OBJECTIVES: To estimate the current cost of MRSA in Canada and to assess the magnitude of this public health issue. METHODS: An extensive review of the literature was conducted to gather epidemiology, health care resource utilization and cost data for MRSA in Canadian settings. The current MRSA burden was estimated using available cost data and the most recent epidemiology data. RESULTS: The rate of MRSA in Canadian hospitals increased from 0.46 to 5.90 per 1000 admissions between 1995 and 2004, while community-associated MRSA continued to spread into the community. Patients harbouring MRSA required prolonged hospitalization (average 26 days of isolation per patient), special control measures, expensive treatments and extensive surveillance. Total cost per infected MRSA patient averaged $12,216, with hospitalization being the major cost driver (81%), followed by barrier precautions (13%), antimicrobial therapy (4%) and laboratory investigations (2%). The most recent epidemiological data, combined with available cost data, suggest that direct health care cost attributable to MRSA in Canada, including cost for management of MRSA-infected and-colonized patients and MRSA infrastructure, averaged $82 million in 2004 and could reach $129 million in 2010. CONCLUSION: MRSA is a costly public health issue that needs to be tackled if the growing burden of this disease in Canadian hospitals and in the community is to be limited.     

Risk of acquiring antibiotic-resistant bacteria from prior room occupants

BACKGROUND: Environmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) occurs during the care of patients harboring these organisms and may increase the risk of transmission to subsequent room occupants. METHODS: Twenty-month retrospective cohort study of patients admitted to 8 intensive care units performing routine admission and weekly screening for MRSA and VRE. We assessed the relative odds of acquisition among patients admitted to rooms in which the most recent occupants were MRSA positive or VRE positive, compared with patients admitted to other rooms. RESULTS: Of 11 528 intensive care unit room stays, 10 151 occupants were eligible to acquire MRSA, and 10 349 were eligible to acquire VRE. Among patients whose prior room occupant was MRSA positive, 3.9% acquired MRSA, compared with 2.9% of patients whose prior room occupant was MRSA negative (adjusted odds ratio, 1.4; P = .04). VRE, Among patients whose prior room occupant was VRE positive, these values were 4.5% and 2.8% respectively (adjusted odds ratio, 1.4; P = .02). These excess risks accounted for 5.1% of all incident MRSA cases and 6.8% of all incident VRE cases, with a population attributable risk among exposed patients of less than 2% for either organism. Acquisition was significantly associated with longer post-intensive care unit length of stay. CONCLUSIONS: Admission to a room previously occupied by an MRSA-positive patient or a VRE-positive patient significantly increased the odds of acquisition for MRSA and VRE. However, this route of transmission was a minor contributor to overall transmission. The effect of current cleaning practices in reducing the risk to the observed levels and the potential for further reduction are unknown.     

Evaluation of a successful vancomycin-resistant Enterococcus prevention intervention in a community of health care facilities

BACKGROUND: In April 1997, vancomycin-resistant enterococci (VRE) emerged in several health care facilities in the Siouxland region and a VRE Task Force was formed. From 1997 through 1999, an evaluation of VRE prevalence at 30 facilities was performed. METHODS: In 1999, we conducted a survey and focus groups of health care workers to address initial reactions to VRE, feasibility of the Task Force recommendations, and lessons learned. RESULTS: Personnel at 29 (97%) facilities surveyed completed the questionnaire, and 15 health care workers from 11 facilities participated in 5 focus groups. The outcomes of expanded education and improved awareness of VRE for patients and health care workers were ranked the No. 1 priority overall and by long-term care facility personnel. Respondents agreed that Task Force recommendation adherence had significantly improved infection control (83%) and that the Task Force was an appropriate mechanism to coordinate infection control efforts (90%). Focus groups commented that it was most difficult to educate family members about VRE; they expressed concern about variation between VRE policies, especially between acute care and long-term care facilities, and about the quality of life of isolated patients. CONCLUSIONS: Our data illustrate that this intervention has been far-reaching and include the development of a health care infrastructure that may be used as a model to address additional health care issues (eg, emerging pathogens or biological threats).     

The relationship between hospital infection surveillance and control activities and antibiotic-resistant pathogen rates

BACKGROUND: Antibiotic-resistant pathogen rates are rising in Canada and the United States with significant health and economic costs. The examination of the relationship of surveillance and control activities in hospitals with rates of nosocomial methicillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile -associated diarrhea (CDAD), and vancomycin-resistant Enterococcus (VRE) may identify strategies for controlling this growing problem. METHODS: Surveys were sent to infection control programs in hospitals that participated in an earlier survey of infection control practices in Canadian acute care hospitals. RESULTS: One hundred twenty of 145 (82.8%) hospitals responded to the survey. The mean MRSA rate was 2.0 (SD 2.9) per 1000 admissions, the mean CDAD rate was 3.8 (SD 4.3), and the mean VRE rate was 0.4 (SD 1.5). Multiple stepwise regression analysis found that hospitals that reported infection rates by specific risk groups ( r = -0.27, P < .01) and that kept attendance records of infection control teaching activities ( r = -0.23, P < .01) were associated with lower MRSA rates. Multiple stepwise regression analysis found that larger hospitals ( r = 0.25, P < .01) and hospitals at which infection control committees or staff had the direct authority to close a ward or unit to further admissions because of outbreaks ( r = 0.22, P < .05) were associated with higher CDAD rates. Multiple logistic regression analysis found that larger hospitals (OR, 1.6; 95% CI, 1.2-2.0; P = .003) and teaching hospitals (OR, 3.7 95% CI, 1.2-11.8; P = .02) were associated with the presence of VRE. Hospitals were less likely to have VRE when infection control staff frequently contacted physicians and nurses for reports of new infections (OR, 0.5; 95% CI, 0.3-0.7; P = .02) and there were in-service programs for updating nursing and ancillary staff on current infection control practices (OR, 0.2; 95% CI, 0.1-0.7; P = .01). CONCLUSION: Surveillance and control activities were associated with MRSA and CDAD rates and the presence of VRE. Surveillance and control activities might be especially beneficial in large and teaching hospitals.     

Prevention and control of methicillin-resistant Staphylococcus aureus infections

PURPOSE OF REVIEW: This article reviews many recent publications relevant to the prevention and control of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection. RECENT FINDINGS: Higher risk-adjusted costs and mortality have been found for MRSA infections than for methicillin-susceptible S. aureus infections confirming their epidemiologic importance. Staphylococcal cassette chromosome mec, the genetic basis for MRSA, does not develop in methicillin-susceptible S. aureus exposed to antimicrobials. Instead virtually all patients acquire MRSA via spread. Nevertheless, antibiotic therapy provides a selective advantage for such spread, especially within healthcare settings where antimicrobial therapy is most frequent. Several studies have suggested better control of MRSA through antibiotic control, but far more studies have reported control using surveillance cultures and contact precautions for preventing spread (rather than just using standard precautions). More rapid detection of MRSA (within 6 h) has been reported using polymerase chain reaction, but studies using this method to reduce spread have not yet been published. A structured survey of research methods used regarding MRSA control noted that many studies had methodologic shortcomings (for example, none was a randomized trial), but nevertheless concluded that active detection and isolation work should be used. A Society for Healthcare Epidemiology of America guideline emphasized the same approach noting that scores of studies on multiple continents had reported success with this approach, with best results in several northern-European countries where all facilities used it routinely. SUMMARY: Improved MRSA control is possible by detecting and isolating colonized patients.     

Colonization of pressure ulcers by multidrug-resistant microorganisms in patients receiving home care

Colonization and/or infection with multidrug-resistant microorganisms (MDRO) of pressure ulcers in patients receiving care at home have seldom been investigated. The objective of this study was to assess the prevalence of MDRO colonization in pressure ulcers of patients receiving home care in Palermo, Italy. Vancomycin-resistant Enterococcus (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and multidrug-resistant Gram-negative bacilli (MDRGN) were isolated, identified, and characterized from pressure ulcers and selected home environment surfaces. Thirty-two patients were enrolled, of whom 12 were under antimicrobial therapy. Five patients had been admitted to hospital in the preceding year. Nineteen patients tested positive for 1 or more MDROs. In particular, 1 patient was colonized by a vanA-containing strain of VRE, 5 by MRSA, and 17 by MDRGN of different species. Our findings suggest that pressure ulcers in home care patients could play a role in bringing MDROs into the community setting.     

β-lactamase producing enterobacteria isolated from surveillance swabs of patients in a Cardiac Intensive Care Unit in Rio de Janeiro,Brazil

There is a high incidence of infections caused by betalactamase-producing Gram-negative microorganisms in Brazil. These organisms are of clinical and epidemiological importance, since their mobile genetic elements facilitate cross-infection. The present study was conducted in sentinel rectal swabs from patients admitted to a cardiac surgery hospital in Rio de Janeiro, from January through December 2007, in a consecutive manner. The aim of the study was to characterize the genotype and phenotype of these isolates from colonized patients. Biochemical tests, antimicrobial susceptibility tests, a confirmatory test for the expression of extended spectrum betalactamase (ESBL) production and polymerase chain reaction for the blaTEM, blaSHV, CTX-M1, Toho-1 and AmpC genes were performed at the University Hospital of Universidade do Estado do Rio de Janeiro (UERJ). The most frequently isolated bacteria were Escherichia coli 9/41 (21.95%) and Klebsiella pneumoniae 14/41 (34.1%). In 24/41 (58%), the ESBL genotype was confirmed. The most prevalent genes in samples that expressed ESBL were blaTEM 13/24 (54%), AmpC 12/24 (50%), blaSHV 6/24 (25%), CTX-M1 7/24 (29%), and Toho-1 6/24 (25%). Of these, 14/24 (58%) presented more than one genotype for the tested primers. In nine (37%) samples other than E. coli, K. pneumoniae or Proteus spp., the phenotype for ESBL was found and confirmed by PCR. The most sensitive substrate in the approximation test in ESBL positive samples was ceftriaxone (83%). Fifty percent of the samples expressed AmpC were associated with other genes. Intermediate susceptibility to ertapenem was found in 2/41 (5%).     

Methicillin-resistant Staphylococcus aureus. Management of asymptomatic colonization and outbreaks of infection in long-term care

Asymptomatic colonization with methicillin-resistant Staphylococcus aureus (MRSA) is common in long-term care facilities, but the burden of symptomatic infection appears to be low. Patients known to be MRSA carriers should not be refused admission, and routine cultures to identify carriers are not warranted. In the absence of symptomatic MRSA, no measures beyond routine infection control and standard precautions are necessary. Increased rates of infection should prompt investigation of a potential outbreak and initiation of more drastic infection-control measures. During an outbreak, both infected and colonized residents should be isolated until transmission has been halted. Using short-term nasal application of mupirocin ointment for MRSA-colonized residents and staff implicated in the outbreak may help break the chain of transmission.     

Vancomycin-resistant enterococci in intensive care units: high frequency of stool carriage during a non-outbreak period.

BACKGROUND: We aimed to define the epidemiological associations of vancomycin-resistant enterococci (VRE) in intensive care units (ICUs) during a non-outbreak period by examining prevalence, risk factors for colonization, frequency of acquisition, and molecular strain types. DESIGN: A prospective cohort design was followed. Consecutive patient admissions to 2 surgical ICUs at a tertiary care hospital were enrolled. The main outcome measures were results of serial surveillance cultures screened for VRE. RESULTS: Of 290 patients enrolled, 35 (12%) had colonization with VRE on admission. The VRE colonization or infection had been previously detected by clinical cultures in only 4 of these patients. Using logistic regression, VRE colonization at the time of ICU admission was associated with second- and third-generation cephalosporins (odds ratio [OR] = 6.0, P<.0001), length of stay prior to surgical ICU admission (OR = 1.06, P = .001) greater than 1 prior ICU stay (OR = 9.6, P = .002), and a history of solid-organ transplantation (OR = 3.8, P = .021). Eleven (12.8%) of 78 patients with follow-up cultures acquired VRE. By pulsed-field gel electrophoresis, 2 strains predominated, one of which was associated with an overt outbreak on a non-ICU ward near the end of the study period. CONCLUSIONS: Colonization was common and usually not recognized by clinical culture. Most patients who had colonization with VRE and were on the surgical ICU acquired VRE prior to surgical ICU entry. Exposure to second- and third-generation cephalosporins, but not vancomycin, was an independent risk factor for colonization. Prospective surveillance of hospitalized patients may yield useful insights about the dissemination of nosocomial VRE beyond what is appreciated by clinical cultures alone.     

Different Trends of MRSA and VRE in a German Hospital, 1999–2005

Abstract Some of the clinically most menacing nosocomial pathogens are Methicillin-resistent Staphylococcus aureus (MRSA) and Vancomycin-resistent Enterococcus (VRE). During the last years both pathogens showed dramatic increases in colonization and infection rates in Germany. This study covers all patients positively tested for MRSA and VRE in a German University Hospital from 1999–2005. About 1,179 MRSA cases and 116 VRE cases have been reported. VRE was significantly associated with less infection, female gender, more death and higher nosocomial acquisition than MRSA. While MRSA rates increased impressively from 1999 to 2005 VRE rates decreased clearly. Assuming that compliance with hygienic measures is similar in dealing with MRSA and VRE it is quite unclear why these two major pathogens differ so much in their trends. One possibility is that the MRSA problem has been caused by an increasing share of nonnosocomially acquired MRSA.     

Antibiotic-resistant organisms among long-term care facility residents on admission to an inpatient geriatrics unit: Retrospective and prospective surveillance

BACKGROUND: There is limited information about antibiotic-resistant organisms in community long-term care facilities (LTCFs). The objective of this study was to obtain data on resistant organisms in residents from community LTCFs admitted to an inpatient acute geriatrics service (AGS). METHODS: Two studies were performed. In the first study, bacteriology records of all admissions to the AGS for the period from November 1, 1998, through June 30, 2000, were reviewed for resistant organisms (methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant enterococci [VRE], and resistant gram-negative bacilli). In the second study, residents admitted to the AGS during a 2-month period (N = 92 admissions) had surveillance cultures (nares, gastrostomy site, wounds, and urine) for resistant organisms done within 72 hours of admission. RESULTS: In the retrospective study, there were 727 admissions, of which 437 (60%) had 928 cultures within 72 hours of admission; 590 (64%) cultures grew 1 or more pathogens. Urine (65%) and blood (26%) cultures accounted for 91% of all cultures done. Rates of resistance by culture site were as follows: urine (resistant organism in 16.6% of 373 cultures), blood (6.7% of 60 cultures), wound (52% of 23 cultures), and sputum (40% of 20 cultures). MRSA and enterococci with high-level gentamicin resistance were the most common resistant organisms identified. No VRE were isolated; only 3% of 421 gram-negative isolates were considered resistant strains compared with 19% (P <.001) of gram-positive isolates. In the prospective study, 17% of 92 residents were found to have a resistant organism in 1 or more surveillance cultures; the most common resistant organisms were MRSA and high-level gentamicin-resistant enterococci. Only 1 resident was found to have VRE in a rectal swab culture; resistant gram-negative bacilli also were uncommon. CONCLUSIONS: Among residents of community LTCFs admitted to an AGS, resistant organisms were identified infrequently (<20% of admissions). MRSA was the most common resistant organism; VRE and resistant gram-negative bacilli were rare. These findings vary from other studies suggesting that there may be geographic variation in the epidemiology of resistant organisms among residents of community LTCFs.     

Prevalence and antimicrobial susceptibility of respiratory pathogens in patients with cystic fibrosis

Respiratory infection is very common in patients suffering from cystic fibrosis (CF). However, the antimicrobial resistance rate of isolates from CF patients is not often documented. In this study, 279 respiratory specimens of 146 “patients” were prospectively collected from July to December 2006. Microbiological cultures and antimicrobial susceptibility tests of the most frequently isolated bacteria were performed. Sputum and oropharyngeal swabs were processed for culture. During the study period, 50% of the patients harbored Staphylococcus aureus, 35% Pseudomonas aeruginosa, 4.7% Haemophilus influenzae. Methicillin resistant S. aureus (MRSA) were detected in 8 (6%) patients; ESBL and MBL-producing P. aeruginosa were not identified in these patients. The detection of MRSA in CF patients confirms that antimicrobial resistance patterns should be always kept under surveillance. Moreover, hygiene regulations in CF clinics should prevent a further spread of resistant bacterial strains.