Application Of Infection Control Measures Research Articles

Phenotypic and molecular characterization of antimicrobial resistance and virulence factors in Pseudomonas aeruginosa clinical isolates from Recife, State of Pernambuco, Brazil

The emergence of carbapenem resistance mechanisms in Pseudomonas aeruginosa has been outstanding due to the wide spectrum of antimicrobial degradation of these bacteria, reducing of therapeutic options. Sixty-one clinical strains of P. aeruginosa isolated from five public hospitals in Recife, Pernambuco, Brazil, were examined between 2006 and 2010, aiming of evaluating the profiles of virulence, resistance to antimicrobials, presence of metallo-β-lactamase (MBL) genes, and clonal relationship among isolates. A high percentage of virulence factors (34.4% mucoid colonies; 70.5% pyocyanin; 93.4% gelatinase positives; and 72.1% hemolysin positive) and a high percentage of antimicrobial resistance rates (4.9% pan-resistant and 54.1% multi-drug resistant isolates) were observed. Among the 29 isolates resistant to imipenem and/or ceftazidime, 44.8% (13/29) were MBL producers by phenotypic evaluation, and of these, 46.2% (6/13) were positive for the blaSPM-1 gene. The blaIMP and blaVIM genes were not detected. The molecular typing revealed 21 molecular profiles of which seven were detected in distinct hospitals and periods. Among the six positive blaSPM-1 isolates, three presented the same clonal profile and were from the same hospital, whereas the other three presented different clonal profiles. These results revealed that P. aeruginosa is able to accumulate different resistance and virulence factors, making the treatment of infections difficult. The identification of blaSPM-1 genes and the dissemination of clones in different hospitals, indicate the need for stricter application of infection control measures in hospitals in Recife, Brazil, aiming at reducing costs and damages caused by P. aeruginosa infections.

Herausforderungen durch Infektionen und mehrfach-resistente Bakterien bei alten Menschen in Heimen

Healthcare-associated infections not only affect patients in acute care hospitals but also patients in need of long-term care. As the elderly are generally most affected, the demographic change in Germany faces a range of increasing challenges in the field of infection control. The ageing process itself is accompanied by several physiological and pathological changes which may result in an increase in the risk of infectious diseases. Elderly living in long-term care facilities (LTCFs) may in addition be exposed to further risks due to their everyday life in a community, nursing care and the, to some extent, inappropriate use of antibiotics. Bacteria that have become resistant to commonly used antimicrobial agents are meanwhile prevalent in nursing homes. Caregivers often feel left alone when facing the task of achieving a balance between the need for a comfortable familiar environment and the application of infection control measures according to a resolute prevention strategy. This review aims to give an overview about the characteristics of infections among the elderly, especially with respect to long-term care.

HANDS: standardised intravascular practice based on evidence

Observed and audited variability in the insertion and care of vascular access devices (VADs), despite national guidance, led an intravascular (i.v.) team to develop seven basic standards under the mnemonic of HANDS. This initiative combined the Saving Lives guidance (Department of Health, 2007) with i.v. care bundles to reinforce best practice. The main reasons for the project were to decrease bacteraemia rates related to i.v. devices and to improve practice. The strategy of strengthening care bundling--Project HANDS--with a targeted education programme was adopted to ensure i.v. practice was consistent and evidence based. This project took a novel approach that evaluated the application of infection control measures, using i.v. device care as a tool to influence organisational change. This resulted in quality improvements and better patient outcomes. Further actions include disseminating the learning from this project to healthcare partners and in the community.

Viral hemorrhagic fevers: advancing the level of treatment

The management of viral hemorrhagic fevers (VHFs) has mainly focused on strict infection control measures, while standard clinical interventions that are provided to patients with other life-threatening conditions are rarely offered to patients with VHFs. Despite its complexity, a proper clinical case management of VHFs is neither futile nor is it lacking in scientific rationale. Given that patient outcomes improve when treatment is started as soon as possible, development and implementation of protocols to promptly identify and treat patients in the earliest phases of diseases are urgently needed. Different pharmacological options have been proposed to manage patients and, as for other life-threatening conditions, advanced life support has been proved effective to address multiorgan failure. In addition, high throughput screening of small molecular libraries has emerged as a novel promising way to find new candidates drugs for VHFs therapy and a relevant number of new molecules are currently under investigation. Here we discuss the current knowledge about VHF clinical management to propose a way to step up the approach to VHFs beyond the mere application of infection control measures.

Linezolid-Resistant Enterococci in Greece: Epidemiological Characteristics

Background: 14 linezolid-resistant enterococci (6 Enterococcus faecium and 8 Enterococcus faecalis) collected during 2009 from patients hospitalized in intensive care units of different Greek hospitals were investigated. Methods: The mechanism of resistance to linezolid was determined by sequencing analysis of the domain V of 23S rDNA, while the clonal relatedness was defined by pulsed-field gel electrophoresis and multilocus sequence typing. Results: All linezolid-resistant enterococci carried the G2576T mutation. E. faecium belonged to the international epidemic clones ST16, ST17, ST203 and ST65, while all E. faecalis strains belonged to the ST28 clone. Conclusions: The spread of common linezolid-resistant enterococcal clones in intensive care units located in different areas of Greece emphasizes the importance of application of infection control measures to prevent the spread of such strains.

Multidrug-resistant Gram-negative bacteria: how to treat and for how long

The emergence of multidrug-resistant (MDR) Gram-negative bacilli creates a big problem for the treatment of nosocomial infections. As the pharmaceutical pipeline wanes, the only therapeutic options are two revived antibacterials (colistin and fosfomycin), a newer one (tigecycline) and an early-phase neoglycoside (ACHN-490). Polymyxins, known since 1947, are mostly represented by polymyxin E (colistin), which has recently gained a principal position in the management of the most difficult-to-treat MDR Gram-negative pathogens – Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. However, despite promising therapeutic results in 59–75% of cases, the reported studies share common drawbacks, i.e. the absence of a control group, their retrospective nature, variable dosing and duration of therapy, simultaneous administration of other antibiotics in >70% and a lack of resistance development monitoring. The necessity for well-designed prospective clinical trials is therefore urgent. Fosfomycin is active in vitro against MDR Enterobacteriaceae, including a high proportion of P. aeruginosa; however, clinical experience is lacking with the parenteral formulation in MDR infection and on the best combinations to prevent resistance development. Tigecycline, which is active against MDR Enterobacteriaceae and A. baumannii, has shown satisfactory clinical experience. However, dosage adjustment is required because of low blood levels. ACHN-490, which has promising in vitro activity against MDR K. pneumoniae, is still in early phase II trials in urinary tract infections. Meanwhile, the strict application of infection control measures is the cornerstone of nosocomial infection prevention, and antibiotic stewardship, exemplified by appropriate duration of therapy and de-escalation policies, should not be overlooked.

Potential for nosocomial transmission of multidrug-resistant (MDR) tuberculosis in a South African tertiary hospital

Tuberculosis (TB) is a major health problem in the Western Cape, with an incidence exceeding 900 per 100 000 people. Nosocomial transmission of TB, and particularly drug-resistant TB, is a potential risk that may be undetected. Rapid diagnosis and rapid institution of effective anti-TB treatment, combined with appropriate infection control measures, are essential to prevent nosocomial transmission of TB. To estimate the potential for nosocomial transmission, we aimed to determine the in-hospital delays in diagnosis and treatment of patients with multidrug-resistant (MDR)-TB at a tertiary care hospital. A descriptive study, based on retrospective review of patient records and laboratory data, including all adult patients (>13 years) where TB culture and susceptibility testing confirmed MDR- TB on specimens submitted to Tygerberg Hospital's National Health Laboratory Service (NHLS) laboratory in 2007. Thirty-one patients with MDR-TB were identified. The median laboratory turnaround time (TAT) from collection of specimen to confirmation of MDR-TB was 40 days, while the median time from the time of first presentation at Tygerberg Hospital to institution of MDR treatment was 44 days. Twenty patients were considered infectious during their hospital stay, generating 345 inpatient infectious days. The study suggests that there is an ongoing substantial risk for nosocomial transmission of MDR-TB at Tygerberg Hospital. We propose improvements, including the use of rapid drug susceptibility testing. The consistent application of infection control measures to prevent nosocomial spread of TB, including MDR-TB, remains vital.

Changes in laboratory and clinical workload for Clostridium difficile infection from 2003 to 2007 in hospitals in Edinburgh

AbstractClostridium difficile infection (CDI) is a growing concern with regard to increases in incidence and its associated financial burden. A retrospective analysis of patients admitted to Hospitals in Edinburgh from 2003 to 2007 and tested for C. difficile toxins was performed. A total of 45 412 faecal samples were tested and 6286 (13.8%) were positive. Overall CDI was identified in 1.7 cases/1000 in-patient occupied bed days (OBD). The incidence of CDI fell from 1.98 cases/1000 OBD in 2006 to 1.48 cases/1000 OBD in 2007. Renal Medicine, including Transplant Surgery, and Intensive Care had the highest incidence, with >6.2 cases/1000 OBD each, followed by Infectious Diseases and Gastrointestinal Medicine, with rates of 5.5 and 4.42 cases/1000 OBD, respectively. Medicine of the Elderly had an incidence of 1.69 cases/1000 OBD. Incidence increased with age, from 0.45 cases/1000 OBD in the 0–20-year-old age group to 2.02 cases/1000 OBD in the 61–80-year-old age group. Twelve percent of all toxin-positive patients were transferred through a minimum of two specialties when they remained positive for C. difficile toxins. Estimated costs over the study period for toxin testing were approximately £126 500 and the minimal potential hospitalization costs for patients with CDI was £20 000 000. The overall incidence of patients identified with CDI fell in 2007 compared to 2006. The incidence has increased with age; however, patients in Medicine of the Elderly had a much lower incidence than in several other specialties and therefore risk assessment of CDI should also be targeted within other specialties. Judicious application of infection control measures remains important for preventing CDI.

Operating room health team knowledge and performance regarcing the application of infection control measures: A suggested policy

Operating room health team knowledge and performance regarcing the application of infection control measures: A suggested policy

Staphylococcus aureus Bacteremia in Older Adults: Predictors of 7-Day Mortality and Infection With a Methicillin-Resistant Strain

To determine the predictors of 7-day mortality in older adult patients with Staphylococcus aureus bacteremia after controlling for comorbidity using the Charlson weighted index of comorbidity (WIC) and to identify the risk factors associated with bacteremia due to methicillin-resistant S. aureus (MRSA). Retrospective cohort study from January 2003 until December 2004. Two tertiary care, university-affiliated hospitals. One hundred thirty-five hospitalized patients with S. aureus bacteremia were included in the study. All patients who were 60 years or older and had 1 or more blood cultures positive for S. aureus were included in the study. The primary outcome was death 7 days after the onset of S. aureus bacteremia. Twenty-one patients (15.6%) died within 7 days after the onset of S. aureus bacteremia. Seventy-four patients (56.1%) had MRSA bacteremia. Multivariate analysis identified 3 independent determinants of 7-day mortality: Charlson WIC score greater than 5 (odds ratio [OR], 3.6 [95% confidence interval {CI}, 1.1-11.2]; P=.03), previous hospitalization in the past 3 months (OR, 5.0 [95% CI, 1.1-25.1]; P=.04), and altered mental status at the onset of S. aureus bacteremia (OR, 13.6 [95% CI, 2.9-64.6]; P=.001). Multivariate analysis identified previous hospitalization in the past 3 months (OR, 2.6 [95% CI, 1.1-5.9]; P=.02), residence in a long-term care facility (OR, 4.5 [95% CI, 1.7-12.3]; P=.003), and altered mental status at the onset of S. aureus bacteremia (OR, 2.5 [95% CI, 1.5-5.6]; P=.02) to be independently associated with the presence of MRSA. The Charlson WIC is significantly associated with increased mortality of S. aureus bacteremia in older adults. Previous hospitalization in the past 3 months, residence in a long-term care facility, and altered mental status should be used as a guidance for empirical vancomycin therapy and application of infection control measures in older adults with suspected S. aureus bacteremia.

β‐lactam antibiotic resistance in aerobic commensal fecal flora of newborns

The purpose of the present paper was to prospectively determine the rate of beta-lactam antibiotic resistance in commensal fecal flora of newborns and the risk factors leading to this colonization. One hundred and eighteen newborns in the neonatal intensive care unit (NICU) group (n = 38), the neonatal ward group (n = 36), and the control group (n = 44) were enrolled. Three or four stool samples were obtained from each infant, 15 days apart. Bacterial growth in Eozin Methylene Blue (EMB) agar + 10 microg ampicillin/mL was considered to be ampicillin-resistant bacteria, and antibiotic susceptibility and extended spectrum beta-lactamases (ESBL) production was investigated in those bacteria. Colonization with ampicillin-resistant commensal fecal flora microorganisms was determined in 75.2% of 367 stool samples. Klebsiella spp. and Escherichia coli were identified in 59% and 41% of the samples, respectively. The lowest rate of ampicillin-resistant bacterial colonization was determined in the NICU group. Microorganisms producing ESBL were identified in 33.7% of 367 stool samples. Fifty-one and 73 of ampicillin-resistant E. coli and Klebsiella spp. isolates were determined to produce ESBL, respectively. There was no difference with respect to colonization with ESBL-producing microorganisms between the three groups. When risk factors related to colonization with ESBL-producing microorganisms in stool samples were evaluated through the whole study period, very low birthweight, vaginal delivery, infant antibiotic usage, maternal antibiotic usage, male sex and premature rupture of membranes were determined as risk factors, while feeding with nasogastric tube was identified as a protective factor. When the risk factors related to colonization with ESBL-producing bacteria in stool samples after discharge from the hospital were evaluated, failure to feed breast milk was determined as the only risk factor. To decrease mortality and morbidity due to infection caused by resistant microorganisms colonized in the intestine flora of the infant, protection of normal non-pathogenic bacterial colonization is important. This can be provided by feeding neonates with breast milk, application of infection control measures efficiently, and limitation of antibiotic usage only to strict clinical indications.

Persistence of a clone of glycopeptide-resistant Enterococcus faecalis among patients in an intensive care unit of a Greek hospital.

To investigate an outbreak of glycopeptide-resistant Enterococcus faecalis (GREF) in the intensive care unit (ICU) of 'G. Gennimatas' General Hospital, Athens, Greece. Between August 2000 and November 2001, 20 highly GREF isolates were recovered from severe infections of separate patients in the ICU. The isolates were tested by PCR, PFGE, mating experiments and plasmid analysis. All isolates carried the vanA gene. Nineteen isolates fitted to one clone by macrorestriction analysis with four subclones being consecutively detected. Each subclone seemed to predominate for a specific time period. Additionally, four GREF isolates related to the ICU clone were recovered from other wards of the hospital. Our findings indicate that a monoclonal GREF outbreak persisted for more than 1 year in a large Greek hospital. The rate of GREF isolation declined after the application of infection control measures.

High Rate of Oxacillin-ResistantStaphylococcus aureusIsolates in an Italian University Hospital

We reviewed our routine clinical laboratory records from January 1990 to March 1993 to evaluate the rate of oxacillin-resistance among nosocomial isolates of Staphylococcus aureus. Of 265 clinically significant isolates, 174 (65%) were oxacillin-resistant S. aureus (ORSA). Most of these strains were obtained from surgery patients and/or were isolated from surgical wounds. The isolations of S. aureus increased during the study period: 45 in 1990, 50 in 1991, 130 in 1992 and 40 in the first trimester of 1993. The annual rates of ORSA among S. aureus isolated varied from 62 to 68% through these years. Most ORSA isolates proved resistant to ciprofloxacin, gentamicin and rifampicin, and susceptible to vancomycin, netilmicin and cotrimoxazole. Based on these results, the need for a stringent application of infection control measures is outlined.

Control of Colonization and Transmission of Pathogenic Bacteria in the Hospital

A hospital is a milieu conducive to the development and spread of infection. Patients' own flora, microorganisms in the hospital environment or those carried by medical personnel, intrinsically contaminated commercial products, and infected patients are major reservoirs of nosocomial pathogens. Use of invasive devices greatly amplifies transmission, colonization, and susceptibility to infection. Staphylococcus aureus infections are caused by autochthonous strains or exposure to medical personnel who are carriers; infections with gram-negative bacilli are endogenously acquired or derive from contact with contaminated aqueous sources within the hospital. Carriage of microorganisms on the hands of noncolonized medical personnel appears to be a major mode of cross-infection. Research is needed to better define the epidemiology of endemic nosocomial infections in order to develop more effective control measures, to evaluate more widely the efficacy of protective isolation, and to improve the safety of devices. More consistent application of infection control measures would have considerable immediate benefit.