The impact of healthcare-associated infections on patient care and the role of diagnostic molecular technology in infection prevention and control practice

Healthcare-associated infections (HCAIs) are a public health challenge in Ireland and pose a patient safety risk. The emergence of multi-drug resistant (MDR) Grampositive organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), Panton-Valentine leucocidin toxin-positive S. aureus (PVL-SA), and Gram-negative organisms, such as extended-spectrum betalactamase (ESBL)-producers and carbapenemase-producing Enterobacteriaceae (CPE), have made HCAIs more complex and diverse. Clinical microbiologists are an integral part of a hospital infection prevention and control (IPC) team, providing clinical guidance and expertise, assisting with the implementation of national and international IPC practices, managing outbreaks, and analysing rates of HCAIs. An efficient microbiology laboratory is an integral component of a hospital’s IPC strategy to facilitate the timely identification of pathogenic organisms from clinical specimens. In order to provide this service, a combination of skilled scientists who can perform traditional ‘bench’ tests and also utilise newer molecular diagnostics is required. Matrix-Assisted Laser Desorption/Ionisation Time of Flight Mass Spectrometry (MALDI-TOF MS) has facilitated the identification of bacteria, viruses and fungi in a convenient and time efficient manner and negated the need to employ older methodologies such as biochemical identification techniques. Faster identification of multi-drug resistant organisms (MDROs) is crucial for the timely management of HCAIs. Gradually, more laboratory work is becoming semi-automated and total laboratory automation (TLA) has become reality in many laboratories in Europe. To date, no Irish laboratory has installed a TLA system. Through greater public awareness of HCAIs, patients are more informed than ever regarding the risks associated with the acquisition of a HCAI and the concepts of patient safety and risk management have become key objectives for hospital management teams. As presented in this thesis, HCAIs have occurred in the Mid-West of Ireland across all age groups, despite the successful implementation of recommended IPC practices. Between 2009 and 2015, two outbreaks of CPE, an ESBL outbreak in a neonatal intensive care unit, the first reported case of neonatal mastitis secondary to PVL-SA, the first Irish outbreak of linezolid-resistant S. epidermidis and a rare case of daptomycin and vancomycin resistant enterococcal infective endocarditis have all occurred in the region. The Mid-West of Ireland currently has the highest national rates of CPE and higher than average national rates of ESBL-producing Escherichia coli in blood cultures. Future work to track the progression of these trends is needed. Infection prevention and control practices currently employed within the region are in line with national and international guidelines but despite this the rates of HCAIs remain problematic both clinically and practically, with regard to allocation of isolation facilities in acute hospitals. Leadership and support are required from hospital management to implement measures to reduce rates of HCAIs including providing funding for the purchase of laboratory equipment that can facilitate the rapid diagnosis of microorganisms, staff education and training including incentivising and rewarding wards to reduce rates of HCAIs, thoroughly investigating outbreaks as they occur and managing hospital beds in a safe and efficient manner. HCAIs have a negative impact on patient care and staff morale. A hospital-wide approach with input from all key stakeholders is needed for a sustained reduction in HCAI rates to be achieved

Surgical management of obesity: is bariatric surgery as good as it’s made out to be?

Objectives: Estimates from the WHO indicate that the prevalence of obesity in the developed world is reaching epidemic proportions. In 2005 there were at least 400 million obese adults worldwide and this figure is predicted to rise to 700 million by 2015, with an additional 2.3 billion overweight adults. This review aims to examine evidence for the benefits and risks of bariatric surgery and whether this treatment achieves both long-term weight loss and alleviation of obesity-related diseases. Methods: An electronic PubMed (1980-2008) search using MeSH database search terms ‘obesity or overweight’ and ‘bariatric surgery’ was performed. The search continued up to August 24, 2008, and yielded 388 papers, of which 62 were considered eligible for inclusion. Manual reference checks of papers cited in recent review articles were examined for suitable studies and the Cochrane Library database was also searched. Results: Bariatric surgery using restrictive and malabsorptive procedures achieves long-term significant weight loss compared with medical treatment, resulting on average in a 25-44kg weight loss at up to two years, and a 20kg loss up to eight years later. Cardiovascular, respiratory and psychological complications of obesity are also improved after bariatric surgery, with almost complete resolution of type 2 diabetes. Operative death rates are 1% and complication rates are acceptably low. Conclusions: There is strong evidence supporting a role for bariatric surgery in the management of obesity.</p

Against the onslaught of endemic KPC, the war is being lost on the Irish Front.

In the context of the excellent report of successful control of an outbreak of carbapenemase-producing Klebsiella pneumoniae in an Italian neonatal intensive care unit published in this journal (1), we wish to report the consequences of the first outbreak of KPC-producing Kliebsiella in Ireland and how, despite identification of operational factors associated with the incidence and best efforts towards rectifying those, our 410-bed hospital in the West of Ireland is failing to control endemic KPCs. Globally, there is recognition of the significant morbidity and mortality implications associated with emergence of carbapenemase-producing bacteria (2). The resulting vigilance has resulted in enhanced reporting of outbreaks, many being the first of their kind in specific countries (3), and descriptions of molecular studies to determine incidence and transfer of the carbapenemase-encoding blaKPC-harboring IncFIA plasmid between clonal variants (4). With indicative rates of carriage being circa 20%, infection control specialists are reacting with novel techniques for microbiological detection, strategies for prevention of nosocomial transmission, and clinical microbiologists are facing therapeutic challenges related to limited, relatively unproven antimicrobial treatment options

Limerick: forever associated with five lines of rhyme or infamous for irrepressible carbapenemase-producing enterobacteriaceae for all time?

Letter to Edito

Colonisation with extended-spectrum beta-lactamase (ESBL) not detected in a prevalence study.

Background The Mid-West of Ireland has higher than average national rates of invasive extended-spectrum beta-lactamase (ESBL) bloodstream infections and carbapenemase-producing Enterobacteriaceae (CPE), with increasing numbers of ESBL isolates detected in community-dwelling patients. Aims To conduct a point prevalence study in a convenience sample of the Mid-West population with the aim of determining the extent of ESBL colonisation Methods Utilising anonymised community stool samples that had completed routine analysis, we conducted a point prevalence study over a four-week period on all samples that met defined inclusion and exclusion criteria. Limited epidemiological data was recorded: (1) age of patient, (2) gender, (3) sender location. From these stool specimens, rectal swabs were inoculated (eSwab™ 480CE, Copan, Italy), which were subsequently cultured on selective chromogenic agar (Colorex™ ESBL). Culture plates were incubated aerobically at 37˚C for 24 hours. Results Of 195 samples processed, 58% (n=112) were from females. The median patient age was 62.4 years (range 20-94 years). 186 samples (95%) originated from general practitioner clinics. During the study period, only nine eligible stool samples were received from LTCF (6 public). From 195 Colorex™ ESBL chromogenic agar plates cultured, no ESBL-producing organisms were detected. Conclusions This community point prevalence study did not identify ESBL-colonisation despite high numbers of patients with invasive ESBL bloodstream infections presenting for admission in our institution. We believe this may be because of our small sample size. Data regarding antimicrobial exposure and other risk factors for ESBL-colonisation was also not available. We remain vigilant for ESBL-producing organisms

A case of fatal daptomycin-resistant, vancomycinresistantenterococcal infective endocarditis in end-stage kidney disease

Introduction: Ireland currently has the highest reported rate in Europe of vancomycin-resistant Enterococcus (VRE) isolated from the bloodstream, but data regarding the prevalence of VRE endocarditis remain scarce. Treatment options for Enterococcus-mediated endocarditis are limited, and therefore daptomycin is commonly used off licence in this setting. Case presentation: A 60-year-old male with end-stage kidney disease (ESKD) presented with VRE bacteraemia secondary to a gangrenous right foot colonized with vancomycin-resistant Enterococcus faecium. Aortic valve endocarditis was confirmed using transoesophageal echocardiography. Treatment was commenced with linezolid and subsequently modified to combination therapy with daptomycin and rifampicin. High-dose daptomycin therapy was employed unsuccessfully and, after 20 days of therapy, daptomycin resistance emerged, which proved fatal. Conclusion: The case was ethically challenging and involved a refusal of amputation and, ultimately, any form of treatment by the patient. In summary, however, daptomycin-resistant VRE bacteraemia complicated by recalcitrant daptomycin-resistant VRE endocarditis proved fatal for this patient. Further evaluation of the efficacy and safety of high-dose daptomycin for the treatment of VRE infective endocarditis is needed

An optimised work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs

Rapid detection of patients with carbapenem-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilising existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n=10) and anonymised community stool specimens (n=200). Rectal swabs (eSwab™) were inoculated from collected stool specimens and a manual DNA extraction method (QIAamp® DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPE® assay. The three step process of making the eSwab™, extracting DNA manually and running the Check-Direct CPE® assay, took <5 minutes, 1 hour 30 minutes and 1 hour 50 minutes, respectively. It was time efficient with a result available in under 4 hours, comparing favourably with the existing method of CPE screening; average time-to-diagnosis of 48/72 hours. Utilising this CPE work-flow would allow a ‘same-day’ result. Antimicrobial susceptibility testing results, as is current practice, would remain a ‘next-day’ result. In conclusion, the Check-Direct CPE® assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing

Panton-Valentine leucocidin toxin-positive staphylococcus aureus-mediated neonatal mastitis.

no abstract availabl

Combined education and skin antisepsis intervention for persistently high blood-culture contamination rates in neonatal intensive care

Contaminated blood cultures represent challenges regarding diagnosis, duration of hospitalization, antimicrobial use, pharmacy and laboratory costs. Facing problematic neonatal blood culture contamination (3.8%), we instigated a successful intervention combining skin antisepsis using sterile applicators with 2% chlorhexidine gluconate in 70% isopropanol prior to phlebotomy (replacing 70% isopropanol) and staff education. In the six months prior to intervention, 364 neonatal peripheral blood samples were collected. Fourteen (3.8%) were contaminated. In the post-intervention six months, 314 samples were collected. Three (0.96%) were contaminated, representing significant improvement (Fisher’s exact test: P= 0.0259). No dermatological sequelae were observed. The improvement has been sustained

A case of Panton–Valentine leucocidin toxin-positive staphylococcus aureus-mediated neonatal mastitis

Introduction: Neonatal mastitis is an inflammatory condition of the breast frequently associated with Staphylococcus aureus. While Panton–Valentine leucocidin (PVL), a B-pore-forming cytotoxin, is commonly associated with enhanced virulence in community-acquired methicillinresistant S. aureus isolates, this is the first report to our knowledge of neonatal mastitis caused by PVL-positive S. aureus. Case presentation: A 20-day-old full-term female neonate presented with bilateral mastitis, complicated by bilateral abscess formation. PVL toxin-positive S. aureus was cultured from aspirates of both breasts. All family members, none of whom presented with symptoms of infection, and, specifically, maternal vaginal samples proved negative for PVL-positive S. aureus. Successful resolution involved surgical drainage and clindamycin therapy. Conclusion: While PVL toxin-positive S. aureus has previously been implicated in bovine and ovine mastitis, there may now be a need for vigilance with respect to human incidence. Due to PVL-mediated tissue necrosis, breast abscess formation and poor response to conventional antimicrobial therapy should, perhaps, be a cause for suspicion of PVL-bearing S. aureus and expediting of appropriate therapy to avoid potential for long-term consequences such as abnormal breast development