Biofilm formation by bacteria isolated from intensive care units of a tertiary care hospital, with special relevance to its risk factors

Background: The purpose of this study was to detect biofilm formation by bacterial isolates from patients with device associated infection admitted in intensive care units (ICUs), to compare the three methods used for detection of bioiflm, to compare the antimicrobial susceptibility pattern of the biofilm producers with the non-producers and to study the risk factors associated with biofilm formation.Methods: A total of 115 bacterial isolates from patients with device associated infection admitted in different ICU for a period of one year was included in the study. These clinical isolates were detected for biofilm formation by tissue culture plate method, tube method and Congo red agar method. Kirby-Bauer disc diffusion method of antibiotic susceptibility was performed on all isolates.Results: Out of the 115 bacterial isolates, 71 were biofilm producers. Tissue culture plate method detected the maximum number of biofilm producers (61.7%). The maximum number of biofilm producers were isolated from tracheal aspirate and endotracheal tubes (52.1%) followed by blood (17%) and urine (12.6%) respectively. The predominant biofilm producing isolates were Klebsiella pneumoniae (39.4%), Staphylococcus aureus (19.7%) and Pseudomonas aeruginosa (16.9%). Multi drug resistance among the biofilm producers was significantly higher than the non-biofilm producers (p value=0.0125). The risk of biofilm formation was seen to increase with the increase in duration of hospital stay (p value=0.0092, statistically very significant).Conclusions: From this study it was found that a high degree of biofilm producers were isolated from patients on indwelling devices. Tissue culture plate was found to be the most accurate method. The degree of multidrug resistance among the bioiflm producers was significantly higher than the non-producers.

BIOFILM PRODUCTION AND ANTIMICROBIAL RESISTANCE IN VENTILATOR ASSOCIATED PNEUMONIA (VAP) PATHOGENS OF ICUs OF TERTIARY CARE CENTER OF CENTRAL GUJARAT.

Background: In critical care units, Ventilator-associated pneumonia (VAP) is a common device-associated infection in mechanically ventilated patients. Problem gets worst of associated with biofilm producing organism with higher antimicrobial resistance. The current study was carried out to observe the pattern of antimicrobial resistance, biofilm forming capacity of isolates causing Ventilator-associated pneumonia and other risk factors associated with VAP patients in intensive care units of Shree Krishna Hospital, Karamsad. Methodology: 97 total tracheal aspirate culture isolates recovered from 83 mechanically ventilated patients diagnosed to be suffering from VAP as per NHSN definition, admitted in various ICUs of Shree Krishna Hospital, Karamsad during the study duration were included in the study. Relevant clinical history of the patients and other details taken for various patient variable factors like age, gender, co-morbid conditions, indoor days, ventilator days, final patient outcome and other lab based investigations done as indicator of active pneumonia or sepsis from the electronic hospital database available on hospital information system. The tracheal aspirate culture isolates were then tested for antimicrobial susceptibility testing by Vitek2compact and in-vitro biofilm production assay using microtitre plate method. Objective of the present study was to determine the incidence of antimicrobial resistance, biofilm forming capacity of VAP pathogens, to determine risk factors associated and final outcome in VAP patients infected with biofilm forming pathogens. Chi-square test was used to check the relation between the categorical variables while t test was applied in case of continuous variables. A p value less than 0.05 was considered as statistically significant. Results: Out of total 83 patients of VAP, 97 isolates recovered in tracheal aspirate culture. Out of total 83 patients, 42 patients (49 isolates) were found Biofilm producer (BFP) and 41 patients (48 isolates) were found Biofilm non-producer (BFNP). Out of 97 culture total isolates, the most common organisms grew were Klebsiella pneumoniae (29 isolates), Acinetobacter baumani (28 isolates) and Pseudomonas aeruginosa (19 isolates) apart from them lesser number of isolates of Staphylococcus aureus (6), Escherichia coli (5), Pantoea spp. (2), Serretia marcescens (2), Pseudomonas putida (1), Sphingomonas paucimobilis (1), Stenotrophomonas maltophila (1), Enterococcus faecium (1), Candida famata (1) and Candida tropicalis (1). The antimicrobial resistance was compared in three major pathogen between BFP and BFNP isolates, i.e. Klebsiella pneumoniae, Acinetobacter baumani and Pseudomonas aeruginosa, which was found to be statistically insignificant. Mortality was recorded higher in BFP patients (16.67%) compared to BFNP patients (7.3%) of VAP, but statistically it was not found to be significant (p value > 0.05). Conclusions: Incidence of BFP and BFNP associated VAP seen 50.51% and 49.49% respectively out of total 97 isolates. Biofilm forming pathogen causing VAP may not influence the outcome of the patient but, biofilm producer pathogens continue to be associated with pathogens causing VAP in significant amount of total cases. Typical hospital acquired strains like Klebsiella pneumoniae, Acinetobacter baumani and Pseudomonas aeruginosa is recorded frequently compared to other pathogens. Key words: Intensive Care Unit, anti-microbial resistance, VAP, Bio film, Health care associated infection, Indwelling device associated infection.

Bacterial virulence plays a crucial role in MRSA sepsis

Bacterial sepsis is a major global cause of death. However, the pathophysiology of sepsis has remained poorly understood. In industrialized nations, Staphylococcus aureus represents the pathogen most commonly associated with mortality due to sepsis. Because of the alarming spread of antibiotic resistance, anti-virulence strategies are often proposed to treat staphylococcal sepsis. However, we do not yet completely understand if and how bacterial virulence contributes to sepsis, which is vital for a thorough assessment of such strategies. We here examined the role of virulence and quorum-sensing regulation in mouse and rabbit models of sepsis caused by methicillin-resistant S. aureus (MRSA). We determined that leukopenia was a predictor of disease outcome during an early critical stage of sepsis. Furthermore, in device-associated infection as the most frequent type of staphylococcal blood infection, quorum-sensing deficiency resulted in significantly higher mortality. Our findings give important guidance regarding anti-virulence drug development strategies for the treatment of staphylococcal sepsis. Moreover, they considerably add to our understanding of how bacterial sepsis develops by revealing a critical early stage of infection during which the battle between bacteria and leukocytes determines sepsis outcome. While sepsis has traditionally been attributed mainly to host factors, our study highlights a key role of the invading pathogen and its virulence mechanisms.

Suspected infection following pacemaker implantation: a case study

Infection is a serious complication of pacemaker systems. This case study discusses the management of a patient who presented with a suspected pacemaker-related infection. The use of a consultation model ensured a holistic approach to patient assessment and underpinned the prescribing decisions. Focus is given to the pharmacological management of device-associated infection and the drug therapy flucloxacillin. Relevant evidence and guidelines are referred to as support for treatment decisions and a collaborative patient approach is demonstrated to help achieve the best health outcome.

Differences in Device-Associated Infections Rates in Argentina

Background: Infection control programs (ICPs) are essential to reducing, in a progressive and sustained manner, healthcare-associated infections (HAIs). To achieve this goal these programs need not only resources (ie, trained human resources and financial resources) but also institutional leadership support. In our country, epidemiological surveillance is voluntary and is registered in the Argentina National Hospital Infection Surveillance System (VIHDA) where 114 hospitals and 78 adult intensive care unit (ICU) report their HAI rates. Many of these institutions do not have IPC or specific resources for this purpose. On the other hand, there are institutions with IPC, recognized by an international accreditation like Joint Commission International, that carry out an advanced and continuous program, with specific improvement goals for prevention and infection control. There is an imperative need in low- and middle-income countries to highlight the impact of ICPs in this setting and to promote regulations for mandatory surveillance and ICPs in all acute-care hospitals. Objective: To compare the rates for device-associated infections in ICUs of institutions with advanced ICPs versus national rates. Design: We conducted an observational, retrospective study, which includes device associated infection rates in adult critical care units from 2014 to 2018. We included all ICUs reporting to VIHDA and 3 surgical-medical teaching hospitals with an advanced ICP and Joint Commission International accreditation (Hospital Italiano de Buenos Aires, Hospital Universitario Austral, Hospital Aleman). The VIHDA definition was used to define central line-associated bloodstream infection (CLABSI), catheter-related urinary infection (CAUTI), and ventilator-associated pneumonia (VAP). The rates were compared as adjusted reasons for exposure time using openepi.com software provided by the CDC. Results: Device associated infection rates in hospitals with advanced ICPs and in hospitals in the national surveillance system in Argentina are shown in Table 1. Compliance with infection control measures and bundles for device-associated infections in the 3 hospitals with advanced ICPs was >80%. No data were available for the rest of hospitals included the national surveillance system. Conclusions: Lower infection-control rates, catheter-related bloodstream infection and VAP, are possible in a middle-income country like Argentina when resources are allocated for this purpose and hospital leadership reinforces the efforts. Notably, all 3 hospitals improved their rates over time. The differences in catheter-related bloodstream infection and VAP rates between these hospitals and the rest of the hospitals in our surveillance system was significant and highlights the need for support when it comes to implementing ICPs.Funding: NoneDisclosures: Wanda Cornistein reports fees for conferences not related to this topic from the following speaker’s bureaus: Pfizer, Merck, and Becton Dickinson.

Recurrent pump thrombosis is common after axial continuous-flow left ventricular assist device exchange

In selected patients with left ventricular assist device–associated infection or malfunction, pump exchange may become necessary after conservative treatment options fail and heart transplantation is not readily available. We examined the survival and complication rate in patients (⩾19 years of age) who underwent HeartMate II to HeartMate II exchange at our institution from 1 January 2010 to 28 February 2018. Clinical outcomes were analyzed and compared for patients who underwent exchange for pump thrombosis (14 patients), breach of driveline integrity (5 patients), and device-associated infection (2 patients). There were no differences in 30-day mortality (p = 0.58), need for temporary renal replacement therapy (p = 0.58), right ventricular mechanical support (p = 0.11), and postoperative stroke (p = 0.80) among groups. Survival at 1 year was 90% ± 7% for the whole cohort and 85% ± 10% for those who underwent exchange for pump thrombosis. In patients exchanged for device thrombosis, freedom from re-thrombosis and survival free from pump re-thrombosis at 1 year were 49% ± 16% and 42% ± 15%, respectively. No association of demographic and clinical variables with the risk of recurrent pump thrombosis after the first exchange was identified. Survival after left ventricular assist device exchange compares well with published results after primary left ventricular assist device implantation. However, recurrence of thrombosis was common among patients who required a left ventricular assist device exchange due to pump thrombosis. In this sub-group, consideration should be given to alternative strategies to improve the outcomes.