Bloodstream Infections In Hospitals Research Articles

Evaluation of antibiotic resistance, toxin-antitoxin systems, virulence factors, biofilm-forming strength and genetic linkage of Escherichia coli strains isolated from bloodstream infections of leukemia patients

BackgroundOne of the most common complications in patients with febrile neutropenia, lymphoma, leukemia, and multiple myeloma is a bloodstream infection (BSI).ObjectiveThis study aimed to evaluate the antibiotic resistance patterns, virulence factors, biofilm-forming strength, and genetic linkage of Escherichia coli strains isolated from bloodstream infections (BSIs) of leukemia patients.MethodsThe study conducted in Iran from June 2021 to December 2022, isolated 67 E. coli strains from leukemia patients’ bloodstream infections in hospitals in two different areas. Several techniques including disk diffusion and broth microdilution were used to identify patterns of antibiotic resistance, microtiter plate assay to measure biofilm formation, and PCR to evaluate the prevalence of different genes such as virulence factors, toxin-antitoxin systems, resistance to β-lactams and fluoroquinolone antibiotics of E. coli strains. Additionally, the genetic linkage of the isolates was analyzed using the Enterobacterial Repeat Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) method.ResultsThe results showed that higher frequency of BSI caused by E. coli in man than female patients, and patients with acute leukemia had a higher frequency of BSI. Ampicillin and Amoxicillin-clavulanic acid showed the highest resistance, while Imipenem was identified as a suitable antibiotic for treating BSIs by E. coli. Multidrug-resistant (MDR) phenotypes were present in 22% of the isolates, while 53% of the isolates were ESBL-producing with the blaCTX-M gene as the most frequent β-lactamase gene. The fluoroquinolone resistance genes qnrB and qnrS were present in 50% and 28% of the isolates, respectively. More than 80% of the isolates showed the ability to form biofilms. The traT gene was more frequent than other virulence genes. The toxin-antitoxin system genes (mazF, ccdAB, and relB) showed a comparable frequency. The genetic diversity was detected in E. coli isolates.ConclusionOur results demonstrate that highly diverse, resistant and pathogenic E. coli clones are circulating among leukemia patients in Iranian hospitals. More attention should be paid to the treatment and management of E. coli bloodstream infections in patients with leukemia.

Changes in the incidence of Candida-related central line-associated bloodstream infections in pediatric intensive care unit: Could central line bundle have a role?

Candida species are among the most prevalent microorganisms in pediatric critical care units that cause central line-associated bloodstream infections . The goal of this study was to assess the therapeutic benefit of central line bundle for the prevention of Candida species-related bloodstream infections in pediatric intensive care units. The study covered the period from January 1, 2009, to December 31, 2019. Pre-bundle and bundle phases were included in the research. The Clinical Microbiology Laboratory's records revealed episodes of Candida-related central line-associated bloodstream infections. The study was conducted in the Dr. Behçet Uz Child Disease and Pediatric Surgery Training and Research Hospital's PICU (which has 24 beds and admits 350 patients per year). This study included pediatric patients in the pediatric intensive care unit with non-tunneled central venous catheters . In the pediatric intensive care unit, a central line bundle was started. A total of 236 Candida-related central line-associated bloodstream infections were discovered during the study period. Non-albicans Candida accounted for 83.5% (197) of the total, whereas C.albicans accounted for 16.5%(39). During the pre-bundle period, 137 Candida species were isolated from the patients, while 99 Candida species were isolated during the bundle period. Candida-related central line-associated bloodstream infections dropped from 13.68 to 5.93 per 1000 CL-days after the central line bundle was used ( p < 0.001). According to our findings, the central line bundle greatly reduced central line-associated Candida species bloodstream infections. Central line bundles are an effective scientific solution for preventing Candida-related central line-associated bloodstream infections in hospitals with high Candida prevalence.

Antimicrobial Resistance of Enterobacteriaceae in Bloodstream Infections in Hospitalized Patients in Southern Poland

Aim: The aim of this study was to highlight antimicrobial resistance among Enterobacteriaceae isolated from bloodstream infections in hospitals in southern Poland. Materials and Methods: The present study includes laboratory-confirmed secondary bloodstream infections (LC-BSIs), in the years 2015–2018, in hospitalized adult patients (≥18). Episodes of BSIs were defined according to the strictly described guidelines. Antimicrobial susceptibility testing was performed with the automated system and the disc diffusion method. Extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriaceae were detected using the double-disc synergy test. Results: Between 2015 and 2018, 356 episodes of secondary BSIs in 997 patients aged 21–96 years were documented in a prospective study, including 134 (37.6%) ESBL-producing Enterobacteriaceae. Escherichia coli was the predominant pathogen in internal medicine (37.6%) and surgery units (46.8%); in intensive care units (ICUs), Klebsiella pneumoniae was isolated more frequently (33.3%). Enterobacteriaceae were highly resistant to most antimicrobial agents. K. pneumoniae isolates had a higher level of resistance than E. coli, regardless of the unit. Conclusions: The increase in AMR and the widespread distribution of ESBL-producing Enterobacteriaceae in Polish hospitals can be related to the lack of or inappropriate antibiotic treatment.

Management of home parenteral nutrition catheter-related bloodstream infections in hospitals outside of a specialized intestinal failure center.

Catheter-related bloodstream infections (CRBSIs) remain the commonest complication associated with home parenteral nutrition (HPN). Although the management outcomes of CRBSIs have been extensively reported by specialized intestinal failure (IF) centers, there are minimal data reporting CRBSI outcomes for HPN-dependent patients admitted to nonspecialized hospitals. This was an observational study from a prospectively maintained database of CRBSIs in HPN-dependent patients managed outside of a specialized IF center. Three hundred and six patients from a total cohort of 1066 HPN-dependent patients suffered from 489 CRBSI events from 2003 to 2021; after 2017, 71 of these events were managed at the patient's local, nonspecialized hospital and the remainder at the specialized IF center. From 2017 to 2021, salvage of the central venous catheter (CVC) with antimicrobial therapy was attempted in 32 out of 71 (45.1%) patients admitted to the nonspecialized hospital, with successful salvage recorded in 23 (71.8%) cases. Notably, CVC salvage was attempted more commonly (77 out of 103 [74.8%]; P = 0.004 vs nonspecialized hospital), with a better salvage success rate (64 out of 77 [83.1%] P = 0.01 vs nonspecialized hospital) in patients who were admitted to the specialized IF center. In some instances, CRBSIs can be effectively managed when patients presenting to a nonspecialized hospital; however, overall salvage is more likely to be successful in the specialized setting. Further development of clinical and educational networks between IF centers and patients' local hospitals aimed at standardizing care may lead to improved CRBSI outcomes.

Trends in Staphylococcus aureus Bloodstream Infections in Nursing Homes in Monroe County, New York

Background: Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) are common in hospitals and nursing homes. Infection prevention efforts reduced MRSA BSI in hospitals but the trend in nursing homes is not well described. In addition, the contribution of methicillin sensitive S. aureus (MSSA) to the total burden of invasive S. aureus (iSA) in nursing homes remains unknown. Methods: As part of the CDC Emerging Infections Program, we conduct population-based surveillance for iSA infections in Monroe County, New York. Case patients were county residents with S. aureus isolated from a sterile site. Our analysis was limited to data from 2009–2018 for MRSA and 2015–2018 for MSSA and to cases classified as hospital-onset (HO, positive culture ≥3 calendar days after admission) or nursing home-onset (NHO, positive culture in nursing homes or within 3 days of hospital admission from a nursing home). Risk factors for iSA BSI in nursing homes were compared using the χ2 and Student t tests in SAS version 9.4 software. Results: During 2009–2014, 664 MRSA cases occurred and 427 (64%) were BSIs. Of these, 228 (53%) were NHO and 199 (47%) were HO. The BSI incidence per 100,000 population of NHO cases declined from 7.9 in 2009 to 2.8 in 2014, mirroring the decline in HO incidence from 8.7 in 2009 to 3.1 in 2014 (Fig. 1). During 2015–2018, 203 MRSA cases (163 BSIs, 80%) and 235 MSSA cases (163 BSIs, 69%) occurred. Of the 163 MRSA BSIs, 94 (58%) were NHO and 69 (42%) were HO, whereas of the 235 MSSA BSIs, only 56 (34%) were NHO and 107 (66%) were HO. MRSA BSI incidence per 100,000 population in both settings plateaued during 2015–2018 (Fig. 1) and MSSA NHO BSI incidence was lower than HO (1.9 NHO vs 3.6 HO). The total iSA BSI incidence was similar in both settings (5.9 vs 5.0 per 100,000 population in HO and NHO, respectively). NHO MSSA and MRSA cases have similar risk factors for BSI; 45 (30%) had decubitus ulcers, 34 (23%) were on chronic dialysis, 41 (27%) had a CVC in place within 2 days of BSI onset, and 63% had prior healthcare exposures. Most of these developed within 4 weeks of hospital discharge (Fig. 2). Conclusions: The incidence of MRSA BSI in nursing homes has declined since 2009 but plateaued starting in 2015. Compared to MRSA, MSSA caused fewer BSIs in nursing homes; however, iSA risk factors, including previous healthcare exposure, were similar. Continued study is needed to identify interventions effective against all iSA infections in nursing homes.Funding: NoneDisclosures: None

Discontinuing Contact Precautions for Vancomycin-Resistant Enterococcus (VRE) Is Associated With Rising VRE Bloodstream Infection Rates in Ontario Hospitals, 2009-2018: A Quasi-experimental Study.

In Ontario, Canada, since 2012, some hospitals discontinued contact precautions for vancomycin-resistant Enterococcus (VRE). Between 2009 and 2018, there was an associated rise in VRE bloodstream infections in hospitals where contact precautions were discontinued but not in hospitals that maintained contact precautions. These data suggest contact precautions are important for hospital VRE control programs.

A High Incidence of Multidrug Resistant Strains as the Agents Causing Bloodstream Infection in Hospital in Indonesia

Background: Various bacteria have been identified as the agents causing bloodstream infection. Multidrug resistant (MDR) strains, such as Gram-negative pathogens producing extended-spectrum beta-lactamases (ESBL) and Methicillin-resistant S.aureus (MRSA) are potential bacterial agents causing bloodstream infection in the hospital setting. The increase of these MDR strains in bloodstream infection is alarming since there are limited antibiotic choices for treatment. This study aimed to investigate the agents causing bloodstream infection and to investigate their antibiotics susceptibility profiles. Subjects and Method: Samples were venous blood collected from patients admitted to hospital from January 2014 to December 2016. Bacteria were grown in-automated BACTEC® blood culture (BD, New Jersey, USA). The identification of MRSA strain was conducted using oxacillin susceptibility test. The bacterial identification and identification of ESBL-producing bacteria was conducted using colorimetric assay using Vitek2®system (bioMerieux). Results: The antibiotic profiles of all bacteria isolated from venous blood samples were analysed. The most bacteria isolated from the blood stream were K. pneumonia, A. baumannii, E. coli, P. Aeruginosa, E. cloacae, S. marcennes, S. haemolyticus, S. hominis, S.epidermidis, and S. aureus. Conclusions: The resistant profiles of bacteria isolated from blood stream showed that there was a high incidence of MDR bacteria, including potential ESBL-producing bacteria, carbapenemase-producing bacteria and MRSA strains. Keywords: Bloodstream Infection, Staphylococcus aureus, Extended Spectrum Betalactamase, Antibiotic Resistance. Correspondence: Betty Suryawati. Department of Microbiology, Faculty of Medicine, Universitas Sebelas Maret, Jl. Ir. Sutami No 36A, Surakarta 57126, Central Java, Indonesia. Email: betty.suryawati@staff.uns.ac.id. Indonesian Journal of Medicine (2019), 4(1): 28-34 https://doi.org/10.26911/theijmed.2019.04.01.05

Epidemiology, management, and outcome of carbapenem-resistant Klebsiella pneumoniae bloodstream infections in hospitals within the same endemic metropolitan area.

In the last decade, carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become endemic in several countries, including Italy. In the present study, we assessed the differences in epidemiology, management, and mortality of CR-Kp bloodstream infection (BSI) in the three main adult acute-care hospitals of the metropolitan area of Genoa, Italy. From January 2013 to December 2014, all patients with CR-Kp BSI were identified through the computerized microbiology laboratory databases of the three hospitals. The primary endpoints of the study were incidence and characteristics of CR-Kp BSI in hospitals within the same endemic metropolitan area. Secondary endpoints were characteristics of CR-Kp BSI in hospitals with and without internal infectious diseases consultants (IDCs) and 15-day mortality. During the study period, the incidence of healthcare-associated CR-Kp BSI in the entire study population was 1.35 episodes per 10,000 patient-days, with substantial differences between the three hospitals. Patients admitted to the two hospital with internal IDCs were more likely to receive post-susceptibility test combined therapy including carbapenems (77% vs. 26%, p<0.001), adequate post-susceptibility test therapies (86% vs. 52%, p<0.001), and post-susceptibility therapies prescribed by an infectious diseases specialist (84% vs. 14%, p<0.001). Overall, the crude 15-days mortality was 26%. In the final multivariable model, only septic shock at BSI presentation was unfavorably and independently associated with 15-days mortality (odds ratio [OR] 6.7, 95% confidence intervals [CI] 2.6-17.6, p<0.001), while a protective effect was observed for post-susceptibility test combined therapies including a carbapenem (OR 0.11, 95% CI 0.03-0.43, p=0.002). Mortality of CR-Kp remains high. Differences in the incidence of CR-Kp BSI were detected between acute-care centers within the same endemic metropolitan area. Efforts should be made to improve the collaboration and coordination between centers, to prevent further diffusion of CR-Kp.

Recent independent emergence of multiple multidrug-resistant Serratia marcescens clones within the United Kingdom and Ireland.

Serratia marcescens, a member of the Enterobacteriaceae family, is a Gram-negative bacterium responsible for a wide range of nosocomial infections. The emergence of multidrug-resistant strains is an increasing danger to public health. To design effective means to control the dissemination of S. marcescens, an in-depth analysis of the population structure and variation is required. Utilizing whole-genome sequencing, we characterized the population structure and variation, as well as the antimicrobial resistance determinants, of a systematic collection of antimicrobial-resistant S. marcescens associated with bloodstream infections in hospitals across the United Kingdom and Ireland between 2001 and 2011. Our results show that S. marcescens is a diverse species with a high level of genomic variation. However, the collection was largely composed of a limited number of clones that emerged from this diverse background within the past few decades. We identified potential recent transmissions of these clones, within and between hospitals, and showed that they have acquired antimicrobial resistance determinants for different beta-lactams, ciprofloxacin, and tetracyclines on multiple occasions. The expansion of these multidrug-resistant clones suggests that the treatment of S. marcescens infections will become increasingly difficult in the future.

Impact of Hospital Operating Margin on Central Line-Associated Bloodstream Infections Following Medicare's Hospital-Acquired Conditions Payment Policy.

In October 2008, Medicare ceased additional payment for hospital-acquired conditions not present on admission. We evaluated the policy's differential impact in hospitals with high vs low operating margins. Medicare's payment policy may have had an impact on reducing central line-associated bloodstream infections in hospitals with low operating margins. Infect. Control Hosp. Epidemiol. 2015;37(1):100-103.

Insights into a Multidrug Resistant Escherichia coli Pathogen of the Globally Disseminated ST131 Lineage: Genome Analysis and Virulence Mechanisms

Escherichia coli strains causing urinary tract infection (UTI) are increasingly recognized as belonging to specific clones. E. coli clone O25b:H4-ST131 has recently emerged globally as a leading multi-drug resistant pathogen causing urinary tract and bloodstream infections in hospitals and the community. While most molecular studies to date examine the mechanisms conferring multi-drug resistance in E. coli ST131, relatively little is known about their virulence potential. Here we examined E. coli ST131 clinical isolates from two geographically diverse collections, one representing the major pathogenic lineages causing UTI across the United Kingdom and a second representing UTI isolates from patients presenting at two large hospitals in Australia. We determined a draft genome sequence for one representative isolate, E. coli EC958, which produced CTX-M-15 extended-spectrum β-lactamase, CMY-23 type AmpC cephalosporinase and was resistant to ciprofloxacin. Comparative genome analysis indicated that EC958 encodes virulence genes commonly associated with uropathogenic E. coli (UPEC). The genome sequence of EC958 revealed a transposon insertion in the fimB gene encoding the activator of type 1 fimbriae, an important UPEC bladder colonization factor. We identified the same fimB transposon insertion in 59% of the ST131 UK isolates, as well as 71% of ST131 isolates from Australia, suggesting this mutation is common among E. coli ST131 strains. Insertional inactivation of fimB resulted in a phenotype resembling a slower off-to-on switching for type 1 fimbriae. Type 1 fimbriae expression could still be induced in fimB-null isolates; this correlated strongly with adherence to and invasion of human bladder cells and bladder colonisation in a mouse UTI model. We conclude that E. coli ST131 is a geographically widespread, antibiotic resistant clone that has the capacity to produce numerous virulence factors associated with UTI.

Genotyping on 47 Staphylococcus aureus strains associated with bloodstream infection.

To investigate the molecular epidemiological characteristics of Staphylococcus aureus associated with bloodstream infection in hospital. 47 Staphylococcus aureus strains isolated from bloodstream in PLA General Hospital were collected from January 2006 to December 2008. Susceptibility of the strains to 11 antimicrobial agents was detected and DNA homology of them was analyzed with Rep-based DiversiLab(TM) Microbial Typing System. Panton-Valentine leukocidin (PVL) gene was determined by PCR. For methicillin-resistant Staphylococcus aureus (MRSA) strains, the genotypes of SCCmec were determined and ST239 clone was screened with multiplex PCR. Multilocus sequence typing (MLST) was used to determine the STs of the selected isolates. In the 47 Staphylococcus aureus isolated from blood, methicillin-resistant strains accounted for 51.1%, all belonged to SCCmec III type, with only 2 pvl gene positive strains identified. 12 different patterns (A-L) were found among 47 strains with Rep-PCR. All MRSA strains clustered in the A and B subtypes. Most MRSA strains isolated from blood in PLA General Hospital belonged to ST239-MRSA-SCCmec III clone. DiversiLab(TM) Microbial Typing System could provide a rapid and effective method to investigate the molecular epidemiological characteristics of Staphylococcus aureus in the hospital settings.