Community-acquired Infections Research Articles

Antibiotic-resistant Escherichia coli Undergoes a Change in mcr-1 and qnr-S Expression after being Exposed to Gamma Irradiation

Human consumption of antibiotics has increased their concentrations in many parts of the environment, including rivers, sediments, soil, and wastewater. Consequently, resistant bacteria originating from these environments are distributed to humans, resulting in illness. The aim of this study was to identify mobilized colistin-resistant (mcr) genes and quinolone-resistant (qnr) genes in E. coli strains obtained from clinical samples. Additionally, the study explored the impact of different radiation dosages on the expression of antibiotic-resistance genes. In this study, conducted in Beni-Suef, Egypt, samples from 430 community-acquired urinary tract infection (UTI) cases resulted in the isolation of 85 different strains of E. coli. Conventional microbiological procedures were employed to identify these bacterial isolates. Three bacterial isolates with resistance to both quinolones and colistin underwent examination for their corresponding genetic determinants, which subsequently proved the presence of their respective genes. Furthermore, the expression levels of the mcr-1 and qnr-S genes were assessed using real-time PCR after exposure to gamma irradiation. Remarkably, the use of a sublethal dosage of 3 kGy gamma irradiation treatment on bacterial cells increased their susceptibility to colistin and quinolones post-irradiation. Additionally, there was a notable reduction in the expression levels of both mcr-1 and qnr-S genes, which could be helpful for preventing the storage of antibiotic-resistant E. coli in the environment.

An Interprofessional Quality Improvement Project to Reduce Community-Acquired Central Line-Associated Bloodstream Infections in the Pediatric Intestinal Failure Population

Highlights Abstract Aim: Central line-associated bloodstream infections (CLABSIs) result in significant morbidity but are largely preventable. Methods to reduce hospital-acquired CLABSIs are well described, but few recommendations exist for how these practices might translate to patients with central lines in the ambulatory setting. This team sought to reduce the mean monthly community-acquired CLABSI rate by 25% from 11.7 to 8.8 per 1000 community line-days in children with intestinal failure who require home parenteral nutrition within 12 months. Methods: First, an interprofessional quality improvement team was formed. After baseline data collection, plan-do-study-act cycles began. Tests of change consisted of a central venous catheter (CVC) maintenance bundle. This bundle included a CVC care tote with additional supplies, improved educational materials, and ethanol lock prophylaxis. A control chart was used to display the monthly community-acquired CLABSI rate and observe for special cause variation. Results: At baseline, the average monthly community-acquired CLABSI rate was 11.7 per 1000 community catheter-days. The home CVC maintenance bundle was implemented, after which there were 5 consecutive months with no infections. After enhancements to the care bundle and tote, special cause variation was noted, and the average monthly community-acquired CLABSI rate declined by 66% to 4 per 1000 community catheter-days. Special cause variation was noted at 2 other time points without an identifiable cause. Conclusion: A lower community-acquired CLABSI rate has been sustained for 24 months and reflects approximately 12 fewer infections per year in this at-risk population.

2127. In vitro Activities of Ceftaroline and Comparator Agents against Bacterial Pathogens Frequently Causing Community-Acquired Respiratory Tract Infections in Patients from a Global Population: ATLAS Surveillance Program 2018-2021

Abstract Background Community-acquired bacterial pneumonia (CABP) is a frequent cause of patient morbidity and mortality. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are frequent etiologic agents of CABP. Ceftaroline fosamil is a parenteral cephem approved treatment of patients with CABP caused by S. pneumoniae (including cases with concurrent bacteremia), methicillin-susceptible Staphylococcus aureus (MSSA), H. influenzae, and some species of Enterobacterales. In this study we report the in vitro activity of ceftaroline and comparators against isolates from community-acquired respiratory tract infections (CARTI) collected through a global surveillance program. Methods Clinically relevant, non-duplicate, isolates cultured from respiratory specimens by clinical laboratories in 54 countries in 2018-2021 were collected by the ATLAS Surveillance Program central laboratory (IHMA, Schaumburg, IL, USA). Community-acquired infections were defined as those from patients < 48 hours in hospital. In total, 7,886 isolates of S. pneumoniae, H. influenzae, M. catarrhalis, MSSA, and methicillin-resistant S. aureus (MRSA) were tested. The isolates (n/percent of total) originated from Asia/South Pacific (1,893/24.0%); Europe (4,283/54.3%); Latin America (671/8.5%); Middle East/Africa (659/8.4%); and North America (Canada only) (380/4.8%). Ceftaroline and comparator agent MICs were determined by CLSI M07 broth microdilution methodology. MICs were interpreted using 2023 CLSI M100 MIC breakpoints. Results The in vitro activity of ceftaroline and comparator agents is summarized in the table. Greater than 99% of S. pneumoniae and 100% of MSSA were susceptible to ceftaroline, including penicillin-nonsusceptible S. pneumoniae based on a dosage of 600 mg every 12h. Sixty-two (9.6%) MRSA were ceftaroline-susceptible-dose-dependent (MIC 2-4 µg/mL) based on a dosage of 600 mg every 8h administered over 2h, with the majority from (n) Thailand (9), S. Korea (7), and China (6). Four isolates, from S. Korea (2), China (1), and Ukraine (1) were resistant to CPT (MIC of ≥8 µg/mL). 99.6% of H. influenzae were susceptible to ceftaroline. Conclusion Ceftaroline demonstrated potent in vitro activity against current pathogens associated with CABP from a global collection. Disclosures Meredith Hackel, PhD, Pfizer Inc.: Honoraria|Venatorx: Paid fees for conducting the study and abstract preparation Gregory Stone, PhD, Pfizer: Stocks/Bonds Daniel F. Sahm, PhD, Merck & Co., Inc.: Honoraria|Pfizer Inc.: Honoraria|Venatorx: Paid fees for conducting the study and abstract preparation

2235. Characterization of the Adult Sepsis Treatment Guideline Utilization Within the Emergency Department at an Academic Medical Center

Abstract Background The early initiation of antibiotics in patients with sepsis has been identified as the most effective intervention in reducing mortality. Screening tools have been developed for the early identification of sepsis. This study characterized Emergency Department (ED) patients initiated on antibiotics for suspected sepsis of urinary or abdominal sources to identify opportunities to improve institutional sepsis guidelines. Methods A retrospective chart review was performed of patients initiated on empiric antibiotics in the ED for sepsis with a suspected source of urinary tract infection (UTI) or intraabdominal infection (IAI) from September 2021 to September 2022. Epic SlicerDicer, an electronic medical record (EMR) data extraction tool, identified ED patients with an order for broad-spectrum antibiotics. Patients less than 18 years or initiated on antibiotics prior to arrival were excluded. The EMR was utilized to assess the signs of organ dysfunction, antibiotic regimen, EMR-based sepsis pathway use, and patient-specific risk factors. Institutional guidelines defined antibiotic regimen appropriateness. Descriptive statistics were used to characterize the results. Results Among the 6869 patients screened, 190 patients were included. The provider initiated the sepsis pathway in 141 (74.2%) patients, and 21 (14.9%) were initiated on empiric antibiotics determined to be congruent with institutional guidelines. The most common deviation from institutional guidelines was the addition of anti-methicillin-resistant Staphylococcus aureus (MRSA) treatment. Anti-pseudomonal therapy was used in 165 (86.8%) patients and anti-MRSA coverage in 117 (61.6%) patients. Of patients with MRSA coverage, 36 (30.8%) had community-acquired infections. An organism was isolated in 113 (59.5%) patients, and Enterobacterales were most commonly isolated (65.5%). P. aeruginosa was isolated in 15 (7.9%) patients, and no patients had MRSA. Conclusion Most antibiotic regimens used in ED patients for the treatment of sepsis with suspected urinary or abdominal sources of infection were contrary to institutional guidelines. This may be a result of an overestimation of MRSA or P. aeruginosa in community-acquired infections, highlighting an opportunity for education and stewardship. Disclosures Christina Maguire, PharmD, Viiv: Advisor/Consultant Amanda Binkley, PharmD, BCIDP, AAHIVP, Viiv: Advisor/Consultant

2794. Assessing the impact of inappropriate antibiotic therapy on mortality among intensive care unit patients

Abstract Background This study evaluates the potential association between inappropriate antibiotic therapy and adverse clinical outcomes in infected patients admitted to ICUs. Methods We analyzed data from infected patients admitted to a medical-surgical Intensive Care Unit (ICU) in Belo Horizonte, a city with a population of three million in Brazil. The data was collected between January 2020 and June 2021, and included patients with healthcare-associated and community-acquired infections. In order to determine the appropriateness of antibiotic therapy, cultures and susceptibility reports were utilized. Empiric antimicrobial therapy was classified as inappropriate if the isolated strain was resistant to all empirically administered antimicrobials, while it was considered adequate if the isolated strain was susceptible to at least one of the antimicrobials used empirically. Results A total of 470 patients who received antimicrobials in the ICU were included in the analysis, all of whom had a positive culture. Among them, 65 patients experienced a FAILURE of the antimicrobial regimen, resulting in an overall failure rate of 14%. The monthly rate of inappropriate antibiotic therapy showed significant heterogeneity during the study period, ranging from 100% success in March 2021 to a failure rate of 33% in June 2021 (Fig 1). The failure rate of antimicrobial regimen was found to be significantly higher in cases where the infection was caused by multidrug-resistant (MR) strains compared to multisensitive (MS) strains, as shown in Table 1. Failure of the antimicrobial regimen was a significant risk factor for patient death, regardless of whether the infection was caused by MS or MR strains (Tables 1 and Fig 2). Patients who died tended to receive more antimicrobials compared to those who were discharged, with an average of three antimicrobials prescribed for patients who progressed to death, while discharged patients received an average of two drugs. Conclusion Inappropriate antibiotic therapy in ICU patients is associated with increased mortality risk, regardless of the type of infection. Timely and appropriate antimicrobial therapy is crucial in the management of ICU infections to improve clinical outcomes. Disclosures All Authors: No reported disclosures

A multiplex Taqman PCR assay for MRSA detection from whole blood.

Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide range of hospital and community-acquired infections worldwide. MRSA is associated with worse clinical outcomes that can lead to multiple organ failure, septic shock, and death, making timely diagnosis of MRSA infections very crucial. In the present work, we develop a method that enables the positive enrichment of bacteria from spiked whole blood using protein coated magnetic beads, followed by their lysis, and detection by a real-time multiplex PCR directly. The assay targeted bacterial 16S rRNA, S. aureus (spa) and methicillin resistance (mecA). In addition, an internal control (lambda phage) was added to determine the assay's true negative. To validate this assay, staphylococcal and non-staphylococcal bacterial strains were used. The three-markers used in this study were detected as expected by monomicrobial and poly-microbial models of the S. aureus and coagulase-negative staphylococci (CoNS). The thermal cycling completed within 30 mins, delivering 100% specificity. The detection LoD of the pre-processing step was ∼ 1 CFU/mL from 2-5mL of whole blood and that of PCR was ∼ 1pg of NA. However, the combined protocol led to a lower detection limit of 100-1000 MRSA CFUs/mL. The main issue with the method developed is in the pre-processing of blood which will be the subject of our future study.

Stenotrophomonas maltophilia Belonging to Novel Sequence Types ST473 and ST474 in Wild Birds Inhabiting the Brazilian Amazonia.

Stenotrophomonas maltophilia is an opportunistic human pathogen associated with nosocomial and community-acquired infections. We have conducted a microbiological and genomic surveillance study of broad-spectrum cephalosporin- and carbapenem-resistant Gram-negative bacteria colonizing wild birds inhabiting the Brazilian Amazonia. Strikingly, two S. maltophilia strains (SM79 and SM115) were identified in Plain-throated antwren (Isleria hauxwelli) passerines affected by Amazonian fragmentation and degradation. Noteworthy, SM79 and SM115 strains belonged to new sequence types (STs) ST474 and ST473, respectively, displaying resistance to broad-spectrum β-lactams, aminoglycosides and/or fluoroquinolones. In this regard, resistome analysis confirmed efflux pumps (smeABC, smeDEF, emrAB-tolC and macB), blaL1 and blaL2, aph(3')-IIc and aac(6')-Iak, and Smqnr resistance genes. Comparative phylogenomic analysis with publicly available S. maltophilia genomes clustered ST473 and ST474 with human strains, whereas the ST474 was also grouped with S. maltophilia strains isolated from water and poultry samples. In summary, we report two novel sequence types of S. maltophilia colonizing wild Amazonian birds. The presence of opportunistic multidrug-resistant pathogens in wild birds, from remotes areas, could represent an ecological problem since these animals could easily promote long-distance dispersal of medically important antimicrobial-resistant bacteria. Therefore, while our results could provide a baseline for future epidemiological genomic studies, considering the limited information regarding S. maltophilia circulating among wild animals, additional studies are necessary to evaluate the clinical impact and degree of pathogenicity of this human opportunistic pathogen in wild birds.

Topical antimicrobial formulations using medicinal plant-derived essential oils targeting methicillin resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) causes a variety of healthcare-associated and community-acquired infections. Due to limited availability of effective antimicrobials for treating MRSA infections, there is a growing need to explore alternative therapeutic approaches. Here, the antimicrobial activities of 19 oils, popularly used for their medicinal properties, were tested against MRSA USA300. Oils obtained from cinnamon, clove, tangerine, and coriander showed the most promising activities, demonstrating bactericidal, anti-adhesive and anti-biofilm activities, and synergistic properties with common antibiotics. Given that clove and cinnamon oils showed the best activities, they were incorporated into topical formulations. Not only did the formulations with oils maintain antimicrobial and anti-adhesive activities, but their anti-biofilm property was potentiated. Tests on Galleria mellonella larvae suggested that the formulation is non-toxic. The formulations proposed here are a great alternative for the decolonisation of surfaces containing MRSA and can help circumventing antimicrobial resistance, a growing threat in the hospital environment.

Physical Education Moving From Marginalized to Materialized

Undoubtedly, the world has seen drastic changes after the COVID-19 outbreak. The pandemic has also solidified the importance of children’s immunity, health, and physical activity (PA). Regular PA is considered an investment for the future, which will increase the quality of life of all people. Specific to COVID-19, evidence suggests that PA promotes resistance to infectious diseases and should be encouraged among the general population to lower the risk of community-acquired infection and infectious disease mortality. Physical education (PE) is a crucial subject in the school that strives to give children and youth learning opportunities that help them develop the understanding, desire, and capacity to lead physically active lives. While in the past the role of PE in abating childhood obesity has been espoused to questionable success, in this post-pandemic era, it is argued that PE must capitalize on the widely recognized need to increase youth PA. Here, we charge PE to actualize its potential and move from being marginalized to materializing its role in helping students identify PA as an essential part of their lives.

Involvement of Tn3 transposon in formation and transmission of hypervirulent and carbapenem-resistant Klebsiella pneumoniae

ABSTRACT Hypervirulent and carbapenem-resistant Klebsiella pneumoniae poses a severe threat to public health for its high pathogenicity, transmissibility, and drug resistance. This study aims to explore the evolutionary path and the role of Tn3 transposon in the virulence and carbapenem resistance transmission of K. pneumoniae . Bioinformatics analysis and some experimental tests such as plasmid conjugation experiments, antimicrobial susceptibility testing, and virulence-associated tests were performed to explore the virulence and drug resistance transmission. The complete genome sequencing, S1 nuclease pulsed-field gel electrophoresis, and bioinformatics analysis were used to investigate their transmission mechanism mediated by Tn3 transposons. Three hypervirulent and carbapenem-resistant K. pneumoniae isolates, which were obtained from different patients at different time points in the same ward, harbored a virulence plasmid and a carbapenem resistance plasmid. They were confirmed to have first evolved from hypervirulent isolates and then acquired a bla KPC -positive plasmid (CR-hvKp evolutionary pattern). The non-conjugative virulence plasmid pVir could be transferred to other bacterial strains via mobilization by the conjugative IncN/U-type plasmid pKPC, as well as by fusing with the conjugative pKPC plasmid (mediated by Tn3-based homologous recombination) to be self-transmissible, thus transferring drug resistance and virulence. The cointegration, pVir/KPC fusion plasmid, was further resolved into pVir and pKPC between the duplicated copies of the Tn3 transposon resolution site mediated by site-specific recombination. Therefore, Tn3 transposons can mediate hypervirulent and carbapenem-resistant K. pneumoniae strains transferring drug resistance and virulence to other bacteria. We must be vigilant to emerging transposon-mediated hypervirulent and carbapenem-resistant pathogens. IMPORTANCE Carbapenem-resistant Klebsiella pneumoniae (CRKP) is resistant to most common antibiotics, becoming the most important and prevalent nosocomial opportunity pathogen. Besides, K. pneumoniae can also cause severe community-acquired infections, such as primary liver abscess and endophthalmitis. These pathogens are commonly referred to as hvKp. CRKP and hvKp have evolved separately, each occupying its own clonal lineage and exhibiting a variety of properties. Our study provides important insights into the evolutionary events related to the arousal of virulence and drug resistance in K. pneumoniae through plasmid transmission, mediated by Tn3 transposon. Our study also provides evidence that multiple mechanisms contribute to the successful transfer of non-conjugative virulence plasmid, and the involvement of transposons enhances the efficiency. A good knowledge of its transmission mechanisms is fundamental to finding effective strategies to combat these threatening pathogens. Transposons are widely present in bacteria, spreading resistance and virulence genes between the environment and humans. Therefore, emerging transposon-mediated hypervirulent and carbapenem-resistant pathogens should be highly valued.

Cytokine profile and viral diversity in the early seronegative stage of community-acquired hepatitis C virus (HCV) infection

Most Hepatitis C virus (HCV)-infected subjects develop chronic infection, whereas a minority clear the virus in the early phase of infection. We analyzed factors associated with outcome (chronicity vs clearance) during the preclinical seronegative phase of community-acquired HCV infection. Among 17.5 million blood donations in the years 2000–2016, 124 blood donors were found to be HCV RNA-positive/anti-HCV-negative. All were contacted after 0.5–12.7 years and 40 responded and provided blood sample. Hypervariable region 1 was analyzed by ultradeep pyrosequencing and cytokines in serum were quantified by Luminex (R&D Systems) multiplex immunoassay. Twenty-one (52.5%) donors were found to be HCV-RNA-positive, while 19 (47.5%) were HCV RNA negative (none received antiviral treatment). All but one seroconverted to anti-HCV. Donors with resolving hepatitis did not differ significantly from donors with chronic infection with respect to age, genotypes, IL28B polymorphisms, number of viral variants, nucleotide diversity per site or the overall number of nucleotide substitutions. However, the former group had significantly higher levels of IL-1beta, IL-1RA, IL-6, IFN-gamma and FGF-2 in serum. In our study of community-acquired acute hepatitis C approximately half of all subjects eliminated the virus spontaneously, and this clearance was associated with marked cytokine response in the early seronegative stage of infection.

Current insight into klebsiella infection in children

Klebsiella pneumoniae is an important causative agent of nosocomial and community-acquired infections in children. The relevance of Klebsiella infection has increased in recent years due to the spread of multiresistant and hypervirulent strains that can cause invasive forms of infection (sepsis, meningitis, liver abscess, etc.). Strains of Kl. pneumoniae, producing extended-spectrum β-lactamase (ESBL), as well as carbapenem-resistant strains, are the cause of nosocomial outbreaks with high mortality. The choice of antibacterial drugs for the treatment of invasive forms of infection is limited and depends on the spectrum of sensitivity to antimicrobial drugs of Klebsiella clinical isolates circulating in the hospital and the age of the child. Due to the high rate of ESBL production, carbapenems are the drugs of choice in the empirical therapy of invasive forms of infection.

Detection of Methicillin-Resistant Staphylococcus Aureus using vancomycin conjugated silica-based fluorescent nanoprobe

Methicillin-Resistant Staphylococcus Aureus (MRSA) is a worldwide major pathogenic bacteria that has emerged over the past three decades as the leading cause of nosocomial and community-acquired infections. Biosensors can provide rapid, sensitive, and selective detection of the presence and number of bacteria in various environments. Herein, a novel fluorescence nanoprobe was designed as a biosensor for MRSA detection using dye-incorporated silica nanoparticles (FSiNP). Based on the results of specific surface area analysis using the Brauner Emmett-Teller (BET) method, the surface area of the nanoparticles was obtained at 377.127 m2/g, and the X-ray diffraction (XRD) analysis confirmed that it was in the amorphous phase. Vancomycin, as the bioreceptor, was immobilized on the silica surface through a hydrosilylation reaction, generating the biosensing platform FSiNP-Van. Each modification step was corroborated by the Fourier Transform Infra-Red (FTIR) spectroscopy. The sensing principle was based on the fluorescence-quenching mechanism of FSiNP-Van at 515 nm obtaining a rapid response time of 20 min. The FSiNP-Van nanoprobe provided a wide linear concentration range of 10–106 CFU/mL with a limit of MRSA detection calculated at 1 CFU/mL. The fluorescent nanoprobe demonstrated here is expected to find applications in point-of-care (POC) diagnostics to detect the presence of MRSA bacteria.

PREDICTION OF THE RISK OF ANTIBIOTIC RESISTANCE OF UROPATHOGENS IN PATIENTS WITH URINARY TRACT INFECTIONS

Urinary tract infection is the most common disease in urological practice. The growth of antibiotic resistance in general and in urological practice in particular determines the need to develop methods for determining the risks of the presence of microflora resistance to antimicrobial drugs. The article discusses the existing methods for predicting the resistance of microorganisms to antibiotics, as well as the risk factor for antibiotic resistance developed by the author in community-acquired urinary tract infections. This indicator takes into account the individual characteristics and clinical and laboratory data of the patient with urinary tract infections that occur against the background of urolithiasis.

Prevalence of Carbapenem-Resistant Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa in a Tertiary Care Hospital in Eastern India: A Pilot Study

In recent years, a wide range of clinical infections are being caused by carbapenem-resistant Enterobacterales, Acinetobacter baumannii and Pseudomonas aeruginosa. This is a matter of great concern, as carbapenem-resistant infections have fewer treatment options. The Enterobacterales comprises a large group of bacterial species commonly causing infections in healthcare settings. The most common bacteria are Escherichia coli and Klebsiella pneumoniae, which can cause both nosocomial and community-acquired infections. This study aimed to determine the prevalence of carbapenem-resistant Enterobacterales, P. aeruginosa, and A. baumannii, in a tertiary care center in India. The study was conducted over a period of seven months, from May 2022 to November 2022. The specimens were processed at the Microbiology Laboratory of Kalinga Institute of Medical Sciences- Pradyumna Bal Memorial Hospital, Bhubaneswar. Standard procedures were used to process the clinical specimens brought to the laboratory. Carbapenem-resistant isolates were screened according to the CLSI 2022 guidelines. This study included 3,006 isolates of Enterobacterales, A. baumannii, and P. aeruginosa. Of these, 29.40% (n = 844) were found to be carbapenem resistant. The breakup is as follows: 689 (77.94%) were Enterobacterales, 108 (12.21%) were A. baumannii, and 87 (9.84%) were P. aeruginosa. Thus, our investigation revealed an overall prevalence of carbapenem-resistant Enterobacterales, A. baumannii, and P. aeruginosa of 29.40%, which corresponds to previous studies in India. Early patient screening, isolation, and contact prevention measures will help reduce infection transmission. Further, larger multi-centric studies are required to obtain a wider perspective regarding this issue.

VI. Clinical Pearls for Community-acquired Systemic Infections

VI. Clinical Pearls for Community-acquired Systemic Infections

Point Prevalence Survey of Antimicrobial Use and Resistance during the COVID-19 Era among Hospitals in Saudi Arabia and the Implications.

The inappropriate prescribing of antimicrobials increases antimicrobial resistance (AMR), which poses an appreciable threat to public health, increasing morbidity and mortality. Inappropriate antimicrobial prescribing includes their prescribing in patients hospitalized with COVID-19, despite limited evidence of bacterial infections or coinfections. Knowledge of current antimicrobial utilization in Saudi Arabia is currently limited. Consequently, the objective of this study was to document current antimicrobial prescribing patterns among Saudi hospitals during the COVID-19 pandemic. This study included patients with or without COVID-19 who were admitted to five hospitals in Makkah, Saudi Arabia. Data were gathered using the Global PPS methodology and analyzed using descriptive statistics. Out of 897 hospitalized patients, 518 were treated with antibiotics (57.7%), with an average of 1.9 antibiotics per patient. There were 174 culture reports collected, representing 36.5% of all cases. The most common indication for antibiotics use was community-acquired infections, accounting for 61.4% of all cases. 'Watch' antibiotics were the most commonly prescribed antibiotics, with the cephalosporins and carbapenems representing 38.7% of all antibiotics prescribed, followed by the penicillins (23.2%). Notably, Piperacillin/Tazobactam and Azithromycin were prescribed at relatively higher rates for COVID-19 patients. These findings highlight the need for continuous efforts to optimize the rational use of antibiotics through instigating appropriate antimicrobial stewardship programs in hospitals and, as a result, reduce AMR in the country.

Contemporary profile of infective endocarditis in young patients in the era of ageing population: a comparative study

Abstract Aim The aim of the study is to describe the main differences in epidemiological characteristics, clinical features and prognosis between IE patients aged <50 and ≥50 years. Methods A total of 1935 episodes of IE were prospectively recruited at three tertiary centres from 1996 to 2022. Patients were classified into two groups: <50 years (n=333, median age 40 [IQR 33-45] and ≥50 years (n=1602, median age 71 [IQR 64-78]). Variables related to epidemiology, microbiology, echocardiography and outcomes among both groups were analysed. Results The proportion of male patients was higher in those <50 years (73.9% vs 64%; p<0.001). Patients aged ≥50 years had more comorbidities. Time to diagnosis was longer in this group of patients (6.2 ± 1.5 vs 21.7 ± 14.12 days; p<0.001). Proportion of community-acquired IE was higher in <50-year episodes (64.4% vs 81%; p<0.001). Intravenous drug use (IVU) was significantly more frequent in younger patients (22.6% vs 0.5%; p<0.001). Likewise, tricuspid native valve IE was more common in patients <50 years old (16.6% vs 4%; p<0.001). Congenital heart disease (17.2% vs 2.7%; p<0.001) and mitral valve prolapse (6.3% vs 3.8%; p=0.041) were more frequent in patients aged<50 years. Conversely, prosthetic valve IE (38.4% vs 20.7%; p<0.001) was more common in patients >50 years. Streptococcus bovis (0.9% vs 5.6%; p<0.001), enterococci (3% vs 12.6%; p=0.000), coagulase-negative staphylococci (9.9% vs 18.4%; p<0.001) and gram-negative bacilli (1.2% vs 3.5%; p=0.028) infections were more frequent in ≥50-year adults, while the incidence of Streptococcus viridans (21.9% vs 10.7%; p<0.001) and HACEK (1.2% vs 0.3%; p=0.03) infections was higher in the <50-year group. Staphylococcus aureus IE was similar between the two groups (23.7% vs 19.4%; p=0.074). The presence of vegetations (87.4% vs 80.9%; p=0.005), as well as severe new valve regurgitation (42% vs 30.8%; p<0.001) were more often found in <50-year patients. Acute heart failure (44.1% vs 59.5%; p<0.001), acute kidney failure (27.3% vs 47.5%; p<0.001) and septic shock (15.3% vs 20.9%; p=0.02) were more frequent in >50-year group. No differences in frequency of cardiac surgery among both groups were found (61.9% vs 57.6%; p=0.147). In-hospital mortality was significantly higher in ≥50-year patients (15.6% vs 29.2%; p<0.001). Mortality remained higher in ≥50-year adults who underwent cardiac surgery (12.4% vs 23.3%; p=0.001) as well as those who did not undergo surgery (20.5% vs 37.2%; p<0.001). Conclusions Patients aged <50 years diagnosed with IE were more frequently male, and had a higher proportion of community-acquired infections. Congenital heart disease, mitral valve prolapse and IVU were more frequent in <50-year adults. Streptococcus viridans infections were more frequent in this group of patients. In-hospital complications and mortality were lower compared to older patients, regardless of whether they underwent cardiac surgery.

Detection and characterization of putative hypervirulent Klebsiella pneumoniae isolates in microbiological diagnostics

Hypervirulent Klebsiella pneumoniae strains (hvKp) can cause invasive community-acquired infections in healthy patients of all ages. In this study, the prevalence of putative hvKp in a German tertiary center was investigated and hvKp were characterized by phenotypic and molecular assays. All K. pneumoniae isolates in routine microbiological diagnostics from a single center were screened by string-testing over a period of 6 months. String-test positive (≥ 0.5 mm) isolates were re-evaluated on different media and under various conditions (aerobe, anaerobe). For string-test positive isolates, genes (magA, iutA, rmpA and rmpA2) associated with hypermucoviscosity and hypervirulence were amplified by multiplex PCR. PCR-positive isolates were subjected to whole-genome sequencing and sedimentation and biofilm formation assays. From 1310 screened K. pneumoniae isolates in clinical routine 100 isolates (7.6%) were string test positive. From these, 9% (n = 9) were defined as putative hvKp (string-test+/PCR+). Highest rate of string-test-positive isolates was observed on MacConkey agar under aerobic conditions. Amongst these nine putative hvKp isolates, the international lineage ST23 carrying hvKp-plasmid pKpVP-1 was the most common, but also a rare ST86 with pKpVP-2 was identified. All nine isolates showed hypermucoviscosity and weak biofilm formation. In conclusion, 9% of string-positive, respectively 0.69% of all K. pneumoniae isolates from routine were defined as putative hypervirulent. MacConkey agar was the best medium for hvKp screening.

The success of publicly funded rotavirus vaccine programs for preventing community- and hospital-acquired rotavirus infections in Canadian pediatric hospitals: an observational study.

Canadian immunization programs for rotavirus started in 2011. We sought to determine their effect on the burden of community-acquired admissions and hospital-acquired rotavirus at pediatric hospitals. The Canadian Immunization Monitoring Program Active (IMPACT) network conducted active surveillance for rotavirus-positive hospital admissions between 2005 and 2020 at 12 pediatric hospitals. We used yearly rates of community-acquired rotavirus per 10 000 admissions and hospital-acquired rotavirus infections per 1000 patient-days to determine changes in the pre- and post-vaccine program periods. During the 15-year study period, 5691 rotavirus hospital admissions and hospital-acquired infections were detected, including 4323 (76%) community-acquired infections and 1368 (24%) hospital-acquired infections. The average community-acquired rate in the pre-vaccine period was 60.3 (95% confidence interval [CI] 53.7-68.3) per 10 000 admissions, with a decline to 11.0 (95% CI 7.5-15.1) per 10 000 admissions in the post-vaccine period, resulting in an average reduction of 81.7% (95% CI 74.4%-87.8%). The rate of hospital-acquired rotavirus declined from 0.35 (95% CI 0.29-0.41) per 1000 patient-days in the pre-vaccine period to 0.05 (95% CI 0.03-0.07) per 1000 patient-days in the post-vaccine period, resulting in an 85.3% (95% CI 77.7%-91.9%) average decline. Herd protection was present among children aged 2-16 years. Although start dates of rotavirus vaccine programs across provinces varied, there was around an 80% average decrease in both community-acquired and hospital-acquired rotavirus infections at pediatric hospitals in Canada in the 1- to 9-year interval after implementation of rotavirus vaccine programs. Herd protection is an important aspect of rotavirus vaccines for other children who are not vaccine eligible, and rotavirus vaccines continue to provide important benefits both for children and health care systems.