Empiric Antibiotic Selection Research Articles

UROLOGISTS’ KNOWLEDGE AND PERCEPTIONS ABOUT MANAGEMENT OF INFECTIONS AND ANTIBIOTIC RESISTANCE

OBJECTIVE. The correct management of infections is a point of paramount importance. Therefore, evaluating the degree of knowledge of all these factors and analysis of possible issues of improvement will result in better health care. We aimed to assess the perceptions about antibiotics prescription and bacterial resistance among urologists. MATERIALS & METHODS. A self-administered questionnaire designed to evaluate the degree of knowledge in the antibiotic treatment of infections. We adapted a questionnaire developed by Pulcini and modified by Navarro-San Francisco. Most of the questions were assessed with a 5-point Likert-style scale with response options from very unhelpful/unimportant/ unconfident to very helpful/important/confident. RESULTS. The survey was completed by 176 urologists. Only 4.5% (8) have been training in an infectious diseases department, and 80.1% prescribed more than three antibiotics per week. Although most the urologists feel confident about the antibiotic selection (97,7%), the percentage that was not confident about interactions with other drugs was 41,7%. Most responders perceived antimicrobial resistance as a significant problem (99.4%). The local prevalence of E. coli resistance to quinolones was not accurately known by 31% of the responders. Moreover, 35% of the responders considered that the percentage of patients where the selection of empirical antibiotics was not adequate in 11–20% of the prescriptions and 37% in >21% of the prescriptions. CONCLUSIONS. Although the confidence among urologists in the management of infection is high, several points require attention, such as measures for better training regarding prescription and prevention of multidrug-resistant microorganisms.

Long-term Risk of Infection Among Patients Colonized With Antimicrobial-Resistant Pathogens: A Population-wide Cohort Study.

Antimicrobial-resistant (AMR) pathogens represent an ongoing global health burden. Colonization is often a prerequisite for infection, but the risk of infection after AMR colonization is not well understood. Using population-level health administrative data, we sought to investigate the risk of infection with the same AMR organism after detection of colonization. We conducted a retrospective population-wide cohort study among residents of Ontario, Canada, over a 5-year period to determine the risk of infection after detection of colonization with the following AMR pathogens: methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended-spectrum β-lactamase-producing Enterobacterales, and carbapenemase-producing Enterobacterales. We also examined the effects of age, sex, and health care setting of colonization detection on subsequent infection risk. There were 69 998 individuals with a positive AMR pathogen surveillance test result during the study period, 15.6% of which subsequently developed a sterile or nonsterile site infection within a median 57 days (IQR, 11-228). Infection rates varied among organisms: 18.3% for methicillin-resistant S aureus within a median 57 days (IQR, 10-239), 2.8% for vancomycin-resistant Enterococcus within a median 37 days (IQR, 11-119), 21.5% for extended-spectrum β-lactamase-producing Enterobacterales within a median 71 days (IQR, 18-231), and 20.3% for carbapenemase-producing Enterobacterales within a median 10 days (IQR, 3-42). A positive surveillance test result detected in a hospital was associated with increased infection risk after colonization as compared with the community setting. The overall infection rate after colonization with an AMR pathogen was high for most organisms, highlighting the importance of detecting colonization from both an infection control and empiric antibiotic selection perspective.

Rapid inference of antibiotic susceptibility phenotype of uropathogens using metagenomic sequencing with neighbor typing.

Urinary tract infections (UTIs) are a common diagnosis in hospitals and are often treated empirically with broad-spectrum antibiotics. These broad-spectrum agents can select for resistance in these bacteria and co-colonizing organisms. The use of narrow-spectrum agents is desirable as an antibiotic stewardship measure; however, it is counterbalanced by the need for adequate therapy. Identification of causative organisms and their antibiotic susceptibility can help direct treatment; however, conventional testing requires days to produce actionable results. Methods to quickly and accurately predict susceptibility phenotypes for pathogens causing UTI could thus improve both patient outcomes and antibiotic stewardship. Here, expanding on previous work showing accurate prediction for certain Gram-positive pathogens, we demonstrate how the use of RASE from metagenomic sequencing can provide informative and rapid phenotype prediction results for common Gram-negative pathogens in UTI, highlighting the future potential of this method to be used in clinical settings to guide empiric antibiotic selection.

Real-time evaluation of macozinone activity against Mycobacterium tuberculosis through bacterial nanomotion analysis.

Novel drugs and improved diagnostics for Mycobacterium tuberculosis (MTB) are urgently needed and go hand in hand. We evaluated the in vitro activity of two benzothiazinone drug candidates (MCZ, PBTZ169; BTZ043) and their main metabolites against MTB using advanced nanomotion technology. The results demonstrated significant reductions in MTB viability within 7 h, indicating the potential for rapid, precise antibiotic susceptibility testing based on a phenotypic read-out in real time. PBTZ169 and H2-PBTZ169 achieved 100% separation between the susceptible H37Rv and a resistant dprE1 mutant strain NTB1. These findings support nanomotion technology's potential for faster antibiotic susceptibility testing of novel MTB drug candidates targeting the DprE1 enzyme that could reduce empirical treatment duration and antibiotic resistance selection pressure due to inaccurate treatments.

Bacteriological Profile and Antimicrobial Resistance Patterns in Pediatric Urinary Tract Infections: A Cross-Sectional Study at Dhaka Shishu Hospital

Urinary tract infections (UTIs) are a prevalent concern in pediatric healthcare, causing distress to children, raising parental concerns, and potentially leading to lasting kidney damage. The highest incidence of first-time symptomatic UTIs occurs in infants during the first year of life, with a subsequent marked decrease. Febrile infants under 2 months, presenting with unexplained fever, constitute a critical subset requiring particular attention. Knowledge of the bacteriological profile and antimicrobial resistance patterns in specific regions is crucial for guiding effective treatment strategies. Methods: A cross-sectional study was conducted at 250 Bedded General Hospital, Jamalpur, Bangladesh from Feb 2016 to Aug 2016 to assess the bacteriological profile and antibiotic resistance patterns in pediatric UTIs. A total of 147 culture-positive UTI patients were included. Bacterial isolates were identified, and colony counts for samples with ≥105 CFU/mL bacteria were considered positive. Antimicrobial susceptibility testing was performed using twelve agents, and resistance patterns were analyzed. Results: Among the 147 culture-positive UTI patients, Escherichia coli (E-coli) was the predominant isolate (70%), followed by Klebsiella spp. (13.6%), Pseudomonas (5.44%), Enterobacter spp (3.40%), Staphylococcus Aureus (3.40%), Proteus (2.72%), and Enterococcus (1.36%). Antimicrobial resistance analysis revealed varying patterns, with Cefradine (79.59%), Co-trimoxazole (SXT) (69.39%), Nalidixic acid (NA) (66.67%), and Ceftazidime (CTM) (48.98%) showing higher resistance rates. No drug exhibited 100% resistance against urinary pathogens, indicating a dynamic resistance landscape. Conclusion: This study highlights the importance of understanding local prevalence and resistance patterns in guiding empirical antibiotic selection for pediatric UTIs. The observed decrease in antimicrobial resistance underscores the need for continuous surveillance and tailored antibiotic strategies. Clinicians should base their treatment decisions on the specific epidemiological context rather than relying solely on universal or national guidelines.

A multicentre prospective registry of one thousand sepsis patients admitted in Indian ICUs: (SEPSIS INDIA) study

BackgroundSepsis is a global health problem with high morbidity and mortality. Low- and middle-income countries have a higher incidence and poorer outcome with sepsis. Large epidemiological studies in sepsis using Sepsis-3 criteria, addressing the process of care and deriving predictors of mortality are scarce in India.MethodA multicentre, prospective sepsis registry was conducted using Sepsis 3 criteria of suspected or confirmed infection and SOFA score of 2 or more in 19 ICUs in India over a period of one year (August 2022–July 2023). All adult patients admitted to the Intensive Care Unit who fulfilled the Sepsis 3 criteria for sepsis and septic shock were included. Patient infected with Covid 19 were excluded. Patients demographics, severity, admission details, initial resuscitation, laboratory and microbiological data and clinical outcome were recorded. Performance improvement programs as recommended by the Surviving Sepsis guideline were noted from the participating centers. Patients were followed till discharge or death while in hospital.ResultsRegistry Data of 1172 patients with sepsis (including 500 patients with septic shock) were analysed. The average age of the study cohort was 65 years, and 61% were male. The average APACHE II and SOFA score was 21 and 6.7 respectively. The majority of patients had community-acquired infections, and lung infections were the most common source. Of all culture positive results, 65% were gram negative organism. Carbapenem-resistance was identified in 50% of the gram negative blood culture isolates. The predominant gram negative organisms were Klebsiella spp (25%), Escherechia coli (24%) and Acinetobacter Spp (11%). Tropical infections (Dengue, Malaria, Typhus) constituted minority (n = 32, 2.2%) of sepsis patients. The observed hospital mortality for the entire cohort (n = 1172) was 36.3%, for those without shock (n = 672) it was 25.6% and for those with shock (n = 500) it was 50.8%. The average length of ICU and hospital stay for the study cohort was 8.64 and 11.9 respectively. In multivariate analysis adequate source control, correct choice of empiric antibiotic and the use of intravenous thiamine were protective.ConclusionThe general demographics of the sepsis population in the Indian Sepsis Registry is comparable to Western population. The mortality of sepsis cohort was higher (36.3%) but septic shock mortality (50.8%) was comparable to Western reports. Gram negative infection was the predominant cause of sepsis with a high incidence of carbapenem resistance. Eschericia coli, Klebsiella Spp and Acinetobacter Spp were the predominant causative organism. Tropical infection constituted a minority of sepsis population with low hospital mortality. The SOFA score on admission was a comparatively better predictor of poor outcome. Sepsis secondary to nosocomial infections had the worst outcomes, while source control, correct empirical antibiotic selection, and intravenous thiamine were protective.CTRI Registration CTRI:2022/07/044516.

Pathogen Distribution of Neonatal Bacterial Meningitis in the Era of Multidrug-Resistant Bacteria: A Single-Center Experience.

Neonatal bacterial meningitis (NBM) is a serious disease with high morbidity and mortality. This study aimed to establish a foundation for the selection of empirical antibiotics for NBM through an analysis of pathogen distribution and shift in antimicrobial resistant pattern. A retrospective cohort study on culture confirmed NBM from 2005 to 2022. A total of 191 cases were enrolled, 48 for premature infants and 70 for early-onset meningitis. The incidence of NBM in first half and last half period was 0.2‰ and 0.24‰, while the mortality was 12.0% and 5.6% respectively. The top two pathogens were Escherichia coli (E. coli) (40.3%) and Group B Streptococcus (GBS) (29.8%). E. coli was the most common pathogen in both periods, Enterococcus (13.3% vs 0.9%, P < 0.05) and Staphylococcus aureus (8.4% vs 1.9%, P < 0.05) decreased, while GBS increased significantly in the periods [16.9% vs 39.8%, P < 0.001]. Gram-positive bacteria were more common in full term infants (53.8% vs 27.1%, P = 0.001), while gram-negative bacteria were more common in preterm infants (72.9% vs 46.2%, P = 0.001). All isolated GBS strains were susceptible to penicillin. On the other hand, less than 60% of E. coli were susceptible to third generation of cephalosporins, and were only susceptible to carbapenem or amikacin. This was mainly due to production of extended-spectrum beta-lactamase (ESBLs) which was higher in late-onset group than that in early-onset group (45.1% vs 19.2%, P = 0.026). Incidence of NBM has not changed significantly over the last 2 decades. E. coli remains as the most common pathogen of NBM despite that GBS has increased in recent 9 years, especially in full-term infants. While all isolated GBS are susceptible to penicillin, over a third of E. coli strains are multidrug resistant due to production of ESBLs.

A Comparison of Different Strategies for Optimizing the Selection of Empiric Antibiotic Therapy for Pneumonia Caused by Gram-Negative Bacteria in Intensive Care Units: Unit-Specific Combination Antibiograms Versus Patient-Specific Risk Factors.

Guidelines suggest dual antipseudomonal therapy for empiric treatment of pneumonia caused by gram-negative bacteria in intensive care unit (ICU) patients. Additionally, consideration of local susceptibility data and patient-specific risk factors for resistance is recommended for selecting optimal empiric regimens. However, data assessing how to best do this are lacking, and it is unclear whether a local susceptibility data-based or a patient-specific risk factor-based approach will better drive appropriate empiric treatment. This study aims to compare these 2 strategies. This retrospective study was divided into 2 periods. In period I, gram-negative respiratory cultures from ICU patients were used to develop unit-specific combination antibiograms, and individual patient charts were reviewed to assess the impact of risk factors on antimicrobial susceptibility to develop a risk factor-based treatment algorithm. Optimal empiric regimens based on these 2 strategies were then defined. In period II, these regimens were hypothetically applied to patients to compare rates of appropriate empiric therapy and overuse by the 2 methods. Risk factor-based regimens had a higher appropriateness rate compared to regimens derived from antibiograms (89.9% vs 83.7%). Additionally, applying antibiogram-based regimens resulted in a higher prevalence of antibiotic overuse than a patient-specific risk factor-based approach (69.8% vs 40.3%), with excess overuse driven by a higher frequency of unnecessary use of combination therapy. Both strategies provided high rates of appropriateness in empiric antibiotic selection. However, the patient-specific risk factor-based approach demonstrated a higher rate of appropriate therapy and offered advantages in reducing rates of unnecessary combination therapy.

Correlating Climate Conditions With Pseudomonas aeruginosa Prevalence in Diabetic Foot Infections Within the United States.

The 2023 "International Working Group on the Diabetic Foot/Infectious Disease Society of America Guidelines on the Diagnosis and Treatment of Diabetes-Related Foot Infections" (DFIs) provides recommendations for Pseudomonas coverage based on the climate region. This was a retrospective national study of veterans between 1/1/2010 and 3/23/2024 with diabetes mellitus and a culture below the malleolus wound. Prevalence of Pseudomonas was categorized based on climate zones according to the International Energy Conservation Code. Multivariable logistic regression was used to determine odds ratios and 97.5% CIs. The prevalence of Pseudomonas significantly varied between US climates. Pseudomonas was most prevalent within the Hot Humid climate, where it was isolated in 11.6% of DFI cultures. Pseudomonas was least prevalent within the Very Cold climate, where it was isolated in 6.2% of cultures. In the multivariable logistic regression model, hot and humid climates were associated with an odds of P. aeruginosa of 1.92 (97.5% CI, 1.69-2.20), a hot, dry climate was associated with an odds of 1.65 (97.5% CI, 1.44-1.90), and a humid climate was associated with an odds of 1.65 (97.5% CI, 1.45-1.89). A lower Charlson Comorbidity Index, inpatient admission, recent antipseudomonal antibiotic use, and swabs were less likely to have Pseudomonas. Recent admission increased the odds of P. aeruginosa (odds ratio [OR], 1.34; 97.5% CI, 1.27-1.41). History of P. aeruginosa was associated with an increase in P. aeruginosa (OR, 8.90; 97.5% CI, 8.29-9.56). The prevalence of DFI organisms varies within different US climates. Utilization of local climate information may allow for more accurate and targeted empiric antibiotic selection when treating DFIs.

A-260 Mapping pediatric urinary tract infections: trends, prevalence and sensitivity to antimicrobials

Abstract Background Urinary tract infections (UTIs) rank among the most prevalent bacterial infections in pediatric populations, with neonates being particularly susceptible. Moreover, UTIs have a propensity for recurrence, posing ongoing health challenges. Prompt diagnosis of pediatric UTIs is crucial for timely and effective treatment, averting potential long-term complications. While clinical signs often suggest UTI diagnosis, additional tests like urinalysis and urine culture are vital to identify the causative pathogen and its antibiotic sensitivity. This study aims to quantify microorganism prevalence in positive pediatric urine tests and assess their antimicrobial resistance profiles. The purpose is, therefore, to offer scientific basis so that there is greater agility in establishing the diagnosis of UTIs in children and indicating the best antibiotic to be used empirically to prevent late consequences. Methods Between January and December 2019, a cross-sectional study was carried out with urine samples from children and adolescents collected in the database of the Clinical Analysis Laboratory of Cuiabá - MT in 2019. Only records of samples collected in the study were included in the study. laboratory of patients of both sexes, age range 1 month to 15 years. Bacterial analyzes were classified according to Gram positive, Gram negative (glucose fermenters or non-fermenters) and the sensitivity profile was standardized according to the Clinical and Laboratory Standards Institute (2019). The data were subjected to descriptive statistical analysis. Results Of the 532 positive urine samples from pediatric patients, enterobacteria were responsible for 435 (81.76%) with E. coli (64.1%) and Proteus mirabilis (15.8%) being the most isolated bacteria, in relation to Gram-positive bacteria 64 (12.03%) main bacteria was Enterococcus faecalis (81.2%) and non-glucose fermenters for 33 (6.2%) corresponding to Pseudomonas aeruginosa. E. coli, with 279 cases, was the most frequently isolated microorganism, representing (64.1%) of the cases. Females were the most affected, in 83.5% there was growth of Enterobacteria, in the Pseudomonas aeruginosa group, 51.5% of cases were female. and in Gram+ girls represented 56.2%. In those tested only for E. coli, the highest sensitivity was observed in fosfomycin (97.82%). Enterobacteriaceae showed high susceptibility to meropenem (99.8%), ertapenem (99.8%), ceftriaxone (93.8%), and ceftazidime (93.6%), but exhibited considerable resistance to sulfamethoxazole/trimethoprim (35.5%), amoxicillin (33.4%) and ampicillin (29.2%). Pseudomonas aeruginosa and gram positive bacteria were sensitive to all antibiotics tested. Conclusions The data indicate that E. coli continues to be the predominant agent in pediatric UTIs, particularly affecting females and the very young age group &amp;lt; 3 years. Regarding sensitivity profiles, bacteria were more sensitive to carbapenems and aminoglycosides. Early diagnosis is crucial to preventing long-term complications associated with UTIs in children. Consequently, this research provides a scientific basis for faster UTI diagnosis and empirical antibiotic selection in pediatrics, which may prevent late adverse outcomes.

Microbiology and Epidemiology of Orbital Cellulitis in Pediatric and Young Adult Patients.

Using data from the large and geographically diverse Military Health System (MHS) beneficiary population, we aimed to characterize and update the epidemiology and microbiology of pediatric orbital cellulitis given previous data are limited to small, single-center studies. Following institutional review board approval, we performed a retrospective analysis using the Military Health System admissions, microbiology, and pharmacy data between June 2009 and September 2019. Patients less than 22 years of age with radiological confirmation of orbital cellulitis were included. Demographic data, presence of sinusitis, advanced imaging reports, blood and wound culture results with antibiotic susceptibilities, and antibiotic prescriptions were collected. Descriptive statistics were used to summarize demographic characteristics. Imaging findings were grouped by Chandler's stage (CS), an imaging-based measure of the progressive severity of orbital involvement. A Cochran-Armitage trend test was used to evaluate the relationship between CS and likelihood of positive confirmatory culture. There was a male predominance (66.9%) and 55.5% of subjects had comorbid sinusitis. Of the 130 subjects included, 33.8% had one or more positive cultures, 30.8% had a positive wound culture, and 4.6% had a positive blood culture. The most identified organism was coagulase-negative staphylococci (23.3%), followed by Staphylococcus aureus (18.9%), Streptococcus intermedius (17.8%), and strict anaerobes as a group (13.3%). Gram-negative organisms were rare. Twenty-five percent of S. aureus were methicillin-resistant. Clindamycin resistance was identified in 9% of all S. aureus, 50% of coagulase-negative staphylococci, and 25% of S. intermedius. Clindamycin plus ceftriaxone was the most prescribed empiric antibiotic regimen (36.2%). Likelihood of a positive culture significantly increased with advancing CS. Orbital cellulitis occurs most frequently in males with sinusitis. Likelihood of positive wound culture is increased with a more advanced CS. Staphylococcus and Streptococcus spp. and anaerobes are the most identified pathogens in orbital cellulitis, while gram-negative organisms are rare. Empiric antibiotic selection should include an anti-methicillin-resistant S. aureus agent combined with a broad-spectrum beta-lactam and anaerobic coverage.

Development and external validation of a model to predict multidrug-resistant bacterial infections in patients with cirrhosis.

We included patients with cirrhosis and bacterial infections from two prospective studies: a transcontinental study was used for model development and internal validation (n = 1302), and a study from Argentina and Uruguay was used for external validation (n = 472). All predictors were measured at the time of infection. Both culture-positive and culture-negative infections were included. The model was developed using logistic regression with backward stepwise predictor selection. We externally validated the optimism-adjusted model using calibration and discrimination statistics and evaluated its clinical utility. The prevalence of MDRO infections was 19% and 22% in the development and external validation datasets, respectively. The model's predictors were sex, prior antibiotic use, type and site of infection, MELD-Na, use of vasopressors, acute-on-chronic liver failure, and interaction terms. Upon external validation, the calibration slope was 77 (95% CI .48-1.05), and the area under the ROC curve was .68 (95% CI .61-.73). The application of the model significantly changed the post-test probability of having an MDRO infection, identifying patients with nosocomial infection at very low risk (8%) and patients with community-acquired infections at significant risk (36%). This model achieved adequate performance and could be used to improve the selection of empiric antibiotics, aligning with other antibiotic stewardship program strategies.

Pyuria, bacteriuria and empirical antibiotic selection in pregnant women

Aims: In pregnancy, early diagnosis and proper treatment of urinary tract infections are crucial in preventing maternal and fetal comorbidities. Therefore, pregnant women should be screened for asymptomatic bacteriuria. This study aimed to evaluate the relationship between pyuria and bacteriuria and the susceptibility of uropathogens, as well as to review the empiric drug options for pregnant women. Methods: The presence of pyuria and bacteriuria in urine samples obtained from the pregnant outpatient clinic between January 2023 and December 2023 at Kırıkkale University Faculty of Medicine Hospital’s Infectious Diseases and Clinical Microbiology Laboratory was investigated. Uropathogens were identified and typed using the BD Phoenix™ M50 automated system for bacterial identification and antibiotic susceptibility testing, and antibiotic susceptibility was interpreted according to the European Committee on Antimicrobial Susceptibility Testing criteria. Results: A total of 1457 urine samples were evaluated in this retrospective study. Uropathogens were detected in 235 patients, while 301 samples were considered contaminated. Uropathogens were found to be susceptible to amoxicillin-clavulanate, trimethoprim-sulfamethoxazole, nitrofurantoin, and fosfomycin, in that order, for use in pregnant women. High resistance rates to third-generation cephalosporins were observed. Conclusion: According to the results of this study, local resistance rates against urinary pathogens in pregnant women should be determined at specific intervals, and empirical antibiotic therapy should be planned based on these data.

Association of empiric antibiotic selection and clinical outcomes in hospitalised children with severe orbital infections: a retrospective cohort study

ObjectiveTo determine the association of initial empiric antibiotic regimens with clinical outcomes in hospitalised children with severe orbital infections.DesignMulti-centre observational cohort study using data from 2009 to 2018 clinical records.SettingCanadian...

21 The Microbial Antibiogram as a Function of Testing Indication: Susceptibility Analysis of Escherichia coli from Symptomatic and Asymptomatic Bacteriuria Patients, 2020-2021

OBJECTIVES/GOALS: Antibiograms are used to guide empiric antibiotic selection. However, it is unclear if antibiotic profiles differ between symptomatic urinary tract infections (UTIs) and asymptomatic bacteriuria (ASB). We aimed to compare antibiotic susceptibility profiles of urinary E. coli isolates from patients with a symptomatic UTI to those with ASB. METHODS/STUDY POPULATION: We conducted a cohort study of 1,140 urinary E. coli isolates from unique patients that received care through Vanderbilt University Medical Center (VUMC) from Nov 2020 – Jun 2021. We included any patient that was seen at VUMC as an inpatient, outpatient or at the emergency department with ≥ 105 colony forming units/mL E. coli detected from a clinical urine specimen. Chart abstractions were performed to capture reported UTI symptoms and demographic information. Descriptive statistics were conducted to compare antibiotic susceptibility profiles (i.e., susceptible, intermediate, resistant) between symptomatic and ASB groups. The risk of detection of a multidrug-resistant organism (MDRO) (intermediate, or resistant to at least one antibiotic in three or more classes) was assessed between groups. RESULTS/ANTICIPATED RESULTS: Among 1,140, 1,018 (89%) and 122 (11%) were symptomatic and ASB, respectively. When comparing symptomatic and ASB, the median ages were 50 and 46. Groups had similar proportions of no indwelling catheter (94% v. 95%) and without diabetes (87% v. 88%). The collection setting between inpatient, emergency department, and outpatient were similar with most being outpatient (79% v. 83%). The proportion of patients who were pregnant, immuno compromised, or had a structural/functional urinary tract abnormality were higher in the symptomatic group. The proportion of isolates resistant and susceptible to tested antibiotics were similar between groups, with only ciprofloxacin showing slightly higher resistance among ASB (16% v. 25%). The risk of MDRO detection was similar between groups (RR: 0.858, 95% CI: 0.64, 1.15). DISCUSSION/SIGNIFICANCE: Antibiotic susceptibility comparison demonstrated similar profiles, which suggests antibiogram use as appropriate to guide ASB treatment. Results offer insight on whether traditional methods for assessing antibiotic susceptibility on population-levels could benefit from further refinement by patient-specific clinical parameters.

Antimicrobial Susceptibility Patterns in Adult Patients Hospitalized for Community-Acquired Urinary Tract Infections in Two Tertiary Hospitals in Santiago, Chile

The constant increase of factors associated with the presence of resistant strains, makes empirical antibiotic selection a challenge in patients hospitalized for community-acquired urinary tract infection. We characterized the bacteria and their antimicrobial susceptibility pattern in cultures obtained from adult patients that needed hospitalization for this disease in two tertiary hospitals in Santiago, Chile. We conducted a prospective cross-sectional study in adults hospitalized for community-acquired urinary tract infection between 2017 and 2022. All patients with positive urine cultures were included in the analysis. A total of 830 patients were included. Escherichia coli was the most frequent infectious agent (68.1%), followed by Klebsiella spp. (17.7%) and Enterococcus faecalis (6.7%). Among Enterobacteriaceae strains, 35.2%, 19.7% and 27.2% were resistant to first, second and third-generation cephalosporin, respectively. 36.9% were resistant to ciprofloxacin and 1.8% to amikacin. Gram-positive bacteria were resistant to oxacillin and ampicillin in 25% and 18%, respectively. We detected a high prevalence of community-acquired urinary tract infections caused by bacteria resistant to commonly used antibiotics in adult patients that need to be hospitalized.

Application of the Weighted-Incidence Syndromic Combination Antibiogram (WISCA) to guide the empiric antibiotic treatment of febrile neutropenia in oncological paediatric patients: experience from two paediatric hospitals in Northern Italy

BackgroundGuidelines about febrile neutropenia in paediatric patients are not homogeneous; the best empiric treatment of this condition should be driven by local epidemiology. The Weighted-Incidence Syndromic Combination Antibiogram (WISCA) addresses the need for disease-specific local susceptibility evidence that could guide empiric antibiotic prescriptions based on outcome estimates of treatment regimens obtained as a weighted average of pathogen susceptibilities. This study developed a WISCA model to inform empirical antibiotic regimen selection for febrile neutropenia (FN) episodes in onco-haematological paediatric patients treated at two Italian paediatric tertiary centres.MethodsWe included blood cultures from patients with a bloodstream infection and neutropenia admitted to the Paediatric Haematology-Oncology wards in Padua and Genoa Hospitals from 2016 to 2021. WISCAs were developed by estimating the coverage of 20 antibiotics as monotherapy and of 21 combined regimens with a Bayesian probability distribution.ResultsWe collected 350 blood cultures, including 196 g-negative and 154 g-positive bacteria. Considering the most used antibiotic combinations, such as piperacillin–tazobactam plus amikacin, the median coverage for the pool of bacteria collected in the study was 78%. When adding a glycopeptide, the median coverage increased to 89%, while the replacement of piperacillin–tazobactam with meropenem did not provide benefits. The developed WISCAs showed that no monotherapy offered an adequate coverage rate for the identified pathogens.ConclusionsThe application of WISCA offers the possibility of maximizing the clinical utility of microbiological surveillance data derived from large hospitals to inform the choice of the best empiric treatment while contributing to spare broad-spectrum antibiotics.

Microbiology and Antimicrobial Susceptibility in Adult Dacryocystitis.

To investigate the microbiology and antimicrobial susceptibility of dacryocystitis in adults and identify the changing trends over time in Taiwan. This is a single-centered, retrospective study. We retrospectively reviewed adult patients with dacryocystitis from January 2012 to December 2021 in a tertiary medical center in Taiwan. The pathogens and in vitro antimicrobial susceptibility of the pus cultures from the lacrimal sac were collected. Thirty-five cultures in acute and 211 cultures in chronic dacryocystitis were collected. Of the 220 isolates, a similar proportion of gram-positive (44%) and gram-negative (43%) aerobes were demonstrated in chronic dacryocystitis and more gram-negative aerobes (50%) than gram-positive aereobes (41%) in acute dacryocystitis. The most common pathogens were methicillin-resistant Staphylococcus aureus (MRSA; 28.1%) and Pseudomonas aeruginosa (28.1%) in acute dacryocystitis, while coagulase-negative Staphylococci was the most common micro-organism in chronic dacryocystitis. The effective antibiotics for gram-positive aerobes were vancomycin (100%), moxifloxacin (88%) and trimethoprim/sulfamethoxazole (78%). Meropenem (95%), amikacin (93%), and levofloxacin (91%) were sensitive to more than 90% of gram-negative aerobes in current study. High resistant species were also isolated in our cohort. More gram-negative pathogens and more resistant species are rising in adult dacryocystitis. Understanding the bacteriology and antimicrobial susceptibility of the region is crucial for the empirical antibiotic selection in clinical practice.

Microbiological profile and antibiotic susceptibility profile of urine cultures in patients with spinal cord injury-retrospective study.

Urinary tract infections (UTIs) and urinary tract colonizations (UTCs) are common in patients with spinal cord injury (SCI). The aim of this study was to characterize the microbiological profile of urine cultures in patients with SCI and to determine the antibiotic susceptibility profile of most common microorganisms, to track antibiotic resistance and facilitate empiric antibiotic selection. A retrospective observational study was conducted on 235 urine culture results of 29 patients with SCI followed at a Physical and Rehabilitation Medicine outpatient consultation between January 2016 and April 2024. Data regarding sociodemographics, cause of SCI, American Spinal Injury Association Impairment Scale classification, voiding method, microbiological urine culture profile, and antimicrobial resistance were collected and statistically analyzed. UTIs (defined as bacteriuria, leukocyturia, positive urine culture, and new onset of signs and/or symptoms) were differentiated from UTCs. Patients were mostly men (86%), with a mean age of 52.1 years. UTIs occurred in 134 specimens (57%) and UTCs in 101 (43%). In both UTIs and UTCs, microbiological agents were mostly bacteria; Escherichia coli was the commonest overall (39%) and more frequent in indwelling catheterization (in UTIs) and intermittent self-catheterization (in UTCs); more frequently identified microorganisms were E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Enterococcus faecalis. For these 5 more frequent bacteria, antibiotic susceptibility profiles were determined. High resistance to fluoroquinolones, low resistance to cephalosporins, and very low resistance to nitrofurantoin were found. Specific multidrug-resistant organisms (MDROs) accounted for 11.2%, mostly identified in patients with indwelling catheters. Antibiotic prescriptions in UTIs were according to antibiograms. In UTIs and UTCs, E. coli was the most common microorganism; microorganisms were distinct on different types of voiding methods. Antibiotic susceptibility profiles were determined for the more frequent bacteria. Very low resistance to nitrofurantoin of E. coli and E. faecalis, low resistance to cephalosporins, and high resistance to fluoroquinolones were found. The data now reported can, in selected cases, facilitate empiric antibiotic selection.

Bacteriological Profile and Antimicrobial Resistance Patterns in Pediatric Urinary Tract Infections: A Cross-Sectional Study at Dhaka Shishu Hospital

Background: Urinary tract infections (UTIs) are a prevalent concern in pediatric healthcare, causing distress to children, raising parental concerns, and potentially leading to lasting kidney damage. The highest incidence of first-time symptomatic UTIs occurs in infants during the first year of life, with a subsequent marked decrease. Febrile infants under 2 months, presenting with unexplained fever, constitute a critical subset requiring particular attention. Knowledge of the bacteriological profile and antimicrobial resistance patterns in specific regions is crucial for guiding effective treatment strategies. Methods: A cross-sectional study was conducted at 250 Bedded General Hospital, Jamalpur, Bangladesh from Feb 2016 to Aug 2016 to assess the bacteriological profile and antibiotic resistance patterns in pediatric UTIs. A total of 147 culture-positive UTI patients were included. Bacterial isolates were identified, and colony counts for samples with ≥105 CFU/mL bacteria were considered positive. Antimicrobial susceptibility testing was performed using twelve agents, and resistance patterns were analyzed. Results: Among the 147 culture-positive UTI patients, Escherichia coli (E-coli) was the predominant isolate (70%), followed by Klebsiella spp. (13.6%), Pseudomonas (5.44%), Enterobacter spp (3.40%), Staphylococcus Aureus (3.40%), Proteus (2.72%), and Enterococcus (1.36%). Antimicrobial resistance analysis revealed varying patterns, with Cefradine (79.59%), Co-trimoxazole (SXT) (69.39%), Nalidixic acid (NA) (66.67%), and Ceftazidime (CTM) (48.98%) showing higher resistance rates. No drug exhibited 100% resistance against urinary pathogens, indicating a dynamic resistance landscape. Conclusion: This study highlights the importance of understanding local prevalence and resistance patterns in guiding empirical antibiotic selection for pediatric UTIs. The observed decrease in antimicrobial resistance underscores the need for continuous surveillance and tailored antibiotic strategies. Clinicians should base their treatment decisions on the specific epidemiological context rather than relying solely on universal or national guidelines.