Multidrug-resistant Gram-negative bacterial infections and associated factors in a Kenyan intensive care unit: a cross-sectional study

Development and validation of a nomogram-based risk prediction model for carbapenem-resistant Klebsiella pneumoniae in hospitalized patients

Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses one of the major challenges in clinical anti-infective therapy worldwide. This retrospective cohort study at a tertiary general hospital in Wuhan aimed to identify risk factors for hospital-acquired CRKP infections among 1,113 patients. All participants were aged 18 years and above, and had confirmed positive cultures for KP isolated within 48 hours post-hospitalization. Independent risk factors were identified using LASSO logistic regression and incorporated into a predictive nomogram. The factors included in the nomogram were prior carbapenem exposure, prior β-lactams-β-lactamase inhibitor combination (BLBLI) exposure, prior intensive care unit (ICU) stay, and prior mechanical ventilation. The areas under the receiver operating characteristic curve (AUC) for the nomogram were 0.793 in the training group (70% of patients) and 0.788 in the validation group (30% of patients), demonstrating its discriminatory power and predictive accuracy. The P values for the Hosmer-Lemeshow test were 0.333 and 0.684, indicating good calibration. The clinical utility of the nomogram was further supported by decision curve analysis (DCA) and clinical impact curve (CIC), demonstrating its potential to guide clinical decision-making. Our retrospective analysis identified key risk factors for CRKP infection and developed a nomogram that could effectively predict CRKP infections in hospitalized patients. Although the single-center nature of this study limits generalizability, the nomogram provides a foundation for future prospective, multicenter validations.IMPORTANCEWe established a nomogram scoring system that incorporates four key risk factors: prior carbapenem exposure, prior β-lactams-β-lactamase inhibitor combination (BLBLI) exposure, prior intensive care unit (ICU) stay, and prior mechanical ventilation. This nomogram demonstrated strong discriminatory power, excellent calibration, and significant clinical utility. This study highlights the critical risk factors associated with hospital-acquired carbapenem-resistant Klebsiella pneumoniae (CRKP) infections, providing valuable insights for clinicians to identify high-risk patients.

Effects of tea tree oil and cefepime treatments on morphological, genetic, histopathological, immunohistochemistry, and biochemical assessments in liver and kidney of Escherichia coli infected rats

The current study evaluated the influence of the treatment with tea tree oil and cefepime on morpho- genetic, histo-immunohistochemical, and biochemical assessments in rats experimentally challenged with Escherichia coli ATCC 4157™. Thirty adult male rats were divided into control, E. coli infected positive group (1×108CFU/I/P/once), E. coli with cefepime-supplemented group (45 mg/kg bw/I/M/day), E. coli with tea tree oil treated group (1.5 ml/per os/day), and the E. coli-challenged group that received a combination of tea tree oil and cefepime. E. coli infection induced morphological changes in color and texture of both liver and kidney. The transcription levels of the PHLPP2 and Nrf2 genes were noticeably lowered in all treated groups related to the E. coli group. Regarding the TLR4 expression, it was clearly up-regulated in the E. coli group in comparison to other groups, while CD14 gene decreased clearly in all treated groups compared to the positive group. The findings revealed that RBC, HGB, and PCV were clearly higher in the positive group compared to all treated groups. AST, ALT, and ALP, total bilirubin and its fractions, urea, and creatinine maximized in the positive group and decreased by the treatment, especially in the E+CF+oil treated group. Regarding the redox balance, MDA levels of MDA were notably reduced in the E+CF+oil treated group compared to the positive and the other treated groups. GSH, SOD, and GPX were significantly induced in the E. coil-treated group and decreased significantly with treatment. Overall, cefepime is highly safe especially when dually supplied with tea tree oil for mitigating E. coli adverse impact.

Multidrug-Resistant Bacteria in Immunocompromised Patients

The increasing incidence of antibiotic resistance in bacteria is a major problem in terms of therapeutic options, especially in immunocompromised patients, such as patients from intensive care units (ICUs), HIV-positive patients, patients with malignancies or transplant patients. Commensal bacteria, especially anaerobes, serve to maintain microbial stability by preventing overpopulation with pathogenic bacteria. In immunocompromised patients, microbiota imbalance caused by antibiotic therapy and decreased host immunity favors intestinal overpopulation with pathogenic species, leading to increased bacterial translocation and susceptibility to systemic infections. Infections with multidrug-resistant (MDR) bacteria pose major challenges to the establishment of appropriate treatment and lead to increased mortality. Asymptomatic colonization with MDR bacteria usually precedes infection and tends to persist for long periods of time, and in immunocompromised patients, colonization with MDR bacteria is a risk factor for systemic infections. This review aims to assess the relation between colonization and infection with MDR bacteria in immunocompromised patients such as ICU patients, HIV-positive patients and cancer patients and to identify the prevalence and patterns of MDR bacterial colonization and infection in this category of patients.

Distribution Patterns and Antibiotic Resistance Profiles of Bacterial Pathogens Among Patients with Wound Infections in the Jiaxing Region from 2021 to 2023

Purpose

To systematically assess the distribution and antimicrobial susceptibility of pathogens in wound infections, and analyze risk factors associated with multidrug resistance (MDR).

Patients and Methods

Retrospectively analyzing Jiaxing-region medical records between January 2021 and December 2023, we identified a cohort of 461 wound infection patients. Cultures were grown on various agars, with bacteria identified via Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. The antimicrobial susceptibility of the organisms were conducted by VITEK 2 system, Kirby-Bauer disk diffusion method and Epsilometer test. Statistical Package for the Social Sciences (SPSS) version 22 was used for statistical analysis. Multivariable logistic regression models were developed to pinpoint risk factors for multidrug-resistant organism (MDRO) infections and predict occurrences.

Results

From 461 patients, 549 bacterial pathogens were isolated, predominantly consisting of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Enterobacter cloacae, and Enterococcus faecalis. Vancomycin, linezolid, and tigecycline maintained their efficacy against Staphylococcus aureus and Enterococcus species, while Pseudomonas aeruginosa demonstrated sensitivity to aminoglycosides. Conversely, Escherichia coli exhibited high amoxicillin resistance (85.4%). More than half of the isolates were resistant to levofloxacin, ceftriaxone, cotrimoxazole, and gentamicin, with Acinetobacter baumannii strains showing considerable resistance (65.8-68.4%) to advanced cephalosporins and carbapenems. Within this group, 58 MDROs were detected, primarily originating from Burn Plastic Surgery, Emergency, and Intensive Care Unit (ICU) departments. Multivariate logistic regression identified hyperglycemia, hypoalbuminemia, surgery, extended hospitalization, and exposure to multiple antibiotic classes as independent risk factors for MDRO wound infections. Based on these findings, a predictive model for MDRO occurrence in wounds was constructed, which had a sensitivity of 0.627, specificity of 0.933, and an Area Under the Curve (AUC) of 0.838.

Conclusion

Staphylococcus aureus and Pseudomonas aeruginosa dominated in wound infections with differential antibiotic resistance. Independent risk factors included hyperglycemia, hypoalbuminemia, surgery, extended hospitalization, and polyantibiotic use. We urge prioritizing culture, susceptibility tests, and personalized antibiotic strategies to address MDRO risks and improve wound infection management specificity and efficacy.

Carbapenem-resistant gram-negative bacterial infections and risk factors for acquisition in a Kenyan intensive care unit

BACKGROUND

Carbapenem-resistant Gram-negative bacteria (CR-GNB) are a critical public health threat globally; however, there are inadequate surveillance data, especially in intensive care units (ICU), to inform infection prevention and control in many resource-constrained settings. Here, we assessed the prevalence of CR-GNB infections and risk factors for acquisition in a Kenyan ICU.

METHODS

A hospital-based cross-sectional study design was adopted, recruiting 162 patients clinically presenting with bacterial infection after 48 h of ICU admission, from January to October 2022 at the Nairobi West Hospital, Kenya. Demographics and clinical data were collected by case report form. The type of sample collected, including blood, tracheal aspirate, ascitic tap, urine, stool, and sputum depended on the patient's clinical presentation and were transported to the hospital Microbiology laboratory in a cool box for processing within 2 h. The samples were analyzed by cultured and BD Phoenix system used for isolates' identity and antimicrobial susceptibility.

RESULTS

CR-GNB infections prevalence was 25.9% (42/162), with Klebsiella pneumoniae (35.7%, 15/42) and Pseudomonas aeruginosa (26.2%, 11/42) predominating. All isolates were multidrug-resistant (MDR). P. aeruginosa and A. baumannii were 100% colistin-resistant, while K. pneumoniae (33.3%) was tigecycline-resistant. History of antibiotics (aOR = 3.40, p = 0.005) and nasogastric tube (NGT) use (aOR = 5.84, p = < 0.001) were the risk factors for infection.

CONCLUSION

Our study highlights high MDR- and CR-GNB infections in ICU, with prior antibiotic exposure and NGT use as risk factors, and diminishing clinical value of colistin and tigecycline. In this study setting and beyond, strict implementation of antimicrobial stewardship programs and adherence to infection prevention and control through monitoring, evaluation and feedback are warranted to curb CR-GNB infections, especially among the risk groups.

Impact of Beta-Lactam Target Attainment on Resistance Development in Patients with Gram-Negative Infections

BACKGROUND

The objective was to identify associations between beta-lactam pharmacokinetic/pharmacodynamic (PK/PD) targets and Gram-negative bacteria resistance emergence in patients.

METHODS

Retrospective data were collected between 2016 to 2019 at the University of Florida Health-Shands Hospital in Gainesville, FL. Adult patients with two Gram-negative isolates receiving cefepime, meropenem, or piperacillin-tazobactam and who had plasma beta-lactam concentrations were included. Beta-lactam exposures and time free drug concentrations that exceeded minimum inhibitory concentrations (ƒT > MIC), four multiples of MIC (ƒT > 4× MIC), and free area under the time concentration curve to MIC (ƒAUC/MIC) were generated. Resistance emergence was defined as any increase in MIC or two-fold increase in MIC. Multiple regression analysis assessed the PK/PD parameter impact on resistance emergence.

RESULTS

Two hundred fifty-six patients with 628 isolates were included. The median age was 58 years, and 59% were males. Cefepime was the most common beta-lactam (65%) and Pseudomonas aeruginosa the most common isolate (43%). The mean daily ƒAUC/MIC ≥ 494 was associated with any increase in MIC (p = 0.002) and two-fold increase in MIC (p = 0.004). The daily ƒAUC/MIC ≥ 494 was associated with decreased time on antibiotics (p = 0.008). P. aeruginosa was associated with any increase in MIC (OR: 6.41, 95% CI [3.34-12.28]) or 2× increase in MIC (7.08, 95% CI [3.56-14.07]).

CONCLUSIONS

ƒAUC/MIC ≥ 494 may be associated with decreased Gram-negative resistance emergence.