Infection and Drug Resistance最新文献

Introduction: Salmonella, a leading cause of human infectious diarrhea diseases, foodborne illness, and zoonotic infections, poses a significant health burden.

Methods: A retrospective screening was performed to elucidate the serotype distribution and antimicrobial resistance of 933 human Salmonella isolates from nine cities (prefectures) in Guizhou province of southwestern China between 2019 and 2023 through slide agglutination and antimicrobial resistance testing.

Results: Fifty-four different serotypes were identified in this study, with S. Typhimurium (44.4%) and S. Enteritidis (20.7%) being the predominant serotypes, followed by S. London (3.1%), S. Derby (2.8%), and S. Rissen (2.0%). A total of 39 serotypes were reported for the first time in Guizhou province, and 121 isolates (13.0%) could not be classified. The diversity of Salmonella serotypes in Guizhou has increased from 8 in 2019 to 39 in 2023. In addition, the detection rate of S. Enteritidis showed a decreasing trend over time, while the detection rate of S. Typhimurium demonstrated an annual increase since 2020. For 933 isolates, a significant majority (94.0%) exhibited resistance to at least one class of antimicrobial agents. The highest resistance observed was to ampicillin (86.4%), followed by resistance to tetracycline (76.3%) and streptomycin (72.8%). Notably, we discovered that the resistance rate to colistin was 4.7%, with 93.2% of these isolates being S. Enteritidis. Meanwhile, 78.5% of isolates were demonstrated multidrug resistance (MDR), with the MDR rates for S. Rissen and S. Typhimurium exceeding 90%. Additionally, 5.7% of Salmonella isolates were extensively drug-resistant (XDR), with S. Typhimurium and S. Enteritidis exhibiting XDR rates of 5.1% and 4.1%, respectively. The rate of MDR and XDR in Salmonella peaked in 2019 and then gradually declined from 2020 to 2022, rising again in 2023.

Conclusion: Our research revealed an increasing diversity in Salmonella serotypes within Guizhou province, alongside significant challenges posed by MDR and a rising XDR rate. Therefore, it is essential to continuously improve the surveillance of Salmonella, keep track of changes in serotype distribution and dynamic shifts, and strengthen the persistent monitoring of antimicrobial agents.

Purpose: This study aimed to describe the population pharmacokinetics (PopPK) of ceftazidime-avibactam (CAZ-AVI) in adult patients, and to develop optimal dosing regimens for both non-critically ill and critically ill patients by combining different pharmacokinetic/pharmacodynamic (PK/PD) targets.

Patients and methods: A prospective, single-center study involving patients who were infected with CRKP and received CAZ-AVI therapy was conducted. Nonlinear mixed-effect modeling was used to develop a PopPK model. The optimal dosing regimen was assessed using Monte Carlo simulation.

Results: The PopPK analysis of CAZ-AVI included 91 steady-state concentrations from 45 adult patients. The data were modeled using a one-compartment model. The typical population values of CAZ and AVI clearances were 2.96 L/h and 3.09 L/h, and the volumes of distribution were 17.76 L and 18.25 L, respectively. Our study showed that creatinine clearance (CrCL) calculated using the Cockcroft-Gault equation significantly affected the pharmacokinetics of CAZ-AVI. The Monte Carlo simulation optimized the dosing regimen for both non-critically ill and critically ill patients with varying renal functions, providing detailed supplements to the instructions.

Conclusion: Our study established a PopPK model for CAZ-AVI and proposed a reference for dosing regimen adjustment based on the severity of the disease and renal functional status.

Objective: Pseudomonas aeruginosa (P. aeruginosa) is a gram-negative opportunistic pathogen, which can cause acute and chronic infections, often resulting in high mortality. The aim of this study was to investigate the risk factors for the development and mortality of patients with carbapenem-resistant P. aeruginosa bloodstream infection (CRPA BSI).

Methods: A total of 112 patients with CRPA BSI and 112 patients with carbapenem-sensitive P. aeruginosa (CSPA) BSI were included from a Chinese teaching hospital from January 2017 to December 2023 in this retrospective cohort study. The detection rate, antimicrobial susceptibility of P. aeruginosa and clinical characteristics of these patients were investigated. Multivariable logistic regression analysis was used to identify risk factors for the development and outcomes of CRPA BSI.

Results: In the past 7 years, 7480 blood samples of P. aeruginosa were cultured in the hospital. The detection rates of CRPA, multidrug resistant P. aeruginosa (MDRPA), and difficult-to-treat resistant P. aeruginosa (DTRPA) BSI increased annually (26% to 47%, 10% to 36% and 5% to 15%, respectively). CRPA showed high resistance to conventional antibiotics. Chronic lung disease (OR 3.953, 95% CI 1.131-13.812), transplantation (OR 2.837, 95% CI 1.036-7.770), multi-organ failure (OR 4.815, 95% CI 1.949-11.894), pre-infection within CRPA (OR 9.239, 95% CI 3.441-24.803), and exposure to carbapenems within 90 days (OR 2.734, 95% CI 1.052 -7.106) were independent risk factors for the development of CRPA bacteremia. Sepsis or septic shock (OR 8.774, 95% CI 3.140-24.515, p = 0.001) were independent risk factors of mortality.

Conclusion: Chronic lung disease, transplantation, multi-organ failure, prior CRPA infection, and prior carbapenems exposure are independent risk factors for the development of CRPA bacteremia. Sepsis or septic shock increases 28-day mortality. To investigate the molecular mechanisms of carbapenem-resistance of P. aeruginosa, standardize antibiotic usage, and assess risk factors for the development and mortality of CRPA BSI are beneficial to control infection and reduce death.

Background: Mycoplasma pneumoniae pneumonia (MPP) is a prevalent disease among children. Typically, macrolides are the first-line treatment for MPP in China. However, the number of cases resistant to macrolides has been rising, especially after the outbreak of the COVID-19 pandemic, which has further complicated the clinical management of macrolide-unresponsive Mycoplasma pneumoniae pneumonia (MUMPP) in children.

Objective: This study examined the clinical characteristics of MUMPP and the effects of various treatments on children with MUMPP during March 2023 to February 2024 in southern China.

Methods: We conducted a retrospective case-control study at a university-affiliated hospital in southern China. Patients were categorized based on their response to macrolide treatment into two groups: MUMPP and control group. The study included 549 pediatric patients. Of these, 297 were in the MUMPP group and 252 were in the control group. This categorization allowed us to compare clinical characteristics and laboratory indicators between the groups. The MUMPP group received one of the three treatments: combined antibiotics, additional steroids, or a switch to doxycycline. Subsequently, we analyzed differences in clinical outcomes, which included hospital stay, hospital cost, and recovery time.

Results: No significant differences were found in gender or pre-admission disease duration between the MUMPP and control group (P>0.05). However, subjects in MUMPP group was older, had longer fever durations, extended hospital stays, higher medical costs, and elevated levels of C-reactive protein, lactate dehydrogenase, IL-6, and γ-IFN. All of which showed statistically significant differences (P<0.05). Within the MUMPP group, patients switched to doxycycline had the shortest hospital stay and recovery time, significantly differing from those in other treatment groups (P<0.05).

Conclusion: Children in the MUMPP group exhibited higher inflammatory indicators than the control group. The early adaptation of treatment strategies, particularly the switch to doxycycline, is associated with improved clinical outcomes.

Background: Multidrug-resistant Gram-negative bacteria (MRGN) pose a significant threat and require priority attention. Polymyxin B (PMB) retains substantial activity against MRGN and makes it potentially the last resort therapy for MRGN infections in children. To assess the effectiveness and safety of PMB in treating MRGN infections in Chinese children.

Methods: Paediatric patients aged 0-18 years who were treated with PMB for MRGN infections were enrolled in the study. These cases were then compared with those identified in a literature review. In logistic regression, three independent variables were used for analyzing clinical effectiveness, and two for nephrotoxicity.

Results: A cohort of 54 children was included in study and 24 eligible literature of 259 children were included in literature review. Out of the 54 patients, 53.7% showed favorable clinical responses, while 13.0% died during their hospitalization, of which 3.7% died within 30 days after receiving PMB. AKI was observed in 25.9% patients with 11.1% risk stage, 7.4% injury stage and 7.4% failure stage. The PMB co-administration with carbapenems was associated with significantly higher effectiveness (odds rate [OR] = 3.16, 95% confidence interval [CI]: 1.02-9.86, P = 0.05) and co-administration with potent diuretic (furosemide) may increase the risk of AKI (OR = 4.91, 95% CI: 0.96-24.98, P = 0.05).

Conclusion: PMB has advantages in treating MRGN infections in paediatric patients, showing favorable clinical responses and pathogen clearance. AKI is a notable safety concern. The small sample size might hinder reliable identification of factors affecting clinical effectiveness and adverse effects.

Introduction: The diagnostic utility of pleural fluid C-reactive protein (CRP) and procalcitonin (PCT) for parapneumonic pleural effusion (PPE) is a subject of ongoing investigation. There remains lack studies comparing their diagnostic accuracy in a head-to-head manner. Furthermore, the incremental diagnostic value of their combination over a single marker and the net benefit of them remains unknown.

Methods: This prospective study enrolled participants presenting with undiagnosed pleural effusion, subsequently measuring their pleural levels of CRP and PCT. A diagnostic model that integrated both biomarkers was constructed using logistic regression analysis. The diagnostic performance and net benefit of CRP, PCT, and the composite model were assessed through receiver-operating characteristic (ROC) curve analysis and decision curve analysis (DCA).

Results: The study included 32 PPE patients and 121 patients without PPE. The area under the ROC curve (AUC) for CRP was 0.73 (95% confidence interval [CI]: 0.63-0.83), with a sensitivity of 0.71 (95% CI: 0.55-0.87) and a specificity of 0.68 (95% CI: 0.59-0.77) at a threshold of 10 mg/L. In contrast, the AUC for PCT was 0.58 (95% CI: 0.46-0.69), with sensitivity and specificity rates of 0.50 (95% CI: 0.33-0.67) and 0.65 (95% CI: 0.56-0.74) at a threshold of 0.1 ng/mL, respectively. Notably, the AUC for the diagnostic model was comparable to that of CRP alone at 0.73 (95% CI: 0.63-0.82). DCA showed that applying CRP provided a net clinical benefit, while PCT did not.

Conclusion: Pleural fluid CRP possesses moderate diagnostic capability for PPE, while PCT exhibits limited diagnostic utility. Additionally, the combined application of CRP and PCT does not confer any significant enhancement in diagnostic accuracy over the use of CRP alone.

Background: The rapid and accurate identification of infectious pathogens in HIV-infected patients remains a challenge. Metagenomic next-generation sequencing (mNGS) is a panpathogen assay for rapid diagnosis of infectious diseases. Here, the diagnostic value of mNGS was evaluated in HIV-infected patients and compared with conventional microbiological tests (CMTs).

Methods: This study was conducted on 216 hIV-infected patients with suspected opportunistic infections. Infectious pathogen detection was done by mNGS and conventional microbiological tests, respectively.

Results: A total of 195 patients (90.2%) were positive for microbial pathogens by mNGS, while 135 patients (62.5%) were positive for microbial pathogens by CMTs. Mixed infection was identified in 92 patients by mNGS, and 41 patients were detected with mixed infection by CMTs. Fungi and virus mixed infection was the most frequent pattern detected by mNGS (32, 14.8%) and CMTs (22, 10.2%). The CD4+ T cell count in patients with mixed pathogens was significantly lower than that in patients infected with a single pathogen. Pathogens were quickly identified by mNGS in 151 patients (69.9%), and appropriate treatments were initiated. In 47 patients antibacterial agents were adjusted based on mNGS results, in 39 patients antifungal agents were changed, and 35 patients had antiviral agents added.

Conclusion: mNGS is a valuable tool and enhances rapid microbiological identification in HIV-infected patients. Combined with CMTs, mNGS may facilitate personalized antimicrobial treatment strategies and increase survival.

Introduction: Acute-on-chronic liver failure (ACLF) is a severe syndrome that manifests as acute liver function deterioration and organ failure. Coinfection with invasive pulmonary aspergillosis (IPA) in ACLF patients is characterized by high mortality and increasing morbidity. The aim of this study was to explore the early warning factors and prognosis of ACLF patients with IPA coinfection.

Methods: In this retrospective study, we collected clinical, biochemical, and microbiological data from patients with ACLF and IPA from May 2019 to May 2023. Univariable and multivariate analyses were used to identify independent risk factors for IPA in ACLF patients. Moreover, the area under the curve (AUC) and decision curve analysis (DCA) were used to evaluate the model performance.

Results: A total of 438 patients with ACLF were enrolled, 408 (93.2%) non-IPA patients and 30 IPA (6.8%) including 29 probable cases and one proven case. The 28-day case fatality rate (56.7% vs 29.4%) was higher in ACLF patients with IPA than in ACLF patients without IPA, but without statistical difference. Multivariate analysis revealed that early warning factors for IPA coinfection in ACLF patients included nausea (p = 0.010), expectoration (p < 0.001), bacterial and fungal infections (p < 0.001), corticosteroid use (p = 0.037), surgery (p = 0.081), haemoptysis (p = 0.015) and increased leukocyte counts (p = 0.010). The AUC was 0.934 (p < 0.001), and DCA verified the validity and clinical effectiveness of our model.

Conclusion: These findings provide valuable insights for clinicians in the early diagnosis of IPA in ACLF patients and may facilitate timely intervention and treatment.

Chlamydia psittaci is one of the primary pathogens responsible for community-acquired atypical pneumonia. If not treated promptly, it can progress to severe pneumonia and may lead to multiple organ dysfunction as well as secondary infections with multi-drug-resistant (MDR) bacteria. Omadacycline, a novel aminomethylcycline antibiotic derived from tetracycline, exhibits high activity against various bacterial strains. This case report describes a patient who developed severe pneumonia caused by Chlamydia psittaci in conjunction with a MDR bacterial infection. Despite initial treatment with moxifloxacin and doxycycline, the patient experienced treatment failure. The patient's condition deteriorated, presenting complications such as progressive infection, leukopenia, liver dysfunction, electrolyte imbalances, and respiratory alkalosis. Following the adjustment to omadacycline therapy for 48 hours, all complications were rapidly alleviated, leading to successful treatment of the patient.

Introduction: The inappropriate prescribing and use of antibiotics have contributed to the emergence and spread of antimicrobial resistance (AMR). In Zambia, there is a paucity of information on the prescribing patterns and use of antibiotics among hospitalized patients in level 1 hospitals. This study investigated antibiotic use in five level 1 hospitals in Lusaka, Zambia.

Methods: This cross-sectional study utilized the World Health Organization (WHO) Point Prevalence Survey (PPS) methodology among in-patients admitted in level 1 hospitals before 08:00 a.m. on the survey day in August 2024. Data were analysed using IBM SPSS version 23.0.

Results: The prevalence of antibiotic use among inpatients was 59.0%, with ceftriaxone being the most prescribed. Antibiotics were prescribed mainly for paediatrics and male inpatients. This study found that 53.0% of prescribed antibiotics were from the Access group while 38.2% were from the Watch group of the World Health Organization Access, Watch, and Reserve (AWaRe) classification. Adherence to national treatment guidelines was 36.0%, with most antibiotics prescribed empirically without evidence of culture and sensitivity tests.

Conclusion: This study found a high use of antibiotics and low adherence to treatment guidelines in level 1 hospitals in Lusaka, Zambia. The findings of this study demonstrate the need to establish and strengthen antimicrobial stewardship programs and strengthen laboratory capacity to aid clinicians in diagnosing, treating, and managing patients across level 1 hospitals in Zambia.