Enterobacteriaceae resistant to third generation cephalosporins upon hospital admission: risk factors and clinical outcomes

Antibiotic prescribing patterns and carriage of antibiotic-resistant Escherichia coli and Enterococcus species in healthy individuals from selected communities in Lusaka and Ndola districts, Zambia

Objectives

This study assessed antibiotic prescribing patterns in primary healthcare facilities and antimicrobial resistance (AMR) profiles of commensal Escherichia coli and enterococci isolated from pregnant women and children under 5 years of age.

Materials and methods

This cross-sectional study was conducted in Lusaka and Ndola districts of Zambia. Prescription pattern data were obtained from hospital pharmacies. Identification and antimicrobial susceptibility profiles of E. coli and enterococci were determined by conventional methods, while confirmation of both pathogens and AMR genes were determined by PCR. Data were analysed using WHONET and SPSS version 25.0.

Results

Most prescribed antibiotics at the primary healthcare facilities belonged to the Access group of the WHO Access, Watch and Reserve (AWaRe) classification. All the primary healthcare facilities adhered to the AWaRe framework of ≥60% prescribed antibiotics belonging to the Access group. However, resistance was highest in the Access group of antibiotics. E. coli resistance to ampicillin ranged from 71% to 77% and to co-trimoxazole from 74% to 80%, while enterococcal resistance to tetracycline was 59%-64%. MDR was highest in E. coli (75%) isolates, while XDR was highest in enterococcal isolates (97%). The identified AMR genes in E. coli included blaCTX-M, sul2 and qnrA, while those of enterococci included erm(B), erm(C) and erm(A).

Conclusions

Resistance was highest in the prescribed WHO Access group of antibiotics. These findings highlight the need to use local susceptibility data to formulate country-specific treatment guidelines in line with WHO AWaRe classification and enforce regulations that prohibit easy access to antibiotics.

The Resistance Mechanisms and Clinical Impact of Resistance to the Third Generation Cephalosporins in Species of Enterobacter cloacae Complex in Taiwan

Enterobacter cloacae complex (ECC) is ubiquitous in the environment and is an important pathogen causing nosocomial infections. Because routine methods used in clinical laboratories cannot identify species within ECC, the clinical significance of each species within ECC is less known. We applied hsp60 gene sequencing to identify the species/clusters of ECC and detected β-lactamase genes and class 1 integrons with PCR for 184 clinical ECC isolates in Taiwan from 2013 to 2014 to investigate the clinical impact of species within ECC. The four most common clusters were E. hormaechei subsp. steigerwaltii (cluster VIII) (29.9%), E. hormaechei subsp. oharae (cluster VI) (20.1%), E. cloacae subsp. cloacae (cluster XI) (12%), and E. kobei (cluster II) (10.3%). E. hormaechei, which consisted of four clusters (clusters III, VI, VII, and VIII), is the predominant species and accounted for 57.1% of the isolates. The ceftazidime resistance rate was 27.2%, and the ceftriaxone resistance rate was 29.3%. Resistance to third generation cephalosporin was associated with a higher 30-day mortality rate. In total, 5 (2.7%), 24 (13.0%), and 1 (0.5%) isolates carried ESBL, AmpC, and carbapenemase genes, respectively. Class 1 integrons were present in 24.5% of the isolates, and most of the cassettes pertain to antibiotic resistance. Resistance to third generation cephalosporins, multidrug resistance, and class 1 integrons were significantly more in E. hormaechei (clusters III, VI, VII, and VIII) than in the other species. The 30-day mortality rate and 100-day mortality did not differ significantly between patients with E. hormaechei and those with infections with the other species. In conclusion, the distribution of third generation cephalosporin resistance, multidrug resistance, and class 1 integrons were uneven among Enterobacter species. The resistance to third generation cephalosporins possessed significant impact on patient outcome.

[Analysis of etiological characteristics and establishment of prediction model of postoperative infections in patients undergoing oral squamous cell carcinoma surgery with free flap reconstruction]

OBJECTIVE

To investigate the characteristics of pathogen infection and to establish a prediction model of infections in oral squamous cell carcinoma patients undergoing surgery with free flap reconstruction.

METHODS

The retrospective cohort study consisted of 1 596 patients undergoing tumor resection and free flap reconstruction for oral squamous cell carcinoma from January 2018 to December 2020. According to the postoperative infection, the patients were divided into the infected group (n=154) and non-infected group (n=1 442). The characteristics of pathogens were analyzed in the infected patients. The primary outcome variable was postoperative infection, and Logistic regression was used to determine risk factors of the infection. The prediction model was established and the discriminatory accuracy of the model was evaluated using receiver operating characteristic (ROC) curve.

RESULTS

Totally 154 cases were infected in the 1 596 cases undergoing surgery with free flap reconstruction, and the infection rate was 9.65%. The most frequent sites of infection were the surgical wound and respiratory tract. A total of 268 pathogens were isolated and cultured, including 240 strains of Gram-negative bacteria, accounting for 89.55%, mainly Pseudomonas aeruginosa and Klebsiella pneumoniae; 23 strains of Gram-positive bacteria, accounting for 8.58%, mainly Enterococcus faecalis and Staphylococcus aureus; and 5 strains of fungi, accounting for 1.87%. The isolated Pseudomonas aeruginosa had high resistant rate to imipenem and meropenem, and was sensitive to antibiotics, such as ciprofloxacin. The isolated Staphylococcus aureus had high resistant rate to erythromycin and clindamycin, and was sensitive to vancomycin. According to the multivariate Logistic analysis, four independent variables were significantly associated with an increased risk of postoperative infection (P < 0.05): clinical N category≥1, the American Society of Anesthesiologists (ASA) grade ≥2, tracheotomy and length of hospital stay >13 d. The prediction model was established based on these factors and the expression of the risk prediction model was as follows: predicted probability value P=1/(1+e-a), a=-0.803+0.674×(clinical N category ≥1)+0.518×(the ASA grade ≥2)+0.918×(tracheotomy)+1.581×(length of hospital stay >13 d), Hosmer-Lemeshow χ2=10.647, P=0.223, the degree of fitting of the model was good. The area under the ROC curve was 0.818 and 95%CI of the model for predicting infection was 0.789-0.846.

CONCLUSION

Oral squamous cell carcinoma patients undergoing surgery with free flap reconstruction are prone to have a high incidence of postoperative infection and Gram-negative bacteria are the main pathogens causing an infection. The established prediction model is of good predictive effect. Rational antimicrobial use coupled with awareness of infection control measures is paramount to reduce the incidence of postoperative infection in the oral squamous cell carcinoma patients undergoing surgery with free flap reconstruction.

[Analysis of etiological characteristics and establishment of prediction model of postoperative infections in patients undergoing oral squamous cell carcinoma surgery with free flap reconstruction]

OBJECTIVE

To investigate the characteristics of pathogen infection and to establish a prediction model of infections in oral squamous cell carcinoma patients undergoing surgery with free flap reconstruction.

METHODS

The retrospective cohort study consisted of 1 596 patients undergoing tumor resection and free flap reconstruction for oral squamous cell carcinoma from January 2018 to December 2020. According to the postoperative infection, the patients were divided into the infected group (n=154) and non-infected group (n=1 442). The characteristics of pathogens were analyzed in the infected patients. The primary outcome variable was postoperative infection, and Logistic regression was used to determine risk factors of the infection. The prediction model was established and the discriminatory accuracy of the model was evaluated using receiver operating characteristic (ROC) curve.

RESULTS

Totally 154 cases were infected in the 1 596 cases undergoing surgery with free flap reconstruction, and the infection rate was 9.65%. The most frequent sites of infection were the surgical wound and respiratory tract. A total of 268 pathogens were isolated and cultured, including 240 strains of Gram-negative bacteria, accounting for 89.55%, mainly Pseudomonas aeruginosa and Klebsiella pneumoniae; 23 strains of Gram-positive bacteria, accounting for 8.58%, mainly Enterococcus faecalis and Staphylococcus aureus; and 5 strains of fungi, accounting for 1.87%. The isolated Pseudomonas aeruginosa had high resistant rate to imipenem and meropenem, and was sensitive to antibiotics, such as ciprofloxacin. The isolated Staphylococcus aureus had high resistant rate to erythromycin and clindamycin, and was sensitive to vancomycin. According to the multivariate Logistic analysis, four independent variables were significantly associated with an increased risk of postoperative infection (P < 0.05): clinical N category≥1, the American Society of Anesthesiologists (ASA) grade ≥2, tracheotomy and length of hospital stay >13 d. The prediction model was established based on these factors and the expression of the risk prediction model was as follows: predicted probability value P=1/(1+e^-a), a=-0.803+0.674×(clinical N category ≥1)+0.518×(the ASA grade ≥2)+0.918×(tracheotomy)+1.581×(length of hospital stay >13 d), Hosmer-Lemeshow χ²=10.647, P=0.223, the degree of fitting of the model was good. The area under the ROC curve was 0.818 and 95%CI of the model for predicting infection was 0.789-0.846.

CONCLUSION

Oral squamous cell carcinoma patients undergoing surgery with free flap reconstruction are prone to have a high incidence of postoperative infection and Gram-negative bacteria are the main pathogens causing an infection. The established prediction model is of good predictive effect. Rational antimicrobial use coupled with awareness of infection control measures is paramount to reduce the incidence of postoperative infection in the oral squamous cell carcinoma patients undergoing surgery with free flap reconstruction.

Mortality associated with third generation cephalosporin-resistance in Enterobacteriaceae infections: a multicenter cohort study in Southern China

Background: Emerging third-generation cephalosporin-resistant Enterobacteriaceae (3GCR-EB) pose global healthcare concern. This study assessed the in-hospital mortality attributed to 3GCR-EB.Methods: The study cohort comprised inpatients with community-onset or healthcare-associated infection caused by Enterobacteriaceae in three tertiary-care public hospitals in 2017. In-hospital mortality was compared between 3GCR-EB infected patients and third-generation cephalosporin-susceptible Enterobacteriaceae (3GCS-EB) infected patients using competing risk survival models.Results: Of 2,343 study patients (median age 60 years; 45.2% male), 1,481 (63.2%) had 3GCS-EB and 862 (36.8%) 3GCR-EB infection. 494 (57.0%) 3GCR-EB isolates were co-resistant to fluoroquinolones and 15 (1.7%) to carbapenems. In-hospital mortality was similar in 3GCS-EB and 3GCR-EB infections (2.4% vs. 2.8%; p = 0.601). No increase in the hazard of in-hospital mortality was detected for 3GCR-EB compared to 3GCS-EB infection (sub-distribution hazard ratio [HR] 0.80; 95%CI, 0.41-1.55) adjusting for patient age, sex, intensive care admission, origin of infection and site of infection. Analysis of cause-specific hazards showed that 3GCR-EB infections significantly decreased the daily rate of hospital discharge (cause-specific HR = 0.84; 95%CI, 0.76-0.92) leading to lengthier hospitalizations.Conclusion: 3GCR-EB infection per se was not associated with increased in-hospital mortality in this study, but placed significant healthcare burden by increasing the length of hospitalization.

Impact of Prior Antibiotic Use in Primary Care on Escherichia coli Resistance to Third Generation Cephalosporins: A Case-Control Study

Research is lacking on the reversibility of antimicrobial resistance (AMR). Thus, we aimed to determine the influence of previous antibiotic use on the development and decay over time of third generation cephalosporin (3GC)-resistance of E. coli. Using the database of hospital laboratories of the Autonomous Province of Bolzano/Bozen (Italy), anonymously linked to the database of outpatient pharmaceutical prescriptions and the hospital discharge record database, this matched case-control study was conducted including as cases all those who have had a positive culture from any site for 3GC resistant E. coli (3GCREC) during a 2016 hospital stay. Data were analyzed by conditional logistic regression. 244 cases were matched to 1553 controls by the date of the first isolate. Male sex (OR 1.49, 95% CI 1.10–2.01), older age (OR 1.11, 95% CI 1.02–1.21), the number of different antibiotics taken in the previous five years (OR 1.20, 95% CI 1.08–1.33), at least one antibiotic prescription in the previous year (OR 1.92, 95% CI 1.36–2.71), and the diagnosis of diabetes (OR 1.57, 95% CI 1.08–2.30) were independent risk factors for 3GCREC colonization/infection. Patients who last received an antibiotic prescription two years or three to five years before hospitalization showed non-significant differences with controls (OR 0.97, 95% CI 0.68–1.38 and OR 0.85, 95% CI 0.59–1.24), compared to an OR of 1.92 (95% CI 1.36–2.71) in those receiving antibiotics in the year preceding hospitalization. The effect of previous antibiotic use on 3GC-resistance of E. coli is highest after greater cumulative exposure to any antibiotic as well as to 3GCs and in the first 12 months after antibiotics are taken and then decreases progressively.

Clinical Impact and Risk Factors of Nonsusceptibility to Third-Generation Cephalosporins Among Hospitalized Adults with Monomicrobial Enterobacteriaceae Bacteremia in Southern Taiwan: A Multicenter Study

Background

Reducing the effectiveness of broad-spectrum cephalosporins against Enterobacteriaceae infections has been recognized. This study aimed to investigate risk factors and clinical significance of third-generation cephalosporin nonsusceptibility (3GC-NS) among the cases of monomicrobial Enterobacteriaceae bacteremia (mEB) at regional or district hospitals.

Methods

The study was conducted at three hospitals in southern Taiwan between Jan. 2017 and Oct. 2019. Only the first episode of mEB from each adult (aged ≥20 years) was included. The primary outcome was in-hospital crude mortality.

Results

Overall there were 499 episodes of adults with mEB included, and their mean age was 74.5 years. Female predominated, accounting for 53% of all patients. Escherichia coli (62%) and Klebsiella pneumoniae (21%) were two major causative species. The overall mortality rate was 15% (73/499), and patients infected by 3GC-NS isolates (34%, 172/499) had a higher mortality rate than those by 3GC-susceptible isolates (66%, 327/499) (21% vs 11%, P=0.005). By the multivariate analysis, 3GC-NS was the only independent prognostic determinant (adjusted odds ratio [AOR], 1.78; P=0.04). Of note, male (AOR 2.02, P=0.001), nosocomial-acquired bacteremia (AOR 2.77, P<0.001), and usage of nasogastric tube (AOR 2.01, P=0.002) were positively associated with 3GC-NS, but P. mirabilis bacteremia (AOR 0.28, P=0.01) and age (AOR 0.98, P=0.04) negatively with 3GC-NS.

Conclusion

For adults with Enterobacteriaceae bacteremia, 3GC-NS signifies a significant prognostic impact. Efforts to rapid identification of such antimicrobial resistance profiles should be incorporated into antimicrobial stewardship programs to achieve favorable outcomes.

Antimicrobial resistance profiles of microorganisms isolated from hospitalized patients in Dominican Republic

Objective.

To define the antimicrobial resistance profiles of the microorganisms most commonly isolated from hospitalized adult patients in Dominican Republic (DR).

Methods.

A retrospective, cross-sectional study of phenotypic antimicrobial susceptibility patterns was conducted using data from 3 802 clinical microbiology reports specifying positive bacterial cultures in samples collected from patients admitted to the clinical, surgery, and intensive care units (ICU) at three tertiary-level care hospitals in the city of Santiago de los Caballeros from 1 January 2016 – 31 December 2017. Descriptive statistics and chi-square test (P ≤ 0.05) were used to analyze the qualitative variables.

Results.

At the three hospitals, there were 932, 1 090, and 1 780 microbiology reports analyzed. Of the total, 1274 were from the ICU, 1 042 from the surgery unit, and 1 486 from the clinical unit. Methicillin resistance was found in 57.3% of the Staphylococcus aureus isolates and 75.3% of the coagulase-negative staphylococci. Third-generation cephalosporin resistance was detected in 54.4% of isolates identified as members of the Enterobacteriaceae family, 67.3% of the Acinetobacter spp., and 91.7% of the Pseudomonas, while carbapenem resistance was shown by 8.0%, 23.8%, and 51.0% of these, respectively. Most of the resistant Acinetobacter spp. isolates were found in just one hospital and the prevalence of Enterobacteriaceae resistant to carbapenems was highest in the ICU.

Conclusion.

Antimicrobial resistance levels are high among hospitalized patients in Dominican Republic and may cause enhanced risk factors that impact clinical outcomes. Urgent measures are needed to address antimicrobial resistance in DR.

An overview of cephalosporin antibiotics as emerging contaminants: a serious environmental concern

Antibiotics have been categorized as emerging pollutants due to their indiscriminate usage, continuous input and persistence in various environmental matrices even at lower concentrations. Cephalosporins are the broad-spectrum antibiotics of β-lactam family. Owing to its enormous production and consumption, it is reported as the second most prescribed antibiotic classes in Europe. The cephalosporin wastewater contains toxic organic compounds, inorganic salts, and active pharmaceutical ingredients (API) which pose a potential threat to the organisms in the environment. Therefore, removal of cephalosporin antibiotics from the environment has become mandatory as it contributes to increase in the level of chemical oxygen demand (COD), causing toxicity of the effluent and production of cephalosporin-resistant microbes. So far, several processes have been reported for degradation/removal of cephalosporins from the environment. A number of individual studies have been published within the last decade covering the various aspects of antibiotics. However, a detailed compilation on cephalosporin antibiotics as an emerging environmental contaminant is still lacking. Hence, the present review intends to highlight the current ecological scenario with respect to distribution, toxicity, degradation, various remediation technologies, and the regulatory aspects concerning cephalosporins. The latest successful technologies for cephalosporin degradation/removal discussed in this review will help researchers for a better understanding of the nature and persistence of cephalosporins in the environment along with the risks associated with their existence. The research thrust discussed in this review will also evoke new technologies to be attempted by the future researchers to develop sustainable options to remediate cephalosporin-contaminated environments.

An evaluation of multidrug-resistant (MDR) bacteria in patients with urinary stone disease: data from a high-volume stone management center

PURPOSE

To investigate the prevalence of MDR bacteria in patients with urinary stones and the risk factors for its formation.

METHODS

A retrospective study was performed among patients with urinary stones in Beijing Tsinghua Changgung Hospital from December 2014 to May 2018. Patients with positive urinary cultures and drug sensitivity results were included. MDR were defined as any bacteria that have resistance to at least one agent in at least three classes of antibiotics. Bacteria distribution and resistance patterns were calculated.

RESULTS

1655 patients with urinary stones were eligible for analysis, among which 367 patients had positive urinary culture, yielding 457 isolates of 45 species. Escherichia coli remained the most common organism with a prevalence of 29.3%, followed by Enterococcus faecalis (12.0%), Proteus mirabilis (10.5%), and Klebsiella pneumonia (6.8%). 44.4% isolates were identified as MDR. The three most common Gram-negative bacteria were Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae, with a MDR rate of 84.33%, 62.5%, and 48.39%, respectively. Drug-resistant rates were different between MDR and non-MDR in ampicillin, cefazolin, ceftriaxone, cefepime, gentamicin, amikacin, and levofloxacin (all with p value < 0.05). In multivariate analysis, indwelling catheters (OR 3.1, 95% CI 1.07-8.98) and antibiotics use in the last 3 months (OR 2.14, 95% CI 1.04-4.38) were significantly associated with MDR formation.

CONCLUSIONS

MDR bacteria were common among patients with urinary stones in our center and achieved high drug-resistant rates in ampicillin, first-generation and part of third-generation cephalosporins, and fluoroquinolones. Indwelling catheters and antibiotics used in the last 3 months were independent risk factors for MDR formation. Tailored antibacterial strategies still should be established according to the local bacterial spectrum and patient condition.

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy

The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439-5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238-3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002-2.090; P = 0.049).Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae.

Susceptibility of Austrian Clinical Klebsiella and Enterobacter Isolates Linked to Patient-Related Data

The aim of the study was to analyze the antimicrobial susceptibility of Austrian clinical Klebsiella sp. and Enterobacter sp. isolates linked to patient-related data over a time period from 1998 to 2014. The main findings of this study were (i) a marked difference of antibiotic susceptibility rates between different infection sites for both Klebsiella sp. and Enterobacter sp., (ii) significantly greater percentages of resistant isolates among both Klebsiella sp. and Enterobacter sp. in male patients compared to female patients and (iii) significantly greater percentages of resistant isolates among both Klebsiella sp. and Enterobacter sp. from hospital-derived samples compared to samples from the community. In conclusion, our statistical data analysis clearly indicated a strong association of patient-related data and Klebsiella sp. and Enterobacter sp. susceptibility profiles.