Carbapenem-Resistant Enterobacterales in Long-Term Care Facilities: A Global and Narrative Review

Ceftazidime/avibactam versus polymyxin B in carbapenem-resistant Klebsiella pneumoniae infections: a propensity score-matched multicenter real-world study

OBJECTIVES

In this retrospective observational multicenter study, we aimed to assess efficacy and mortality between ceftazidime/avibactam (CAZ/AVI) or polymyxin B (PMB)-based regimens for the treatment of Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections, as well as identify potential risk factors.

METHODS

A total of 276 CRKP-infected patients were enrolled in our study. Binary logistic and Cox regression analysis with a propensity score-matched (PSM) model were performed to identify risk factors for efficacy and mortality.

RESULTS

The patient cohort was divided into PMB-based regimen group (n = 98, 35.5%) and CAZ/AVI-based regimen group (n = 178, 64.5%). Compared to the PMB group, the CAZ/AVI group exhibited significantly higher rates of clinical efficacy (71.3% vs. 56.1%; p = 0.011), microbiological clearance (74.7% vs. 41.4%; p < 0.001), and a lower incidence of acute kidney injury (AKI) (13.5% vs. 33.7%; p < 0.001). Binary logistic regression revealed that the treatment duration independently influenced both clinical efficacy and microbiological clearance. Vasoactive drugs, sepsis/septic shock, APACHE II score, and treatment duration were identified as risk factors associated with 30-day all-cause mortality. The CAZ/AVI-based regimen was an independent factor for good clinical efficacy, microbiological clearance, and lower AKI incidence.

CONCLUSIONS

For patients with CRKP infection, the CAZ/AVI-based regimen was superior to the PMB-based regimen.

Carbapenemase-producing Enterobacterales isolated from hospital sinks: molecular relationships with isolates from patients and the change in contamination status after daily disinfection with sodium hypochlorite

Objective

This study aimed to investigate the contamination status of hospital sinks with carbapenemase-producing Enterobacterales (CPE), the efficacy of daily cleaning with sodium hypochlorite, and the relationships between CPEs isolated from contaminated sinks and patients.

Design

Pre/postintervention surveys of the CPE-contaminated sinks.

Setting

Hospital wards including pediatric intensive care unit in a children's hospital.

Participants

Consenting CPE-colonized patients admitted between November 2018 and June 2021 in our hospital.

Methods

Environmental culture of 180 sinks from nine wards in our hospital was performed three times with an interval of 2 years (2019, 2021, 2023). Molecular typing of the isolated strains from the sinks and patients was performed. After the first surveillance culture, we initiated daily disinfection of the sinks using sodium hypochlorite.

Results

Before the intervention, we detected 30 CPE-positive sinks in 2019. After the intervention with sodium hypochlorite, we observed a substantial decline in the number of sinks contaminated with CPE; 13 in 2021 and 6 in 2023. However, the intervention did not significantly reduce the number of CPE-contaminated sinks used for the disposal of nutrition-rich substances. The CPE isolates from the patients and those from the sinks of the wards or floors where they were admitted tended to have similar pulse-field gel electrophoresis patterns.

Conclusion

Contaminated sinks could be reservoirs of disseminating CPE to the patients. Daily disinfection of sinks with sodium hypochlorite may be effective in eliminating CPE, although the effect could be weaker in sinks with a greater risk of contact with nutrition-rich substances.

Implications of deduplication on the detection rates of multidrug-resistant organism (MDRO) in various specimens: insights from the hospital infection surveillance program

BACKGROUND

Currently, different guidelines recommend using different methods to determine whether deduplication is necessary when determining the detection rates of multidrug-resistant organisms (MDROs). However, few studies have investigated the effect of deduplication on MDRO monitoring data. In this study, we aimed to investigate the influence of deduplication on the detection rates of MDROs in different specimens to assess its impact on infection surveillance outcomes.

METHODS

Samples were collected from hospitalized patients admitted between January 2022 and December 2022; four types of specimens were collected from key monitored MDROs, including sputum samples, urine samples, blood samples, and bronchoalveolar lavage fluid (BALF) samples. In this study, we compared and analysed the detection rates of carbapenem-resistant Klebsiella pneumoniae (CRKP), carbapenem-resistant Escherichia coli (CRECO), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and methicillin-resistant Staphylococcus aureus (MRSA) under two conditions: with and without deduplication.

RESULTS

When all specimens were included, the detection rates of CRKP, CRAB, CRPA, and MRSA without deduplication (33.52%, 77.24%, 44.56%, and 56.58%, respectively) were significantly greater than those with deduplication (24.78%, 66.25%, 36.24%, and 50.83%, respectively) (all P < 0.05). The detection rates in sputum samples were significantly different between samples without duplication (28.39%, 76.19%, 46.95%, and 70.43%) and those with deduplication (19.99%, 63.00%, 38.05%, and 64.50%) (all P < 0.05). When deduplication was not performed, the rate of detection of CRKP in urine samples reached 30.05%, surpassing the rate observed with deduplication (21.56%) (P < 0.05). In BALF specimens, the detection rates of CRKP and CRPA without deduplication (39.78% and 53.23%, respectively) were greater than those with deduplication (31.62% and 42.20%, respectively) (P < 0.05). In blood samples, deduplication did not have a significant impact on the detection rates of MDROs.

CONCLUSION

Deduplication had a significant effect on the detection rates of MDROs in sputum, urine, and BALF samples. Based on these data, we call for the Infection Prevention and Control Organization to align its analysis rules with those of the Bacterial Resistance Surveillance Organization when monitoring MDRO detection rates.

Epidemiology of carbapenem-resistant organisms in Alameda County, California, 2019-2021

Objective

Carbapenem-resistant organisms (CROs) are an urgent health threat. Since 2017, Alameda County Health Public Health Department (ACPHD) mandates reporting of carbapenem-resistant Enterobacterales (CRE) and encourages voluntary reporting of non-CRE CROs including carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Surveillance data from ACPHD were analyzed to describe the epidemiology of CROs and target public health interventions.

Methods

Healthcare facilities in Alameda County reported CRO cases and submitted isolates to ACPHD to characterize carbapenemase genes; deaths were identified via the California Electronic Death Registration System. CRO cases with isolates resistant to one or more carbapenems were analyzed from surveillance data from July 2019 to June 2021.

Results

Four hundred and forty-two cases of CROs were reported to Alameda County from 408 patients. The county case rate for CROs was 29 cases per 100,000 population, and cases significantly increased over the 2-year period. CRPA was most commonly reported (157 cases, 36%), and cases of CRAB increased 1.83-fold. One-hundred eighty-six (42%) cases were identified among residents of long-term care facilities; 152 (37%) patients had died by January 2022. One hundred and seven (24%) cases produced carbapenemases.

Conclusions

The high burden of CROs in Alameda County highlights the need for continued partnership on reporting, testing, and infection prevention to limit the spread of resistant organisms. A large proportion of cases were identified in vulnerable long-term care residents, and CRAB was an emerging CRO among this population. Screening for CROs and surveillance at the local level are important to understand epidemiology and implement public health interventions.

Development of a risk prediction model for subsequent infection after colonization with carbapenem-resistant Enterobacterales: a retrospective cohort study

BACKGROUND

Colonization of carbapenem-resistant Enterobacterale (CRE) is considered as one of vital preconditions for infection, with corresponding high morbidity and mortality. It is important to construct a reliable prediction model for those CRE carriers with high risk of infection.

METHODS

A retrospective cohort study was conducted in two Chinese tertiary hospitals for patients with CRE colonization from 2011 to 2021. Univariable analysis and the Fine-Gray sub-distribution hazard model were utilized to identify potential predictors for CRE-colonized infection, while death was the competing event. A nomogram was established to predict 30-day and 60-day risk of CRE-colonized infection.

RESULTS

879 eligible patients were enrolled in our study and divided into training (n = 761) and validation (n = 118) group, respectively. There were 196 (25.8%) patients suffered from subsequent CRE infection. The median duration of subsequent infection after identification of CRE colonization was 20 (interquartile range [IQR], 14-32) days. Multisite colonization, polymicrobial colonization, catheterization and receiving albumin after colonization, concomitant respiratory diseases, receiving carbapenems and antimicrobial combination therapy before CRE colonization within 90 days were included in final model. Model discrimination and calibration were acceptable for predicting the probability of 60-day CRE-colonized infection in both training (area under the curve [AUC], 74.7) and validation dataset (AUC, 81.1). Decision-curve analysis revealed a significantly better net benefit in current model. Our prediction model is freely available online at https://ken-zheng.shinyapps.io/PredictingModelofCREcolonizedInfection/ .

CONCLUSIONS

Our nomogram has a good predictive performance and could contribute to early identification of CRE carriers with a high-risk of subsequent infection, although external validation would be required.

Antimicrobial Use and Carbapenem-Resistant Enterobacterales in Korea: A Nationwide Case-Control Study With Propensity Score Matching

BACKGROUND

Nationwide research on the association between carbapenem-resistant Enterobacterales (CREs) and antibiotic use is limited.

METHODS

This nested case-control study analyzed Korean National Health Insurance claims data from April 2017 to April 2019. Based on the occurrence of CRE, hospitalized patients aged ≥ 18 years were classified into CRE (cases) and control groups. Propensity scores based on age, sex, modified Charlson comorbidity score, insurance type, long-term care facility, intensive care unit stay, and acquisition of vancomycin-resistant Enterococci were used to match the case and control groups (1:3).

RESULTS

After matching, the study included 6,476 participants (1,619 cases and 4,857 controls). Multivariable logistic regression analysis revealed that the utilization of broad-spectrum antibiotics, such as piperacillin/tazobactam (adjusted odds ratio [aOR], 2.178; 95% confidence interval [CI], 1.829-2.594), third/fourth generation cephalosporins (aOR, 1.764; 95% CI, 1.514-2.056), and carbapenems (aOR, 1.775; 95% CI, 1.454-2.165), as well as the presence of comorbidities (diabetes [aOR, 1.237; 95% CI, 1.061-1.443], hemiplegia or paraplegia [aOR, 1.370; 95% CI, 1.119-1.679], kidney disease [aOR, 1.312; 95% CI, 1.105-1.559], and liver disease [aOR, 1.431; 95% CI, 1.073-1.908]), were significantly associated with the development of CRE. Additionally, the CRE group had higher mortality (8.33 vs. 3.32 incidence rate per 100 person-months, P < 0.001) and a total cost of healthcare utilization per person-month (15,325,491 ± 23,587,378 vs. 5,263,373 ± 14,070,118 KRW, P < 0.001) than the control group.

CONCLUSION

The utilization of broad-spectrum antibiotics and the presence of comorbidities are associated with increasing development of CRE. This study emphasizes the importance of antimicrobial stewardship in reducing broad-spectrum antibiotic use and CRE disease burden in Korea.

The Clinical Efficacy of Adding Ceftazidime/Avibactam to Standard Therapy in Treating Infections Caused by Carbapenem-Resistant Klebsiella pneumonia with blaOXA-48-like Genes

Ceftazidime/avibactam (CAZ-AVI) is FDA-approved for managing infections caused by resistant gram-negative bacilli, particularly infections via carbapenem-resistant Enterobacterales pathogens. The clinical data are still limited, particularly those in Saudi Arabia. The present study is a retrospective cohort study that was carried out at the Armed Forces Hospital in the southern region of Saudi Arabia to compare the clinical and microbiological outcomes for CAZ-AVI-treated patients as monotherapy and as an add-on to standard therapy for carbapenem-resistant Klebsiella pneumonia (CRKP) OXA-48 infections to those treated with standard drugs. The study included CRKP OXA-48-like infected patients who were administered antibiotics for more than seven days from 1 August 2018 to May 2023. Patients' baseline characteristics and demography were extracted from the clinical records, and their clinical/microbiology efficiencies were assessed as per the corresponding definitions. Univariate and multivariate logistic regressions were conducted to identify the potential independent variable for CAZ-AVI efficiency. A total of 114 patient files were included for the evaluation. Among these patients, 64 used CAZ-AVI combined with standard therapy and were included in the intervention group, and 50 of them used standard therapy and were included in the comparative group. Following analysis, CAZ-AVI's clinical success was 42.2% (p = 0.028), while the intervention versus comparative groups showed decreased 30-day all-cause mortality (50.0% versus 70.0%; p = 0.036) and infection recurrence (7.8% versus 24.0%; p = 0.019), as well as substantially increased rates of microbial eradication (68.8% versus 42.0%; p = 0.007). CAZ-AVI add-on therapy rather than monotherapy showed statistically significant favored clinical and microbial outcomes over the standard therapy. Furthermore, sex (female %), ICU admission, and fever were negatively associated with patients' 30-day all-cause mortality, serving as independent negative factors. Only fever, CRP bio levels, inotropes, and ICU admissions were significant predictors influencing the CAZ-AVI's clinical efficiency. The duration of CAZ-AVI therapy positively influenced CAZ-AVI's microbial eradication, while both WBC counts and fever experiences were negative predictors. This study shows the effective usage of CAZ-AVI against CRKP OXA-48-like infections. The influencing independent variables depicted here should recommend that clinicians individualize the CAZ-AVI dose based on co-existing risk factors to achieve optimal survival and efficacy. Prospective multicenter and randomized control studies are recommended, with individualized CAZ-AVI precision administration implemented based on patients' characteristics.

Genomic characterization of a WHO critical priority isolate Enterobacter kobei ST2070 harboring OXA-10, KPC-2, and CTX-M-12 recovered from a water irrigation channel in Ecuador

The discharge of untreated or partially treated wastewater can have detrimental impacts on the quality of water bodies, posing a significant threat to public health and the environment. In Ecuador, previous research indicates a high prevalence of antimicrobial resistant (AMR) bacteria in surface waters affected by human activities, including irrigation channels. In this study, we analyzed sediment samples collected from an irrigation channel utilized for agricultural purposes in northern Ecuador, using microbiological techniques and whole-genome sequencing (WGS). Our investigation revealed the first documented occurrence of E. kobei in Ecuador and the initial report of environmental E. kobei ST2070. Furthermore, we identified the coexistence of OXA-10-type class D β-lactamase and KPC-2-type class A β-lactamase in the E. kobei isolate (UTA41), representing the first report of such a phenomenon in this species. Additionally, we detected various antibiotic resistance genes in the E. kobei UTA41 isolate, including blaCTX-M-12, fosA, aac(6')-lb, sul2, msr(E), and mph(A), as well as virulence genes such as bacterial efflux pump and siderophore biosynthesis genes. We also identified two intact prophage regions (Entero_186 and Klebsi_phiKO2) in the isolate. Our study presents the first evidence of E. kobei isolate containing two carbapenemase-encoding genes in environmental samples from Latin America. This finding indicates the potential spread of critical-priority bacteria in water samples originating from anthropogenic sources, such as urban wastewater discharges and livestock facilities.

Simultaneous determination of five carbapenems, highly polar antibiotics, in milk by LC-MS/MS

The simultaneous determination of five carbapenems (biapenem, doripenem, ertapenem, imipenem, and meropenem) in raw and pasteurised bovine milk samples using LC-MS/MS was achieved and validated. Chromatographic separation was conducted on an InertSustain® AQ-C18 column using 0.1% formic acid in water and acetonitrile as the mobile phase. Target compounds were extracted using acetonitrile/water (20:80, v/v). After the removal of lipids with acetonitrile-saturated hexane, the dissolved protein was denatured with acetic acid. A portion of the supernatant was passed through an Oasis® PRiME HLB cartridge to remove the matrix. This novel method was validated in accordance with the Japanese validation guidelines and exhibited good trueness, ranging from 86.3% to 96.2%, using matrix-matched calibration curves. The relative standard deviation of repeatability ranged from 1.0% to 6.3%, and that of within-laboratory reproducibility ranged from 1.6% to 7.1%. The limit of quantification was 1.0 µg kg-1 for all analytes. None of the 60 milk samples commercially available in Tokyo contained any analytes. This novel method exhibited high-quality performance and can easily be implemented for the routine monitoring of carbapenems, which are highly polar antibiotics in milk.

Molecular characterization of carbapenem-resistance in Gram-negative isolates obtained from clinical samples at Jimma Medical Center, Ethiopia

Background

In resource-constrained settings, limited antibiotic options make treating carbapenem-resistant bacterial infections difficult for healthcare providers. This study aimed to assess carbapenemase expression in Gram-negative bacteria isolated from clinical samples in Jimma, Ethiopia.

Methods

A cross-sectional study was conducted to assess carbapenemase expression in Gram-negative bacteria isolated from patients attending Jimma Medical Center. Totally, 846 Gram-negative bacteria were isolated and identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Phenotypic antibiotic resistance patterns were determined using the Kirby-Bauer disk diffusion method and Etest strips. Extended-spectrum β-lactamase phenotype was determined using MAST disks, and carbapenemases were characterized using multiplex polymerase chain reactions (PCR).

Results

Among the isolates, 19% (157/846) showed phenotypic resistance to carbapenem antibiotics. PCR analysis revealed that at least one carbapenemase gene was detected in 69% (107/155) of these strains. The most frequently detected acquired genes were blaNDM in 35% (37/107), blaVIM in 24% (26/107), and blaKPC42 in 13% (14/107) of the isolates. Coexistence of two or more acquired genes was observed in 31% (33/107) of the isolates. The most common coexisting acquired genes were blaNDM + blaOXA-23, detected in 24% (8/33) of these isolates. No carbapenemase-encoding genes could be detected in 31% (48/155) of carbapenem-resistant isolates, with P. aeruginosa accounting for 85% (41/48) thereof.

Conclusion

This study revealed high and incremental rates of carbapenem-resistant bacteria in clinical samples with various carbapenemase-encoding genes. This imposes a severe challenge to effective patient care in the context of already limited treatment options against Gram-negative bacterial infections in resource-constrained settings.

Healthcare-Associated Infections and Prevention Programs in General Nursing versus Residential Homes-Results of the Point Prevalence Survey in Polish Long-Term Care Facilities

Background and Objectives: The number of residents of long-term care facilities (LTCFs) is expected to increase. Determining the epidemiological situation in the context of organizational conditions is therefore extremely important for planning the necessary future activities in the field of infection prevention. The aim of this study was to analyze the prevalence rates in Polish nursing vs. residential homes, in the context of the medical and functional burdens of residents and the organizational conditions of both types of units. Material and Methods: the data that were analyzed came from a point prevalence survey of infections and antibiotic consumption in LTCFs, conducted in accordance with the HALT-3 protocol in Poland in 2017, between April and June. Results: This study included a total of 2313 residents in 24 LTCFs. The most common risk factors for infections in the study population were urinary and fecal incontinence (77.0%), impaired mobility (the patient was in a wheelchair or lying down) (68.7%), and impaired spatial and temporal orientation (52.5%). The median prevalence in nursing homes (NHs) was 3.2% and that in residential homes (RHs) was 0.7%, but without statistical significance. The median for the entire group was 2.6%. A total of 93 healthcare-related infections were detected in 91 residents. The most frequently reported forms of infections were urinary tract infections, lower respiratory tract infections, and skin infections. A statistically significant positive correlation was found only between the percentage of residents with pressure ulcers and other wounds and the incidence of gastrointestinal infections (correlation coefficient = 0.413, p < 0.05). Infection prevention and control measures were implemented mainly in nursing homes, and in residential homes, only hand hygiene procedures were commonly available. Conclusions: For the two types of LTCFs, the epidemiological situation in terms of nosocomial infections is diverse. Consequently, both types of facilities require different approaches to infection control and prevention and outcomes analysis.

Carbapenem resistant Enterobacterales in the United Arab Emirates: a retrospective analysis from 2010 to 2021

Background

Carbapenem-resistant Enterobacterales (CRE) are spreading in the United Arab Emirates (UAE) where their dissemination is facilitated by international travel, trade, and tourism. The objective of this study is to describe the longitudinal changes of CRE as reported by the national AMR surveillance system of the UAE.

Methods

In this study, we retrospectively describe CRE isolated from 317 surveillance sites, including 87 hospitals and 230 centers/clinics from 2010 to 2021. The associated clinical, demographic, and microbiological characteristics are presented by relying on the UAE national AMR surveillance program. Data was analyzed using WHONET microbiology laboratory database software (http://www.whonet.org).

Results

A total of 14,593 carbapenem resistant Enterobacterales were analyzed, of which 48.1% were carbapenem resistant Klebsiella pneumoniae (CRKp), 25.1% carbapenem resistant Escherichia coli (CREc), and 26.8% represented 72 other carbapenem resistant species. Carbapenem resistant strains were mostly associated with adults and isolated from urine samples (36.9% of CRKp and 66.6% of CREc) followed by respiratory samples (26.95% for CRKp) and soft tissue samples (19.5% for CRKp). Over the studied period carbapenem resistance rates remained high, especially in K. pneumoniae, and in 2021 were equivalent to 67.6% for imipenem, 76.2% for meropenem, and 91.6% for ertapenem. Nevertheless, there was a statistically significant decreasing trend for imipenem and meropenem resistance in Klebsiella species (p < 0.01) while the decrease in ertapenem resistance was non-significant. Concerning E. coli, there was a statistically significant decreasing trend for meropenem and imipenem resistance over the 12 years, while ertapenem resistance increased significantly with 83.8% of E. coli exhibiting ertapenem resistance in 2021. Resistance rates to ceftazidime and cefotaxime remained higher than 90% (in 2021) for CRKp and cefotaxime rates increased to 90.5% in 2021 for CREc. Starting 2014, resistance to colistin and tigecycline was observed in carbapenem resistant Enterobacterales. CRE were associated with a higher mortality (RR: 6.3), admission to ICU (RR 3.9), and increased length of stay (LOS; 10 excess inpatient days per CRE case).

Conclusion

This study supports the need to monitor CRE in the UAE and draws attention to the significant increase of ertapenem resistance in E. coli. Future surveillance analysis should include a genetic description of carbapenem resistance to provide new strategies.

Asymptomatic gastrointestinal carriage of multidrug-resistant carbapenemase-producing Enterobacteriaceae among children under five years in a Kenyan hospital

Objectives

Asymptomatic gastrointestinal carriage of carbapenem-resistant Enterobacteriaceae (CRE) is a threat to global health in developing countries with inadequate safe drinking water, poor hygiene, and weak antimicrobial stewardship; however, epidemiological data to guide CRE infection prevention and control is limited in these settings. We assessed asymptomatic CRE and carbapenem-producing Enterobacteriaceae (CPE) fecal carriage rates and associated risk factors among hospitalized children aged under 5 years.

Methods

We adopted a cross-sectional study at Mama Lucy Kibaki Hospital in Nairobi-City County, Kenya, between June and September 2022. We collected demographic and clinical characteristics using a structured questionnaire and clinical reports and analyzed stool/rectal swab samples by standard and automated bacteriological methods.

Results

Asymptomatic CRE and CPE fecal carriage rate was 2.25% (6/267), with six isolates recovered, predominated by Escherichia coli (33.33%) and Enterobacter cloacae subsp dissolvens (33.33%). Third-generation cephalosporin and ciprofloxacin resistance were highest in Citrobacter farmer and E. cloacae subsp cloacae. All CRE and CPE were multidrug-resistant, and except E. cloacae subsp cloacae, were 100% colistin-resistant.

Conclusions

Asymptomatic gastrointestinal carriage of multidrug-resistant-CRE among hospitalized children under 5 years, presents a substantial public health threat. This calls for continuous surveillance including molecular characterization of isolates, to inform infection prevention and antimicrobial stewardship adherence in line with local and global plans on AMR.

New Delhi metallo-β-lactamase-1-producing Citrobacter portucalensis belonging to the novel ST264 causing fatal sepsis in a vulnerable migratory sea turtle

Olive ridley (Lepidochelys olivacea) turtles migrate across tropical regions of the Atlantic, Pacific, and Indian Oceans. Worryingly, olive ridley populations have been declining substantially and is now considered a threatened species. In this regard, habitat degradation, anthropogenic pollution, and infectious diseases have been the most notorious threats for this species. We isolated a metallo-β-lactamase (NDM-1)-producing Citrobacter portucalensis from the blood sample of an infected migratory olive ridley turtle found stranded sick in the coast of Brazil. Genomic analysis of C. portucalensis confirmed a novel sequence type (ST), named ST264, and a wide resistome to broad-spectrum antibiotics. The production of NDM-1 by the strain contributed to treatment failure and death of the animal. Phylogenomic relationship with environmental and human strains from African, European and Asian countries confirmed that critical priority clones of C. portucalensis are spreading beyond hospital settings, representing an emerging ecological threat to marine ecosystems.

Epidemiological Characteristics of Carbapenem-Resistant Enterobacterales in Japan: A Nationwide Analysis of Data from a Clinical Laboratory Center (2016-2022)

In Japan, nationwide epidemiological surveys on carbapenem-resistant Enterobacterales (CREs), including comprehensive information, are scarce, with most data available only through public reports. This study analyzed data on the Enterobacterales family collected from nationwide testing centers between January 2016 and December 2022, focusing on isolates that met the criteria for CRE in Japan based on drug susceptibility. We investigated 5,323,875 Enterobacterales isolates of 12 different species; among 4696 (0.09%) CRE strains, the proportion of major CRE isolates was as follows: Escherichia coli, 31.3%; Klebsiella pneumoniae, 28.0%; Enterobacter cloacae, 18.5%; and Klebsiella aerogenes, 6.7%. Moreover, over a 7-year period, Providencia rettgeri, E. cloacae, K. aerogenes, and K. pneumoniae demonstrated relatively high CRE percentages of 0.6% (156/26,185), 0.47% (869/184,221), 0.28% (313/110,371), and 0.17% (1314/780,958), respectively. The number of CRE strains isolated from different samples was as follows: urine, 2390; respiratory specimens, 1254; stool, 425; blood, 252; others, 375. In the broader context, including colonization, the predominant isolates of CREs collected at nationwide testing centers are E. coli and K. pneumoniae. Furthermore, recently, attention has been directed toward less common CRE species, such as Klebsiella oxytoca and Providencia rettgeri, and thus, it might be necessary to continue monitoring these less common species.

Carbapenem-Resistant Klebsiella pneumoniae in Large Public Acute-Care Healthcare System, New York, New York, USA, 2016-2022

Controlling the spread of carbapenem-resistant Enterobacterales is a global priority. Using National Healthcare Safety Network data, we characterized the changing epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) in a large public health system in New York, New York, USA. During 2016-2020, CRKP cases declined; however, during 2021-June 2022, a notable increase occurred. Of 509 cases, 262 (51%) were considered community-onset, including 149 in patients who were living at home. Of 182 isolates with proven or presumptive (ceftazidime/avibactam susceptible) enzymes, 143 were serine carbapenemases; most confirmed cases were K. pneumoniae carbapenemase. The remaining 39 cases were proven or presumptive metallo-β-lactamases; all confirmed cases were New Delhi metallo-β-lactamases. After 2020, a marked increase occurred in the percentage of isolates possessing metallo-β-lactamases. Most patients with metallo-β-lactamases originated from long-term care facilities. An aggressive and universal program involving surveillance and isolation will be needed to control the spread of CRKP in the city of New York.

Epidemiology of Carbapenem-Resistant Enterobacteriaceae Bacteremia in Gyeonggi Province, Republic of Korea, between 2018 and 2021

The incidence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing since 2008, with Gyeonggi Province in South Korea being particularly vulnerable due to its large number of healthcare facilities. This study examines the trends of CRE occurrence in Gyeonggi Province over the past four years and the epidemiological characteristics of the infected patients. Patients with positive CRE blood cultures admitted to healthcare facilities in Gyeonggi Province from January 2018 to December 2021 were evaluated in this study. Risk factors for CRE-related death were analyzed using data from patients who died within 30 days of the last blood sampling. Older adults aged 70 years and above constituted the majority of patients with CRE bacteremia. Antibiotic use did not significantly affect mortality risk. Non-survivors were more common in tertiary hospitals and intensive care units and included patients with hypertension, malignant tumors, and multiple underlying diseases. Klebsiella pneumoniae was the most common CRE strain, with Klebsiella pneumoniae carbapenemase being the predominant carbapenemase. Our study suggests the endemicity of CRE in Gyeonggi Province and highlights the increasing isolation of CRE strains in South Korean long-term care hospitals within the province. Further, infection control measures and government support specific to each healthcare facility type are crucial.

Risk factors for colonization with multidrug-resistant Gram-negative bacteria and Clostridioides difficile in Long Term Care Facilities (LTCFs) residents: the evidence from 27 facilities in a high endemic setting

Introduction

Residency in LTCFs increases the likelihood of colonization with multidrug resistant Gram-negative bacteria (MDR-GNB). We assessed the prevalence and risk factors for enteric colonization by III-generation cephalosporins-resistant and carbapenem-resistant (CR) GNB in a large group of LTCFs in a high endemic setting. We also assessed the prevalence and risk factors for C. difficile colonization.

Methods

A point prevalence survey with rectal screening (RS) was conducted in 27 LTCFs in north Italy. Epidemiological and clinical variables on the survey day, history of hospitalization and surgery within one year, and antibiotics within three months, were collected. The presence of III-generation cephalosporin resistant and CR GNB was assessed using a selective culture on chromogenic medium and PCR for carbapenemase detection. The presence of C. difficile was assessed using ELISA for GDH and RT-PCR to identify toxigenic strains. Multi-variable analyses were performed using two-level logistic regression models.

Results

In the study period 1947 RSs were performed. The prevalence of colonization by at least one GNB resistant to III-generation cephalosporin was 51% (E. coli 65%, K. pneumoniae 14% of isolates). The prevalence of colonization by CR GNB was 6%. 6% of all isolates (1150 strains) resulted in a carbapenem-resistant K. pneumoniae, and 3% in a carbapenem-resistant E. coli. KPC was the most frequent carbapenemase (73%) identified by PCR, followed by VIM (23%). The prevalence of colonization by C. difficile was 11.7%. The presence of a medical device (OR 2.67) and previous antibiotic use (OR 1.48) were significantly associated with III-generation cephalosporin resistant GNB colonization. The presence of a medical device (OR 2.67) and previous hospitalization (OR 1.80) were significantly associated with CR GNB. The presence of a medical device (OR 2.30) was significantly associated with C. difficile colonization. Main previously used antibiotic classes were fluoroquinolones (32% of previously treated subjects), III-generation cephalosporins (21%), and penicillins (19%).

Conclusion

Antimicrobial stewardship in LTCFs is a critical issue, being previous antibiotic treatment a risk factor for colonization by MDR-GNB. The prevalence of colonization by III-generation cephalosporin and CR GNB among LTCF residents also underlines the importance to adhere to hand hygiene indications, infection prevention and control measures, and environmental hygiene protocols, more achievable than rigorous contact precautions in this type of social setting.

Carbapenem Resistance in Gram-Negative Bacteria: A Hospital-Based Study in Egypt

Background and Objectives: The global spread of carbapenem resistance and the resulting increase in mortality forced the World Health Organization (WHO) to claim carbapenem-resistant enterobacteriaceae (CRE) as global priority pathogens. Our study aimed to determine the prevalence of carbapenemase-encoding genes and major plasmid incompatibility groups among Gram-negative hospital-based isolates in Egypt. Material and Methods: This cross-sectional study was carried out at Mansoura University Hospitals over 12 months, from January to December 2019. All the isolates were tested for carbapenem resistance. The selected isolates were screened by conventional polymerase chain reaction (PCR) for the presence of carbapenemase genes, namely bla_KPC, bla_IMP, bla_VIM, and bla_NDM-1. PCR-based plasmid replicon typing was performed using the commercial PBRT kit. Results: Out of 150 isolates, only 30 (20.0%) demonstrated carbapenem resistance. Klebsiella pneumoniae was the most resistant of all isolated bacteria, and bla_NDM was the predominant carbapenemases gene, while the most prevalent plasmid replicons were the F replicon combination (FIA, FIB, and FII) and A/C. Plasmids were detected only in Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, and Pseudomonas aeruginosa. Remarkably, we found a statistically significant association between carbapenemase genes and plasmid replicons, including bla_NDM, IncA/C, and IncX. Conclusions: Our study demonstrated an alarming rise of plasmid-mediated carbapenem-resistant bacteria in our locality. The coexistence of resistance genes and plasmids highlights the importance of a targeted antibiotic surveillance program and the development of alternative therapeutic options at the local and international levels. Based on our results, we suggest a large-scale study with more Enterobacteriaceae isolates, testing other carbapenemase-encoding genes, and comparing the replicon typing method with other plasmid detection methods. We also recommend a national action plan to control the irrational use of antibiotics in Egypt.

Risk factors and molecular epidemiology of fecal carriage of carbapenem resistant Enterobacteriaceae in patients with liver disease

BACKGROUND

Carbapenem resistant Enterobacteriaceae (CRE) colonization is a risk factor for CRE infection. CRE infection results in an increase in mortality in patients with cirrhosis. However, minimal data regarding the prevalence and the risk factors of CRE colonization in patients with liver disease yet without liver transplantation are available. The present study aimed to investigate the prevalence, risk factors and molecular epidemiology characteristics of CRE fecal carriage among patients with liver disease.

METHODS

Stool specimens from 574 adult inpatients with liver disease were collected from December 2020 to April 2021. CRE were screened using selective chromogenic agar medium and identified by the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Antimicrobial susceptibility was determined using the broth microdilution method. Carbapenemase genes were characterized by polymerase chain reaction (PCR) and DNA sequencing. Multilocus sequence typing (MLST) was performed for Carbapenem Resistant Klebsiella pneumoniae (CR-KPN) isolates and Carbapenem Resistant Escherichia Coli (CR-ECO) isolates.

RESULTS

The total number of stool specimens (732) were collected from 574 patients with liver disease. 43 non-duplicated CRE strains were isolated from 39 patients with a carriage rate of 6.79% (39/574). The carriage rate was 15.60% (17/109) in patients with acute-on-chronic liver failure (ACLF). Multivariate analysis indicated that ACLF (P = 0.018), the history of pulmonary infection within past 3 months (P = 0.001) and the use of third generation cephalosporin/β-lactamases inhibitor within past 3 months (P = 0.000) were independent risk factors of CRE colonization in patients with liver disease. Klebsiella Pnuemoniae (KPN) (51.28%) and Escherichia coli (ECO) (30.77%) were main strains in these patients. All CRE strains showed high resistance to most antimicrobials except for polymyxin B and tigecycline. Most (83.72%, 36/43) of the CRE carried carbapenemase genes. bla_KPC-2 was the major carbapenemase gene. The molecular epidemiology of KPN were dominated by ST11, while the STs of ECO were scattered.

CONCLUSIONS

The present study revealed that CRE fecal carriage rates were higher in patients with ACLF than in patients without liver failure. ACLF, the history of pulmonary infection within past 3 months and the use of third generation cephalosporin/β-lactamases inhibitor within past 3 months were independent risk factors of CRE colonization in patients with liver disease. Regular CRE screening for hospitalized patients with liver disease should be conducted to limit the spread of CRE strain.

Clinical Risk Factors and Microbiological and Intestinal Characteristics of Carbapenemase-Producing Enterobacteriaceae Colonization and Subsequent Infection

Gastrointestinal colonization with carbapenem-resistant Enterobacteriaceae (CRE) is always a prerequisite for the development of translocated infections. Here, we sought to screen for fecal carriage of CRE and identify the risk factors for CRE colonization as well as subsequent translocated pneumonia in critically ill patients admitted to the intensive care unit (ICU) of a university hospital in China. We further focused on the intestinal flora composition and fecal metabolic profiles in CRE rectal colonization and translocated infection patients. Animal models of gastrointestinal colonization with a carbapenemase-producing Klebsiella pneumoniae (carbapenem-resistant K. pneumoniae [CRKP]) clinical isolate expressing green fluorescent protein (GFP) were established, and systemic infection was subsequently traced using an in vivo imaging system (IVIS). The intestinal barrier, inflammatory factors, and infiltrating immune cells were further investigated. In this study, we screened 54 patients hospitalized in the ICU with CRE rectal colonization, and 50% of the colonized patients developed CRE-associated pneumonia, in line with the significantly high mortality rate. Upon multivariate analysis, risk factors associated with subsequent pneumonia caused by CRE in patients with fecal colonization included enteral feeding and carbapenem exposure. Furthermore, CRKP colonization and translocated infection influenced the diversity and community composition of the intestinal microbiome. Downregulated propionate and butyrate probably play important and multiangle roles in regulating immune cell infiltration, inflammatory factor expression, and mucus and intestinal epithelial barrier integrity. Although the risk factors and intestinal biomarkers for subsequent infections among CRE-colonized patients were explored, further work is needed to elucidate the complicated mechanisms. IMPORTANCE Carbapenem-resistant Enterobacteriaceae have emerged as a major threat to modern medicine, and the spread of carbapenem-resistant Enterobacteriaceae is a clinical and public health problem. Gastrointestinal colonization by potential pathogens is always a prerequisite for the development of translocated infections, and there is a growing need to assess clinical risk factors and microbiological and intestinal characteristics to prevent the development of clinical infection by carbapenem-resistant Enterobacteriaceae.

Risk factors for colonization by carbapenemase-producing bacteria in Spanish long-term care facilities: a multicentre point-prevalence study

BACKGROUND

The emergence of carbapenemase-producing bacteria (CPB) has become a major public health concern. Long-term care facilities (LTCF) are potential reservoirs for multidrug-resistant micro-organisms (MDRO). However, data on CPB is limited. The study aims to determine the prevalence of MDRO and risk factors for CPB colonization among residents of LTCFs.

METHODS

A point-prevalence study was conducted at 14 LTCFs in Tenerife (Spain) between October 2020 and May 2021. Nasal and rectal swabs were cultured for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenemase-producing Enterobacterales, MDR Acinetobacter baumannii (MDR-Ab) and MDR Pseudomonas aeruginosa. Antimicrobial susceptibility testing and molecular detection of resistance genes were performed. Risk factors for colonization by carbapenemase-producing bacteria (CPB) were determined by univariate and multivariate analysis.

RESULTS

A total of 760 LTCF residents were recruited. The prevalence of colonization by CPB was 9.3% (n = 71) with the following distribution: 35 (49.3%) K. pneumoniae, 26 (36.6%) MDR-Ab, 17 (23.9%) E. coli, and 1 (1.4%) C. koseri. In addition, the prevalence of colonization by MRSA was 28.1% (n = 215) and only one case of VRE was isolated. Multivariate analysis identified male sex (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.86-3.11; P = 0.01), having a high health requirement (OR, 6.32; 95% CI, 1.91-20.92; P = 0.003) and previous hospitalization (OR, 3.60; 95% CI, 1.59-8.15 P = 0.002) as independent risk factors for CPB rectal carriage.

CONCLUSIONS

LTCFs are an important reservoir for MDRO, including CPB. We have identified some predictors of colonization by CPB, which enable a more targeted management of high-risk residents. Antimicrobial stewardship programmes and infection control preventive measures are needed to stop acquisition and transmission of MDRO.

Study on the Detection and Infection Distribution of Multidrug-Resistant Organisms in Different Specimens

Objective

To analyze the infection and distribution of multidrug-resistant organisms (MDRO) in different clinical specimens, thereby providing a reference for clinical diagnosis and treatment and prevention and control.

Patient and Methods

2314 strains of MDRO isolated from clinical specimens in the First Affiliated Hospital of Nanjing Medical University from January to December 2020. MDRO were collected by Information System. The detection rate of MDRO, infection rate, the proportion of infection, and detection rate of MDRO infection in different specimens were analyzed.

Results

The top three specimens in the detection rate of MDRO were BALF (60.71%), sputum (33.68%), and blood (28.79%). The top three specimens in the proportion of MDRO infection were blood (97.74), other sterile body fluids (90.35%), and BALF (90.20%). The top three specimens in the MDRO infection rate were BALF (9.75%), sputum (3.07%), and secretions (2.90%). The top three specimens in the detection rate of MDRO infection were sputum (0.63‰), other sterile body fluids (0.13‰), and secretions (0.11‰).

Conclusion

The detection and infection distribution of MDRO vary greatly in different specimens. The submission of sterile body fluids for examination should be strengthened and the standard of sample collection should be highlighted.

Therapeutic Drug Monitoring of Ceftazidime-Avibactam Concentrations in Carbapenem-Resistant K. pneumoniae-Infected Patients With Different Kidney Statuses

Aims: Carbapenem-resistant K. pneumoniae (CRKP) is the most common carbapenem-resistant Enterobacteriaceae with high mortality. Ceftazidime-avibactam (CAZ-AVI) has exhibited excellent in vitro activity in vivo against CRKP. However, the efficacy of CAZ-AVI in KPC-producing CRKP-infected patients with different kidney statuses varies, such as renal insufficiency, normal renal function, and augmented renal clearance (ARC). We explored the use of therapeutic drug monitoring (TDM) to evaluate the concentration and efficacy of CAZ-AVI in CRKP-infected patients with different kidney statuses.

Methods: Serum concentrations for CAZ and AVI were determined by the high-performance liquid chromatography method. Bacterial identification, routine susceptibility testing, renal function index, and others were performed in standard protocols in the hospital’s clinical laboratories.

Results: In the two patients with ARC, in case 1, CAZ-AVI 2.5g q6h was used with good efficacy, and the concentrations were up to the pharmacokinetics/pharmacodynamics targets. In Case 2, 2.5 g q8h was used with invalid effectiveness, and AVI C_min was only 0.797 mg/l, which is lower than the PK/PD target. Case 3 was renal insufficiency using CAZ-AVI 1.25 q8h, and case 4 was normal renal function using 2.5 g q8h. Their concentrations were both up to the PK/PD targets.

Conclusion: TDM results demonstrated that CAZ-AVI steady-state plasma concentration varies among patients with different kidney statuses, providing evidence for the utility of TDM of CAZ-AVI in individualized drug dose adjustment. ARC patients may need more CAZ-AVI daily doses than the standard dose.

Trends in DTR, CR, ECR, and FQR in Four Common Gram-Negative Bacteria: A Retrospective Study from 2013 to 2021

Purpose

The purpose of this study was to examine the prevalence of four important drug-resistance phenotypes: difficult-to-treat resistance (DTR), fluoroquinolone resistance (FQR), carbapenem resistance (CR), and extended-spectrum cephalosporin resistance (ECR).

Methods

DTR was defined as insensitivity to all the β-lactams and fluoroquinolones tested. We retrospectively analyzed the distribution characteristics of specific drug-resistant phenotypes of the main Gram-negative bacteria causing bloodstream infections (BSIs) in Tongji Hospital (Wuhan, China) between 2013 and 2021: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii.

Results

FQR was the main antimicrobial resistance phenotype of E. coli, accounting for 59.45% (1117/1879, 95% confidence interval, 57.21%-61.65%); the detection rates for CR and DTR were low, accounting for 1.86% (35/1879, 1.34%-2.58%), and 1.81% (34/1879, 1.30%-2.52%), respectively. However, the detection rates for CR and DTR in K. pneumoniae were 38.83% (497/1280, 36.20%-41.53%) and 35.94% (460/1280, 33.35%-38.60%), respectively. In P. aeruginosa, the detection rates of the four drug-resistant phenotypes (DTR, CR, FQR, and ECR) were all < 30%, but conversely, for A. baumannii, the detection rates were all > 80%. The changes in the data from 2013 to 2021 showed upward trends (z > 0) for CR-E. coli, DTR-E. coli, FQR-E. coli, CR-K. pneumoniae, DTR-K. pneumoniae, FQR-K. pneumoniae, and ECR-K. pneumoniae, but downward trends (z < 0) for ECR-E. coli, CR-A. baumannii, DTR-A. baumannii, FQR-A. baumannii, ECR-A. baumannii, CR-P. aeruginosa, DTR-P. aeruginosa, FQR-P. aeruginosa, and ECR-P. aeruginosa.

Conclusion

DTR warrants further attention, especially in in BSI-associated K. pneumoniae and A. baumannii, in which the detection rates were very high. Between 2013 and 2021 in this region, DTR-E. coli and CR-E. coli showed obvious upward trends, whereas DTR-P. aeruginosa and ECR-P. aeruginosa showed obvious downward trends.

Global Threat of Carbapenem-Resistant Gram-Negative Bacteria

Infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria (GNB), including carbapenem-resistant (CR) Enterobacterales (CRE; harboring mainly bla_KPC, bla_NDM, and bla_OXA-48-like genes), CR- or MDR/XDR-Pseudomonas aeruginosa (production of VIM, IMP, or NDM carbapenemases combined with porin alteration), and Acinetobacter baumannii complex (producing mainly OXA-23, OXA-58-like carbapenemases), have gradually worsened and become a major challenge to public health because of limited antibiotic choice and high case-fatality rates. Diverse MDR/XDR-GNB isolates have been predominantly cultured from inpatients and hospital equipment/settings, but CRE has also been identified in community settings and long-term care facilities. Several CRE outbreaks cost hospitals and healthcare institutions huge economic burdens for disinfection and containment of their disseminations. Parenteral polymyxin B/E has been observed to have a poor pharmacokinetic profile for the treatment of CR- and XDR-GNB. It has been determined that tigecycline is suitable for the treatment of bloodstream infections owing to GNB, with a minimum inhibitory concentration of ≤ 0.5 mg/L. Ceftazidime-avibactam is a last-resort antibiotic against GNB of Ambler class A/C/D enzyme-producers and a majority of CR-P. aeruginosa isolates. Furthermore, ceftolozane-tazobactam is shown to exhibit excellent in vitro activity against CR- and XDR-P. aeruginosa isolates. Several pharmaceuticals have devoted to exploring novel antibiotics to combat these troublesome XDR-GNBs. Nevertheless, only few antibiotics are shown to be effective in vitro against CR/XDR-A. baumannii complex isolates. In this era of antibiotic pipelines, strict implementation of antibiotic stewardship is as important as in-time isolation cohorts in limiting the spread of CR/XDR-GNB and alleviating the worsening trends of resistance.

The Distribution of K. pneumoniae in Different Specimen Sources and Its Antibiotic Resistance Trends in Sichuan, China From 2017 to 2020

Objective

We aim to analyze the distribution of Klebsiella pneumoniae in different specimen sources and its antibiotic resistance trends from the Antimicrobial Resistant Investigation Network of Sichuan Province (ARINSP) between 2017 and 2020.

Methods

According to the monitoring scheme, each participating hospital identified the bacteria and performed antimicrobial susceptibility tests using approved procedures. The data of non-repetitive isolates collected from outpatients and inpatients were submitted to ARINSP. The WHONET 5.6 software was used to analyze the results according to the Clinical and Laboratory Standards Institute (CLSI).

Results

Between 2017 and 2020, 833,408 non-repetitive clinical isolates of bacteria were isolated in total. The bacterial strains isolated from sputum and broncho-alveolar lavage accounted for 48.7, 56.4, 49.2, and 43.7% from 2017 to 2020 respectively, among all sources. The number of Klebsiella pneumoniae isolates from sputum and broncho-alveolar lavage increased from 18,809 in 2018, 19,742 in 2019, to 19,376 in 2020, playing a predominant role among all specimens. Meropenem-resistant K. pneumoniae occurrences (5.7% in 2017, 7.3% in 2018, 8.0% in 2019, and 7.5% in 2020) remained highest among carbapenems, and increased slightly over time. The resistance rate to tigecycline remained lowest, and declined from 2.4% in 2017, to 0.4% in 2018, and from 0.7% in 2019, to 0.6% in 2020.

Conclusion

The overall resistance rates of Klebsiella pneumoniae to carbapenems increased in Sichuan Province, giving a significant challenge to control K. pneumoniae related infections. Tigecycline has retained activity to against K. pneumoniae. Ongoing surveillance is essential. It can help for implementing intervention programs to reduce the occurrence of antimicrobial resistance and to provide with a rational use of antimicrobials.

Intra- and Extra-Hospital Dissemination of IMP-22-Producing Klebsiella pneumoniae in Northern Portugal: The Breach of the Hospital Frontier Toward the Community

The emergence of infections (and colonization) with Enterobacteriaceae-producing carbapenemases is a threatening public health problem. In the last decades, we watched an isolated case becoming a brutal outbreak, a sporadic description becoming an endemic problem. The present study aims to highlight the dissemination of IMP-22-producing Klebsiella pneumoniae in the North of Portugal, through the phenotypic and genotypic characterization of isolates collected from hospitalized patients (n=5) and out-patients of the emergency ward of the same acute care hospital (n=2), and isolates responsible for the intestinal colonization of residents in a Long-Term Care Facility (n=4). Pulsed-field gel electrophoresis (PFGE) results, associated with conjugation experiments pointed to a pattern of both vertical and horizontal dissemination. Overall, and complementing other studies that give relevance to IMP-22-producing K. pneumoniae in the clinical settings, here we show for the first time the public health threatening breach of the hospital frontier of this resistance threat, toward the community.

The Monte Carlo Simulation of Three Antimicrobials for Empiric Treatment of Adult Bloodstream Infections With Carbapenem-Resistant Enterobacterales in China

Introduction: The aim of this study was to predict and evaluate three antimicrobials for treatment of adult bloodstream infections (BSI) with carbapenem-resistant Enterobacterales (CRE) in China, so as to optimize the clinical dosing regimen further.

Methods: Antimicrobial susceptibility data of blood isolates were obtained from the Blood Bacterial Resistance Investigation Collaborative Systems in China. Monte Carlo simulation was conducted to estimate the probability target attainment (PTA) and cumulative fraction of response (CFR) of tigecycline, polymyxin B, and ceftazidime/avibactam against CRE.

Results: For the results of PTAs, tigecycline following administration of 50 mg every 12 h, 75 mg every 12 h, and 100 mg every 12 h achieved > 90% PTAs when minimum inhibitory concentration (MIC) was 0.25, 0.5, and 0.5 μg/mL, respectively; polymyxin B following administration of all tested regimens achieved > 90% PTAs when MIC was 1 μg/mL with CRE; ceftazidime/avibactam following administration of 1.25 g every 8 h, 2.5 g every 8 h achieved > 90% PTAs when MIC was 4 μg/mL, 8 μg/mL with CRE, respectively. As for CFR values of three antimicrobials, ceftazidime/avibactam achieved the lowest CFR values. The highest CFR value of ceftazidime/avibactam was 77.42%. For tigecycline and ceftazidime/avibactam, with simulated regimens daily dosing increase, the CFR values were both increased; the highest CFR of tigecycline values was 91.88%. For polymyxin B, the most aggressive dosage of 1.5 mg/kg every 12 h could provide the highest CFR values (82.69%) against CRE.

Conclusion: This study suggested that measurement of MICs and individualized therapy should be considered together to achieve the optimal drug exposure. In particular, pharmacokinetic and pharmacodynamic modeling based on local antimicrobial resistance data can provide valuable guidance for clinicians for the administration of empirical antibiotic treatments for BSIs.

Whole-Genome Sequencing (WGS) of Carbapenem-Resistant K. pneumoniae Isolated in Long-Term Care Facilities in the Northern Italian Region

K. pneumoniae (KPN) is one of the widest spread bacteria in which combined resistance to several antimicrobial groups is frequent. The most common β-lactamases found in K. pneumoniae are class A carbapenemases, both chromosomal-encoded (i.e., NMCA, IMI-1) and plasmid-encoded (i.e., GES-enzymes, IMI-2), VIM, IMP, NDM, OXA-48, and extended-spectrum β-lactamases (ESBLs) such as CTX-M enzymes. In the present study, a total of 68 carbapenem-resistant KPN were collected from twelve long-term care facilities (LTCFs) in the Northern Italian region. The whole-genome sequencing (WGS) of each KPN strain was determined using a MiSeq Illumina sequencing platform and analysed by a bacterial analysis pipeline (BAP) tool. The WGS analysis showed the prevalence of ST307, ST512, and ST37 as major lineages diffused among the twelve LTCFs. The other lineages found were: ST11, ST16, ST35, ST253, ST273, ST321, ST416, ST1519, ST2623, and ST3227. The bla_KPC-2, bla_KPC-3, bla_KPC-9, bla_SHV-11, bla_SHV-28, bla_CTX-M-15, bla_OXA-1, bla_OXA-9, bla_OXA-23, qnrS1, qnrB19, qnrB66, aac(6′)-Ib-cr, and fosA were the resistance genes widespread in most LTCFs. In this study, we demonstrated the spreading of thirteen KPN lineages among the LTCFs. Additionally, KPC carbapenemases are the most widespread β-lactamase.