Extended-spectrum Beta-lactamase-producing Klebsiella Pneumoniae Research Articles

Gut colonization and subsequent infection of neonates caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae.

The gut microbiota harbors diverse bacteria considered reservoirs for antimicrobial resistance genes. The global emergence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-PE) significantly contributes to healthcare-associated infections (HAIs). We investigated the presence of ESBL-producing Escherichia coli (ESBL-PEco) and ESBL-producing Klebsiella pneumoniae (ESBL-PKpn) in neonatal patients' guts. Furthermore, we identified the factors contributing to the transition towards ESBL-PEco and ESBL-PKpn-associated healthcare-associated infections (HAIs). The study was conducted from August 2019 to February 2020, in a Neonatal Intensive Care Unit of the Hospital Infantil de México Federico Gómez. Rectal samples were obtained upon admission, on a weekly basis for a month, and then biweekly until discharge from the neonatology ward. Clinical data, culture results, and infection information were gathered. We conducted antimicrobial tests, multiplex PCR assay, and pulsed-field gel electrophoresis (PFGE) to determine the antimicrobial resistance profile and genetic relationships. A comparison between the group's controls and cases was performed using the Wilcoxon and Student t-tests. Of the 61 patients enrolled, 47 were included, and 203 rectal samples were collected, identifying 242 isolates. In 41/47 (87%) patients, colonization was due to ESBL-PEco or ESBL-PKpn. And nine of them developed HAIs (22%, 9/41). ESBL-PEco resistance to cephalosporins ranged from 25.4% to 100%, while ESBL-PKpn resistance varied from 3% to 99%, and both bacteria were susceptible to carbapenems, tigecillin, and colistin. The prevalent bla CTX-M-group-1 gene accounted for 77.2% in ESBL-PEco and 82.2% in ESBL-PKpn, followed by bla TEM 50% and bla OXA-1 43.8% in ESBL-PEco and bla TEM 80.2% and bla SHV 76.2% in ESBL-PKpn. Analysis of clonality revealed identical colonizing and infection isolates in only seven patients. Significant risk factors included hospital stay duration, duration of antibiotic treatment, and invasive device usage. Our findings suggest high ESBL-PEco and ESBL-PKpn rates of colonization often lead to infection in neonates. Attention should be paid to patients with ESBL-PE.

Gut acquisition of Extended-spectrum β-lactamases-producing Klebsiella pneumoniae in preterm neonates: Critical role of enteral feeding, and endotracheal tubes in the neonatal intensive care unit (NICU).

Klebsiella spp. can colonize the intestine of preterm neonates, and over-growth has been associated with necrotizing enterocolitis, hospital-acquired infections, and late-onset sepsis. This could lead us to suggest that the clinical pertinence of intestinal colonization with ESBL in preterm neonates appears to be important. We conducted this study to characterize the genetic proprieties of ESBL-producing Klebsiella pneumoniae (ESBL-KP) under clinical isolates and to describe the risk factors for the intestinal tract acquisition event during hospitalization. One hundred and thirteen premature infants were recruited from the neonatal intensive care unit (NICU). All newborns are issued from the birth suites of the pregnancy department. Two rectal swabs were planned to define K. Pneumoniae intestinal carriage status. ESBL-KP was confirmed by Brilliance ESBL selective chromogenic Agar. Antimicrobial susceptibility testing including phenotypic testing and genotypic detection of the most commonly described ESBL genes was done. Logistic regression models were performed to find the variables associated with the acquisition event of ESBL-KP. A total of 62 (54.86%) premature neonates were colonized with ESBL-KP. The rate of blaSHV, blaTEM, blaCTX-M1, blaCTX-M2, blaCTX-M9, and blaOXA-48 genes among the isolates was 82, 48, 93.5, 4.8, 11.2 and 3.22%, respectively. We found that ESBLs K. Pneumoniae isolates were 100% resistant to amoxicillin, clavulanic acid-amoxicillin, cefotaxime, ceftazidime, and gentamicin. The regression model is for a given significant association between the tract intestinal of ESBL-KP acquisition events and the use of enteral tube feeding (OR = 38.46, 95% CI: 7.86-188.20, p-Value: 0.001), and endotracheal tubes (OR = 4.86, 95% CI: 1.37-17.19, p-Value 0.014). Our finding supposes that the enteral feeding tube and endotracheal tube might have a critical role in colonizing the intestinal tract of preterm infants. This highlights the current status of both practices that will require updated procedures in the NICU.

Gut microbiome dynamics in index patients colonized with extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales after hospital discharge and their household contacts.

This study investigated the gut microbiome dynamics of index patients colonized with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) (n = 5) or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) (n = 3) and their household contacts (n = 9) up to 4 months after hospital discharge of the index patient using 16S rRNA amplicon gene sequencing. Samples were collected at the day of hospital discharge of the index patient, 1 week and 2 and 4 months after discharge. Compared to household contacts, we observed a significant lower alpha diversity (P < 0.001) among index patients and significant (P < 0.05) separation between the two groups for beta diversity. Principal component analysis of the samples from each household (i.e., index patient and respective household contact) showed a clear shift in microbiome composition, in 4/8 index patients, from dissimilar to more similar to the household contact group. This suggests recovery of the microbiome to a healthier status, which was also reflected by de novo colonization of (health-associated) taxa. In contrast, the four time-point samples of the household contacts clustered together indicating a stable microbiome composition over time irrespective of low-level ESBL-Ec (n = 3) or ESBL-Kp (n = 2) colonization. In conclusion, here we show that, at the day of hospital discharge, the microbiome composition of index patients is dissimilar from that of household contacts. Over time, signals of microbiome recovery were observed in half of the index patients. The stable microbiome composition in household contacts irrespective of low-level ESBL-Ec or ESBL-Kp colonization suggests that the gut microbiome in these healthy people provided colonization resistance against ESBL-PE outgrowth. IMPORTANCE Colonization with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) often precedes infections and is therefore considered as a great threat for public health. Here, we studied the gut microbiome dynamics in eight index patients colonized with ESBL-PE after hospital discharge and the impact of exposure to this index patient on the gut microbiome dynamics of their household contacts. We showed that the microbiome composition from index patients is different from their household contacts upon hospital discharge and that, in some of the index patients, their microbiome composition over time shifted toward the composition of their household contacts. In contrast, household contacts showed a stable microbiome composition over time irrespective of low-level extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) gut colonization, suggesting that, in healthy microbiomes, colonization resistance is able to prevent ESBL-PE expansion.

Carriage of ESBL-producing Klebsiella pneumoniae and Escherichia coli among children in rural Ghana: a cross-sectional study

BackgroundExtended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae (ESBL-KP) and Escherichia coli (ESBL-EC) present a high burden in both communities and healthcare sectors, leading to difficult-to-treat infections. Data on intestinal carriage of ESBL-KP and ESBL-EC in children is scarce, especially in sub-Saharan African countries. We provide data on faecal carriage, phenotypic resistance patterns, and gene variation of ESBL-EC and ESBL-KP among children in the Agogo region of Ghana.MethodsFrom July to December 2019, fresh stool samples were collected within 24 h from children < 5 years with and without diarrhoea attending the study hospital. The samples were screened for ESBL-EC and ESBL-KP on ESBL agar and confirmed using double-disk synergy testing. Bacterial identification and an antibiotic susceptibility profile were performed using the Vitek 2 compact system (bioMérieux, Inc.). ESBL genes, blaSHV, blaCTX-M, and blaTEM were identified by PCR and further sequencing.ResultsOf the 435 children recruited, stool carriage of ESBL-EC and ESBL-KP was 40.9% (n/N = 178/435) with no significant difference in prevalence between children with diarrhoea and non-diarrhoea. No association between ESBL carriage and the age of the children was found. All isolates were resistant to ampicillin and susceptible to meropenem and imipenem. Both ESBL-EC and ESBL-KP isolates showed over 70% resistance to tetracycline and sulfamethoxazole-trimethoprim. Multidrug resistance was observed in over 70% in both ESBL-EC and ESBL-KP isolates. The blaCTX-M-15 was the most prevalent ESBL gene detected. blaCTX-M-27, blaCTX-M-14, and blaCTX-M-14b were found in non-diarrhoea stools of children, whereas blaCTX-M-28 was found in both the diarrhoea and non-diarrhoea patient groups.ConclusionsThe carriage of ESBL-EC and ESBL-KP among children with and without diarrhoea in the Agogo community with a high prevalence of blaCTX-M-15 is noteworthy, highlighting the importance of both the population as a possible reservoir. This study reports for the first time the ESBL gene blaCTX-M-28 among the studied populations in Ghana.

Critical priority Multidrug-Resistant Organisms (MDROs) secondary infection among COVID-19 patients: hidden threat during a pandemic? A retrospective study

Background: The global Coronavirus Disease 2019 (COVID-19) pandemic is superimposed on the ongoing Multidrug-Resistant Organisms (MDROs) pandemic. Bacterial co-infection, particularly those caused by MDROs, is one of the risk factors linked to higher morbidity and mortality rates in COVID-19 patients. This study aims to compare critical priority MDROs profile causing bacteremia in COVID-19 and non-COVID-19 patients during a pandemic. Methods: A hospital-based retrospective cross-sectional study was conducted at Dr. Soetomo General Academic Hospital from April 2020 to December 2021. This study used a consecutive sampling technique, which included and analyzed all identified microorganism isolates from blood specimens that met the inclusion criteria. The Mann-Whitney test was used to compare MDRO profiles between COVID-19 and non-COVID-19 patients, which is significant if p &lt; 0.05. Results: The total proportion of critical priority MDRO isolates in COVID-19 patients was 90/390 (23.08%), while in non-COVID-19 patients were 377/1446 (26.07%) isolates (p=0.228). Carbapenem-resistant Acinetobacter baumannii (CRAB) had a higher proportion of events in COVID-19 patients (12.05% vs. 7.05%, p &lt; 0.001). In contrast, extended-spectrum β-lactamases (ESBL)-producing Klebsiella pneumoniae (ESBL-KP) had a higher proportion of events in non-COVID patients (7.54% vs. 2.82%, p &lt; 0.001). Acinetobacter baumannii exhibited a high level of resistance, with 149/223 (66.82%) of the isolates being CRAB, with the COVID-19 group accounting for 47/59 (79.66%) and the non-COVID-19 group accounting for 102/164 (62.19%; z = 2.438; p = 0.015). Conclusion: The high proportion and resistance rate of critical priority MDROs, CRAB particularly, among COVID-19 patients, highlights the importance of effective AMR control practices and prevention strategies during the pandemic.

Successful Control of an Outbreak by Phenotypically Identified Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae in a Neonatal Intensive Care Unit.

Premature newborns represent a vulnerable population, at high risk of acquiring nosocomial infections during neonatal intensive care unit (NICU) admission. Multidrug-resistant organisms represent the greatest concern due to their intrinsic virulence and the limited therapeutic options. Resistant Enterobacterales are a growing threat for critically ill neonates, with increasing numbers of NICU outbreaks caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales being described. This study reports the early detection and successful control of an outbreak caused by ESBL-producing Klebsiella pneumoniae (ESBL-KP) in an Italian NICU in February 2021. A total of 13 newborns tested positive for ESBL-KP between 2-9 February 2021, of whom four (31%) had a bloodstream infection. Two were critically ill, extremely premature newborns who died because of multiple comorbidities, and two were cured after treatment with meropenem. All other patients survived and were either discharged home or moved to other hospitals/wards in good clinical condition. ESBL-KP ST45 was found in all isolates by multilocus sequence typing (MLST) analysis. An outbreak control plan was set, including surveillance cultures for all neonates, NICU environments, and medical devices, along with the extended use of contact precautions and cohorting. In addition, the infection control plan was carried out through reinforcement and enhancement measures to guarantee maximal compliance. The outbreak was successfully controlled in seven days, given that no further cases were identified after 9 February. The source of the ESBL-KP outbreak was not identified through environmental sampling. Thanks to multidisciplinary management, a threatening outbreak of ESBL-KP in a NICU was controlled in few days. The prompt recognition of the event onset and the adoption of infection control interventions helped contain the bacteria spread on the ward.

Whole Genome Sequencing of Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae Isolated from Neonatal Bloodstream Infections at a Neonatal Care Unit, Algeria

Aims: Neonatal bloodstream infections (BSIs) are an important cause of mortality among neonates. Besides, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) is one of the most frequent pathogens causing neonatal BSIs. This study aimed to characterize ESBL-Kp strains recovered from neonatal BSI and to investigate risk factors associated with ESBL-Kp BSI at the neonatal care unit of Elmeki Hospital, Bejaia, Algeria. Methodology: After isolation, identification, and antibiotic susceptibility testing, the ESBL-Kp strains were characterized by whole genome sequencing. The genomes were then analyzed using bioinformatic tools to determine the resistome, virulome, and phylogenetic relatedness. Results: From September 2019 to May 2020, 27 (8.2%) out of 328 neonates were infected by ESBL-Kp strains. These strains displayed a multidrug-resistant phenotype, and on further investigation, were found to carry an array of antibiotic resistance genes. All ESBL-Kp strains harbored the blaCTX-M-15 gene. Using in silico multilocus sequence typing analysis, six sequence types (STs) were detected with ST268 being the most frequent (56%, n = 15) indicating a local outbreak, confirmed by single nucleotide polymorphism analysis. The yersiniabactin and colibactin gene clusters were identified in six and two ESBL-Kp strains, respectively. Conclusion: This study showed a high prevalence of CTX-M-15-producing K. pneumoniae strains coharboring different antibiotic resistance mechanisms from neonatal BSIs in Algeria. Screening of health care personnel and mothers for ESBL carriage before delivery, isolation of carriers, barrier precautions, antimicrobial usage, and control of hygiene are needed to prevent the dissemination of these pathogens.

Prevalence and antimicrobial susceptibility profiles of ESBL-producing Klebsiella Pneumoniae from broiler chicken farms in Shandong Province, China

Klebsiella pneumoniae (K. pneumoniae) is a conditionally pathogenic bacterium present in the intestinal or the respiratory tract of animals, and it is a common factor in acquired infections and a major threat to public health. Increased production of extended-spectrum β-lactamases (ESBLs) has become a serious issue in the treatment of K. pneumoniae infections. In this study, we examined the serotypes and antibiotic resistance profiles of K. pneumoniae isolated from broiler chickens on farms in Shandong Province, China. The K. pneumoniae isolation rate was 4.67% (33/707), and the serotype Capsular K54 (42.42%, 14/33) was the most prevalent serotype in broilers in Shandong. The antimicrobial susceptibility assay revealed that the 33 isolates were resistant to 28 antimicrobial drugs to varying degrees; among these, the highest resistance rate was observed for tetracyclines (90.91%), and the lowest rate of resistance was observed for moxifloxacin and fosfomycin (0%). The multidrug resistance (MDR) rate was 87.88% (29/33). The carrying rate of β-lactam-resistance genes was as high as 100%, with blaSHV having the highest rate (93.94%). It is worth noting that one carbapenem-resistant K. pneumoniae (CRKP) isolate carrying blaNDM-1 and one colistin-resistant K. pneumoniae (COLR-KP) isolate carrying mcr-3 were found in broiler chickens. This study indicates that ESBL-producing CRKP isolates and COLR-KP isolates have emerged on poultry farms in Shandong and could be a potential threat to food safety and public health.

Populations of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae are different in human-polluted environment and food items: a multicentre European study

ObjectivesTo assess the extent to which food items are a source of extended-spectrum β-lactamase (ESBL) -producing Escherichia coli (ESBL-Ec) and ESBL-producing Klebsiella pneumoniae (ESBL-Kp) for humans in five European cities. MethodsWe sampled 122 human polluted (hp)-environments (sewers and polluted rivers, as a proxy of human contamination) and 714 food items in Besançon (France), Geneva (Switzerland), Sevilla (Spain), Tübingen (Germany) and Utrecht (The Netherlands). A total of 254 ESBL-Ec and 39 ESBL-Kp isolates were cultured. All genomes were fully sequenced to compare their sequence types (ST) and core genomes, along with the distribution of blaESBL genes and their genetic supports (i.e. chromosome or plasmid). ResultsSequence data revealed that ESBL-Ec and ESBL-Kp isolates from hp-environments were genetically different from those contaminating food items. ESBL-Ec ST131 was widespread in the hp-environment (21.5% of the isolates) but absent from the food items tested. ESBL-Ec ST10 was in similar proportions in hp-environments and food items (15 and 10 isolates, respectively) but mostly carried reservoir-specific blaESBL. blaCTX-M-1 and blaSHV-12 predominated in food-related E. coli isolates (32% and 34% of the isolates, respectively), whereas blaCTX-M-15 and blaCTX-M-27 predominated in isolates from hp-environments (52% and 15% of the isolates, respectively). ConclusionsWe found a very limited connection between ESBL-Ec and ESBL-Kp populations retrieved in food items and from hp-environments and blaESBL. This suggests that human-to-human contamination, rather than the food chain, is possibly the most frequent route of ESBL-Ec and ESBL-Kp transmission in high-income countries.

Investigation of Outbreaks of Extended-Spectrum Beta-Lactamase-Producing Klebsiella Pneumoniae in Three Neonatal Intensive Care Units Using Whole Genome Sequencing.

Infections caused by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) are on a constant rise and are a noted cause of outbreaks in neonatal intensive care units (NICUs). We used whole genome sequencing (WGS) to investigate the epidemiology of consecutive and overlapping outbreaks caused by ESBL-KP in NICUs in three hospitals in close proximity. Clonality of 43 ESBL-KP isolates from 40 patients was determined by BOX-PCR. Short-read sequencing was performed on representative isolates from each clone. The dominant clones from each NICU were sequenced using long-read sequencing. Bioinformatics methods were used to define multilocus sequence type (MLST), analyze plasmid content, resistomes, and virulence factors. In each NICU, we found a unique dominant clone (ST985, ST37, and ST35), each belonging to a distinct sequence type (ST), as well as satellite clones. A satellite strain in NICU-2 (ST35) was the dominant strain in NICU-3, where it was isolated four weeks later, suggesting transmission. NICU-1- and NICU-2-dominant strains had blaCTX-M-15 carried on a similar transposable element (Tn3-ISEcp1) but at different locations: on a plasmid and on the chromosome, respectively. We concluded that the overlapping ESBL-KP outbreaks were a combination of clonal transmission within NICUs, possible transposable element transmission between NICUs, and repeated importation of ESBL-KP from the community.

Ventilator-associated Pneumonia: Multidrug Resistant Acinetobacter vs. Extended Spectrum Beta Lactamase-producing Klebsiella.

Ventilator-associated pneumonia (VAP) has been considered as a healthcare-associated infection with high mortality. Acinetobacter baumannii and Klebsiella pneumoniae are the common causes of VAPs around the world. This research was a retrospective observational study in the intensive care unit (ICU) in a tertiary referral collegiate hospital in Tehran between March 2016 and May 2018. Patients who fulfilled VAP due to documented Multidrug Resistant Acinetobacter baumannii (MDR-AB) or Extended Spectrum Beta Lactamase-producing Klebsiella pneumoniae (ESBL-KP) criteria were enrolled. General demographic features, duration of hospital stay, antimicrobial treatment regimens, duration of ICU admission, the period of mechanical ventilation (MV) and 30-day mortality were documented and compared. 210 patients were found with clinical, microbiological and radiological evidence of VAP. In total, 76 patients with MDR-AB and 76 patients with ESBL-KP infections were matched in the final analysis. Duration of hospitalization in the patients with MDR-AB was significantly more than that of patients infected with ESBL-KP (p-value: 0.045). Patients diagnosed with MDR-AB VAP had a 65.8% mortality rate compared to 42.1% in the ESBL-KP infection group (p = 0.003). Results of the present study demonstrated that VAPs caused by MDR-AB may be more hazardous than ESBL-KP VAPs because they could be accompanied by a longer hospitalization course and even a higher mortality.

The utility of MALDI-TOF MS for outbreak investigation in the neonatal intensive care unit.

Our aim was to evaluate the performance of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), routinely used in the microbiology laboratory for bacterial identification, for bacterial typing in the setting of extended spectrum beta-lactamase producing Klebsiella pneumoniae (ESBL-KP) outbreak in the neonatal intensive care unit (NICU). Isolates from a 2011 outbreak in the NICU were retrieved from frozen stocks and analyzed by MALDI-TOF. The MALDI typing was compared with core genome multilocus sequence typing (cg-MLST). MALDI typing divided the 33 outbreak isolates into 2 clones: sequence type (ST)-290 and 405. These results were in complete agreement with cg-MLST results. The differentiation of the outbreak isolates into two clones correlated with the patients’ location in the NICU, but also with their place of residence.Conclusion: Here, we show that MALDI-TOF MS, which has been integrated into the microbiology laboratory workflow for microbial species identification, can be secondarily used for epidemiological typing at no added cost.What is Known:• Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is now routinely used in the microbiology laboratory for bacterial identificationWhat is New:• MALDI typing was used for outbreak investigation in the NICU and divided the outbreak isolates into two clones• MALDI-TOF MS may be secondarily used for epidemiological typing at no added cost.Electronic supplementary materialThe online version of this article (10.1007/s00431-020-03696-3) contains supplementary material, which is available to authorized users.

Fourier Transform Infrared Spectroscopy Is a New Option for Outbreak Investigation: a Retrospective Analysis of an Extended-Spectrum-Beta-Lactamase-Producing Klebsiella pneumoniae Outbreak in a Neonatal Intensive Care Unit.

The IR Biotyper is a new automated typing system based on Fourier-transform infrared (FT-IR) spectroscopy that gives results within 4 h. We aimed (i) to use the IR Biotyper to retrospectively analyze an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) in a neonatal intensive care unit and to compare results to BOX-PCR and whole-genome sequencing (WGS) results as the gold standard and (ii) to assess how the cutoff values used to define clusters affect the discriminatory power of the IR Biotyper. The sample consisted of 18 isolates from 14 patients. Specimens were analyzed in the IR Biotyper using the default analysis settings, and spectra were analyzed using OPUS 7.5 software. The software contains a feature that automatically proposes a cutoff value to define clusters; the cutoff value defines up to which distance the spectra are considered to be in the same cluster. Based on FT-IR, the outbreak represented 1 dominant clone, 1 secondary clone, and several unrelated clones. FT-IR results, using the cutoff value generated by the accompanying software after 4 replicates, were concordant with WGS for all but 1 isolate. BOX-PCR was underdiscriminatory compared to the other two methods. Using the cutoff value generated after 12 replicates, the results of FT-IR and WGS were completely concordant. The IR Biotyper can achieve the same typeability and discriminatory power as genome-based methods. However, to attain this high performance requires either previous, strain-dependent knowledge about the optimal technical parameters to be used or validation by a second method.

Successful control of an extended-spectrum beta-lactamase-producing Klebsiella pneumoniae ST307 outbreak in a neonatal intensive care unit

BackgroundIn this study, we evaluated the genetic relatedness of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KPN) isolates from an outbreak in a neonatal intensive care unit (NICU) in August 2017, We implemented an active countermeasure to control this outbreak successfully.MethodsThe incidence of healthcare-associated ESBL-KPN bacteremia was evaluated before and after initiating enhanced infection control (IC) practices in January 2018. Surveillance cultures were set up and monitored for neonates, medical personnel, and NICU environments. Molecular analyses, including pulse-field gel electrophoresis (PFGE), sequence typing, and ESBL genotyping, were performed for the isolated KPN strains.ResultsAfter implementing the enhanced IC procedures, the healthcare-associated bacteremia rate decreased from 6.0 to 0.0 per 1000 patient-days. Samples from neonates (n = 11/15, 73.3%), medical personnel (n = 1/41, 2.4%), and medical devices and the environments (6/181, 3.3%) tested positive for ESBL-KPN in the surveillance cultures in December 2017. Active surveillance cultures revealed that 23 of 72 neonates who were screened (31.9%) were colonized with ESBL-KPN between January and March 2018. All the isolates demonstrated closely related PFGE patterns and were identified as ST307 strain carrying the CTX-M-15 gene.ConclusionsContaminated NICU environments and medical devices, as well as transmission by medical personnel, appeared to be the source of the outbreak of ESBL-KPN infection. We employed an enhanced IC strategy during January–March 2018 and successfully controlled the clonal outbreak of CTX-M-15-positive KPN. ST307 has emerged as an important bacteremia-causing pathogen in the NICU and should be carefully monitored.

Characteristics and Clinical Outcomes of Extended-Spectrum beta-lactamase-producing Klebsiella pneumoniae Bacteremia in Cancer Patients.

BackgroundCancer patients can be at a higher risk of infection due to drug-resistant bacteria than the general population for various reasons. We performed a retrospective study to evaluate possible risk factors and outcomes of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) bacteremia in cancer patients.Materials and MethodsCases were divided into two groups based on whether or not the isolated strain produced ESBL and multivariable regressions were done to identify possible risk factors of ESBL-KP bacteremia and mortality. For ESBL-producing strain, additional molecular analysis was done.Results278 cases with KP bacteremia were identified between 2010 and 2012, of which ESBL-producers were 50 (18%). The presence of percutaneous drainage catheter [odds ratio (OR) 4.99, P <0.001] and prior exposure to certain classes of antibiotics including third-generation cephalosporin (OR 2.14, P = 0.03) had significant associations with ESBL-KP bacteremia. Individuals who died within 14 days after the onset of KP bacteremia were more likely to have higher mean Pitt bacteremia score (1.56 in survival group vs. 3.43 in mortality group, P <0.001), hemodialysis (OR 17.03, P = 0.01) and chronic liver disease (OR 5.57, P = 0.01). Although 14-day mortality was higher with ESBL production (OR 2.76, P = 0.04), no significant differences in 30-day mortality (OR 1.67, P = 0.20) and other morbidity indices were observed. 49 ESBL-KP isolates, 65.4% of them produced CTX-M-14 and CTX-M-15 enzymes, and ST711 was the most common.ConclusionThere were several differences in clinical characteristics between ESBL-KP and non-ESBL-KP bacteremia in cancer patients, similar to previous reports including non-cancer patients.

Antibacterial Effect of Streptomyces sp-MWS1, Streptomyces sp-MWS3, and Streptomyces sp-MWS6 ON Klebsiella pneumoniae Producting Extended-Spectrum β-Lactamase (ESBL)

Klebsiella pneumoniae as an opportunistic pathogen can cause nosocomial infection. The main concern on this bacterium is directed on the extended-spectrum β-Lactamase (ESBL)-producing Klebsiella pneumoniae. The therapy of ESBL-producing Klebsiella pneumoniae infections is very limited because of its multidrug resistance. It had been found new local isolates Streptomyces sp-MWS1, Streptomyces sp-MWS3, and Streptomyces sp-MWS6 in mangrove East Coast of Surabaya. These isolates have potential to produce antibiotics (Retnowati, 2008). This study was aimed to prove these isolates may inhibit the growth of ESBL-producing Klebsiella pneumonia.&#x0D; The test of antibacterial activity of Streptomyces sp-MWS1, Streptomyces sp-MWS3, and Streptomyces sp-MWS6 using the modification Agar print method against clinical isolates of ESBL-producing Klebsiella pneumoniae. The diameter of inhibition zone (mm) formed shows activity of these isolates.&#x0D; The profiles of antibacterial activity of Streptomyces sp-MWS1, Streptomyces sp-MWS3, and Streptomyces sp-MWS6 were different in terms of periode required to reach peak activity, duration of activity and inhibition zone diameter produced during 10 days of observation. Streptomyces sp-MWS3 reached the peak activity most rapidly on day 3 with the largest inhibition zone diameter of 9 mm in ESBL-producing Klebsiella pneumoniae.&#x0D; There were significant differences in inhibition zone diameter between Streptomyces sp-MWS1, Streptomyces sp-MWS3, and Streptomyces sp-MWS6 against ESBL-producing Klebsiella pneumoniae.

2282. Empiric Antimicrobial Therapy and Clinical Outcomes of Infections due to ESBL-producing Klebsiella pneumoniae

BackgroundCurrently, carbapenems are the treatment of choice for invasive infection due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E). However, clinical data supporting this practice are generated largely from cases caused by ESBL-producing Escherichia coli. We aimed to describe the empiric treatments and clinical outcomes of patients infected with ESBL-producing Klebsiella pneumoniae (ESBL-Kp) at UPMC Presbyterian Hospital in Pittsburgh, PA.MethodsThis retrospective study included all adult patients from inpatient admissions at UPMC Presbyterian Hospital who were diagnosed with ESBL-Kp infections. Carbapenem-resistant cases were excluded. Types of cultures included blood, respiratory, urine, and wound. Only one type of culture per patient was included. Demographic and clinical data were collected from the electronic medical records. The study was approved by the University of Pittsburgh IRB.ResultsOne-hundred sixty-four patients had ESBL-Kp infection between September 2016 and August 2018. Excluded were those who were considered colonized by the organism and therefore not treated (n = 15); treated with non-carbapenems as definitive therapy (n = 29); or were discharged before final susceptibilities (n = 14). In total, 70 patients met inclusion criteria. Eighteen had bacteremia, 24 had pneumonia, 13 had UTI, and 12 had wound infections. Most common sources of bacteremia included catheter-associated, intra-abdominal infection, and pneumonia. Median age of patients was 62 years. Mean Charleston Comorbidity Index was 4.6. Empiric treatment was divided between three classes: BL-BLI (n = 27, 38.6%), cephalosporins (n = 21, 30%) and carbapenems (n = 18, 25.7%). Twelve patients (17.1%) died during hospitalization. Average hospital length-of-stay was 33.2 days.ConclusionAlthough infections with ESBL-Kp are relatively uncommon, patients have high mortality and prolonged hospitalizations. Treatment practices, including which infections are considered colonization vs. true infection, as well as choice of empirical therapy, vary widely at our institution. Data are still needed to assess mortality outcomes in patients treated empirically with carbapenems vs. non-carbapenems, particularly in high-inoculum infection sites such as pneumonia. Disclosures All authors: No reported disclosures.

Performance comparison of the fast track diagnostics multiplex real-time PCR assays on two different automated molecular platforms

Minim typing is derived from the multi-locus sequence typing (MLST). It targets the same genes, but sequencing is replaced by high resolution melt analysis. Typing can be performed by analysing six loci (6MelT), four loci (4MelT) or using data from four loci plus sequencing the tonB gene (HybridMelT). The aim of this study was to evaluate Minim typing to discriminate extended-spectrum beta-lactamase producing Klebsiella pneumoniae (ESBL-KLPN) isolates at our hospital. In total, 380 isolates were analyzed. The obtained alleles were assigned according to both the 6MelT and 4MelT typing scheme. In 97 isolates, the tonB gene was sequenced to enable HybridMelT typing. We found that the presented method is suitable to quickly monitor isolates of ESBL-KLPN; results are obtained in less than 2 hours and at a lower cost than MLST. We identified a local ESBL-KLPN outbreak and a comparison of colonizing and invasive isolates revealed a long term colonization of patients with the same strain.

Which non-carbapenem antibiotics are active against extended-spectrum β-lactamase-producing Enterobacteriaceae?

In this study, the activity of 18 non-carbapenem antibiotics was evaluated against 100 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-Ec) and 50 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) isolated from urinary tract infections and bacteraemia in 2016. Minimum inhibitory concentrations (MICs) were determined using reference methods and the susceptibility profiles were defined according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2017 recommendations. All of the ESBL-Ec isolates were susceptible to ceftazidime/avibactam and a great majority of them were susceptible to fosfomycin (98%), piperacillin/tazobactam (97%), amikacin (97%) and nitrofurantoin (96%). Mecillinam, cefoxitin and ceftolozane/tazobactam remained active against 92%, 83% and 78% of the ESBL-Ec isolates, respectively. Moreover, 100%, 94% and 90% of the ESBL-Kp tested were susceptible to ceftazidime/avibactam, amikacin and mecillinam, respectively. This study showed that there are non-carbapenem options (including orally administrable drugs) for the treatment of all of the situations of ESBL-Ec or ESBL-Kp infections, with ceftazidime/avibactam being the most efficient alternative.

Antibiotic-dependent perturbations of extended spectrum beta-lactamase producing Klebsiella pneumoniae proteome.

Extended spectrum beta-lactamase producing Klebsiella pneumoniae (ESBL-KP) causes life-threatening infections in susceptible and immuno-compromised individuals. Because of the emergence of multidrug resistance and tolerance, it is crucial to better understand the mechanisms by which ESBL-KP can adapt to antibiotic stress. The aim of this study was to provide an overview of the global proteome changes occurring in ESBL-KP in response to sub-lethal concentrations of the antibiotics doxycycline (DC, bacteriostatic) and streptomycin (SM, bactericidal), which both impair ribosomal synthesis of bacterial proteins. These results represent the greatest experimental coverage of the ESBL-KP proteome yet described. The 1538 proteins, representing 30% of the 5126 predicted KP gene products were identified from the combined experimental groups. Antibiotic stress resulted in significantly elevated levels of 42 proteins for DC and 55 for SM treatments, whereas 53 proteins were reduced for DC- and six for SM-treated bacteria. Specifically, the ESBL-KP response to DC was accompanied by the reduced levels of the porins LamB, CirA, FepA, and OmpC. In contrast to DC, the stress response to SM demonstrated a dramatic increase in the peroxidase detoxification pathway proteins PutA, KatG, KatE, and Dps, which prevent harmful hydroxyl radical formation. The results from this proteomic study are important for understanding adaptive responses to antibiotics, and may provide novel targets for the development of new therapeutic strategies.