[The threat of the carbapenemase-producing enterobacteriaceae in Spain: positioning report of the SEIMC study groups, GEIH and GEMARA]

Studies in vitro and in vivo of phage therapy medical products (PTMPs) Targeting Clinical Strains of Klebsiella pneumoniae belonging to the clone ST512

The widespread incidence of antimicrobial resistance has created renewed interest in the use of alternative antimicrobial treatments such as phage therapy. Phages are viruses that infect bacteria and generally have a narrow bacteria host-range. Combining phages with antibiotics can prevent the emergence of bacterial resistance. The aim of the present study was to develop phage therapy medical products (PTMPs) targeting clinical isolates of carbapenem-producing Klebsiella pneumoniae belonging to the high-risk clone ST512. From a collection of 22 seed of lytic phages sequenced belonging to MePRAM collection (Spanish Health Precision Medicine Project against Antimicrobial Resistance), four were used to generate PTMPs (CAC_Kpn1 and CAC_Kpn2). These PTMPs were partly active against three of the clinical strains of clone ST512 (A, B, and C). The use of Appelmans method in the CAC_Kpn1_ad (adapted CAC_Kpn1) yielded a significant increase in the efficacy against strain A, while adapted CAC_Kpn2 (CAC_Kpn2_ad) only effectively reduced bacterial survival when combined with ½ × MIC ß-lactam antibiotic meropenem for 24 h in clinical strains B and C, showed after this time, resistance to PTMPs. In addition, the amounts of endotoxin released by the PTMPs were quantified and subsequently reduced in preparation for in vivo use of the PTMPs in the Galleria mellonella infection model, confirming the in vitro results from the CAC_Kpn1_ad and CAC_Kpn2_ad. To sum up, the preparation of two PTMPs and their subsequent adaptation can be a good approach to solve part of the occurrence of antimicrobial resistance. In addition, the use of the larval model is an effective method to discriminate the efficacy of in vivo treatment.

CRISPR-Cas13a-Based Assay for Accurate Detection of OXA-48 and GES Carbapenemases

Carbapenem-resistant pathogens have been recognized as a health concern as they are both difficult to treat and detect in clinical microbiology laboratories. Researchers are making great efforts to develop highly specific, sensitive, accurate, and rapid diagnostic techniques, required to prevent the spread of these microorganisms and improve the prognosis of patients. In this context, CRISPR-Cas systems are proposed as promising tools for the development of diagnostic methods due to their high specificity; the Cas13a endonuclease can discriminate single nucleotide changes and displays collateral cleavage activity against single-stranded RNA molecules when activated. This technology is usually combined with isothermal pre-amplification reactions in order to increase its sensitivity. We have developed a new LAMP-CRISPR-Cas13a-based assay for the detection of OXA-48 and GES carbapenemases in clinical samples without the need for nucleic acid purification and concentration. To evaluate the assay, we used 68 OXA-48-like-producing Klebsiella pneumoniae clinical isolates as well as 64 Enterobacter cloacae complex GES-6, 14 Pseudomonas aeruginosa GES-5, 9 Serratia marcescens GES-6, 5 P. aeruginosa GES-6, and 3 P. aeruginosa (GES-15, GES-27, and GES-40) and 1 K. pneumoniae GES-2 isolates. The assay, which takes less than 2 h and costs approximately 10 € per reaction, exhibited 100% specificity and sensitivity (99% confidence interval [CI]) for both OXA-48 and all GES carbapenemases. IMPORTANCE Carbapenems are one of the last-resort antibiotics for defense against multidrug-resistant pathogens. Multiple nucleic acid amplification methods, including multiplex PCR, multiplex loop-mediated isothermal amplification (LAMP) and multiplex RPAs, can achieve rapid, accurate, and simultaneous detection of several resistance genes to carbapenems in a single reaction. However, these assays need thermal cycling steps and specialized instruments, giving them limited application in the field. In this work, we adapted with high specificity and sensitivity values, a new LAMP CRISPR-Cas13a-based assay for the detection of OXA-48 and GES carbapenemases in clinical samples without the need for RNA extraction.

Implementation and impact of an antibiotic control program and multidrug-resistant bacterial colonization in a liver transplant unit

INTRODUCTION

infections by multidrug-resistant bacteria are a major cause of morbidity and mortality in transplant patients.

OBJECTIVE

a retrospective single-center study was performed to evaluate the implementation of an Antimicrobial Treatment Optimization Program (PROA) on multidrug-resistant bacteria colonization and infection after liver transplant (LT).

METHODS

colonization by multidrug-resistant bacteria and infections during the first year after a liver transplant were analyzed in a group of 76 transplanted patients in two stages, before and after PROA (2016-2019). Clinical variables related to infection, readmissions and survival one year after the liver transplant were analyzed.

RESULTS

there was good adherence to the PROA. Infection was the most frequent cause for readmission during the first year after the liver transplant. Incidence of infections was similar during both periods (mean of 1.25 and 1.5 episodes of bacterial infection per patient/year, respectively) with 19 bacterial infectious episodes, six by hospital-acquired multidrug-resistant and extensively drug-resistant (MDR-XDR) bacteria in the pre-PROA stage, and 18 bacterial infectious episodes, five by MDR-XDR in the post-PROA stage. A 37 % decrease of post-TH of rectal colonization by MDR-XDR after liver transplant was observed during 2019.

CONCLUSIONS

epidemiological surveillance policies and antibiotic optimization are key to control the increase of colonization and infection by multidrug-resistant bacteria in liver transplant units. Long-term studies are needed to better evaluate the impact of these programs.

Interhospital dissemination of KPC-3 producing-Klebsiella pneumoniae ST512. Detection by MALDI-TOF

INTRODUCTION/OBJECTIVE

To describe an outbreak of KPC-3-producing Klebsiella pneumoniae (KPN) and determine the diagnostic efficacy of MALDI-TOF in its detection.

METHODS

Retrospective study of the KPC-3-KPN isolated in 2 hospitals in Ciudad Real. The peak at 11,109kDa±15 was sought in the KPN spectra provided by MALDI-TOF.

RESULTS

We isolated 156 KPN strains that carried the bla_KPC-3 gene, with a unique profile belonging to ST512 (31 strains studied). There was 25% of infected patients, 84% were nosocomial or related to health care and 93% had some underlying disease (31% of exitus in the first month). The detection of the peak showed 90% sensitivity and 100% specificity.

CONCLUSIONS

We detected the clonal spread of a KPN ST512 strain producing KPC-3 in 3 hospitals in Ciudad Real. In addition, we show the profitability of MALDI-TOF in the early detection of KPC-KPN.

Surgeon-led 7-VINCut Antibiotic Stewardship Intervention Decreases Duration of Treatment and Carbapenem Use in a General Surgery Service

Antibiotic stewardship programs optimize the use of antimicrobials to prevent the development of resistance and improve patient outcomes. In this prospective interventional study, a multidisciplinary team led by surgeons implemented a program aimed at shortening the duration of antibiotic treatment <7 days. The impact of the intervention on antibiotic consumption adjusted to bed-days and discharges, and the isolation of multiresistant bacteria (MRB) was also studied. Furthermore, the surgeons were surveyed regarding their beliefs and feelings about the program. Out of 1409 patients, 40.7% received antibiotic therapy. Treatment continued for over 7 days in 21.5% of cases, and, as can be expected, source control was achieved in only 48.8% of these cases. The recommendations were followed in 90.2% of cases, the most frequent being to withdraw the treatment (55.6%). During the first 16 months of the intervention, a sharp decrease in the percentage of extended treatments, with R2 = 0.111 was observed. The program was very well accepted by surgeons, and achieved a decrease in both the consumption of carbapenems and in the number of MRB isolations. Multidisciplinary stewardship teams led by surgeons seem to be well received and able to better manage antibiotic prescription in surgery.

Characterization of carbapenemase-producing Enterobacteriaceae from colonized patients in a university hospital in Madrid, Spain, during the R-GNOSIS project depicts increased clonal diversity over time with maintenance of high-risk clones

Objectives

To describe the incidence and microbiological features of carbapenemase-producing Enterobacteriaceae (CPE) from colonized patients in a Spanish university hospital during a cluster-randomized study [the Resistance of Gram-Negative Organisms: Studying Intervention Strategies (R-GNOSIS) project] on isolation strategies for faecal ESBL carriers.

Methods

From March 2014 to March 2016, 15 556 rectal swabs from 8209 patients admitted in two surgical wards and two medical wards were collected and seeded on ESBL and CPE chromogenic agars. Carbapenemase characterization (PCR and sequencing) was performed, and antibiotic susceptibility (MIC), clonality (PFGE and MLST) and diversity (Simpson diversity index estimation) were determined.

Results

One hundred and ninety-eight CPE isolates, mainly Klebsiella pneumoniae (53.5%) and Escherichia coli (19.2%), were identified in 162 patients (2%). Prevalence of CPE carriage remained unchanged over time. Overall, amikacin (9.6%), tigecycline (9.6%) and colistin (0.5%) showed low non-susceptibility. The most frequent carbapenemase was OXA-48 (64.1%), followed by VIM-1 (26.8%), NDM-1 (5.3%) and KPC-3 (3.5%), and these were co-produced with ESBLs in 43.9%. OXA-48 plus CTX-M-15 was the most frequent association. Two major K. pneumoniae clones were identified (OXA-48-CTX-M-15-ST11 and VIM-1-SHV-12-ST54) with considerable genetic diversity among the remaining isolates, including OXA-48-E. coli. Species diversity tended to decrease from 0.75 in the first 6 months of the study to 0.43 in the final months. The emergence of new clones (i.e. OXA-48-Kluyvera spp. and NDM-1-K. pneumoniae ST437 and ST101) and displacement of other particular clones were also demonstrated.

Conclusions

We describe a polyclonal and changeable CPE population over time. Coexistence of worldwide disseminated clones, such as ST11-OXA-48- K. pneumoniae, with unrelated and emerging OXA-48-E. coli clones, depicts a disturbing CPE epidemiology in our institution.

Prevalence and characterization of β-lactamase-producing Enterobacteriaceae in healthy human carriers

Presence of extended-spectrum β-lactamase (ESBL-E), AmpC-producing and carbapenemase-producing (CPE) Enterobacteriaceae has been observed not only in the clinical environment, but also in the out-of-hospital environment. The objective of this study was to isolate and characterize strains of ESBL, AmpC, and CPE present in feces of healthy carriers in Navarra (n = 125). Despite the fact that no CPE strains were isolated, 16% and 11.2% of the studied population were ESBL-E and AmpC carriers, respectively. No significant differences were found by gender or age; young people (5-18 years old) showed the highest ESBL-E prevalence (31.8%). The isolates corresponded to E. coli (57.1%), Enterobacter spp. (28.6%), and Citrobacter freundii (14.3%), and all strains showed multidrug-resistant profiles. High resistance against cephalosporins, penicillins, and monobactams, and sensitivity to carbapenems, quinolones, and aminoglycosides were observed. With respect to ESBL producers, 52.4% were CTX-M-type (19.0% CTX-M-14, 9.5% CTX-M-1, and 28.6% CTX-M-15) and 47.6% were TEM-type (38.1% TEM-171). These results confirm the extensive dissemination of these resistances among a healthy population and pose the need to implement control measures and strategies according to the One Health approach in order to prevent the increase of severe and untreatable infections in a not far future.

Description of carbapenemase-producing Enterobacteriaceae isolates in a Spanish tertiary hospital. Epidemiological analysis and clinical impact

OBJECTIVE

The aim of the study was to carry out an epidemiological analysis of patients with carbapenemase-producing Enterobacteriaceae (CPE) isolations in our hospital as well as to perform a description of the genotypic temporal evolution of CPE isolated.

METHODS

An observational prospective cohort study was performed involving all patients with CPE isolates from clinical samples during November 2014 to November 2016 in a Spanish teaching hospital. Patients were clinically evaluated and classified either as infected or colonized. Information on the consumption of carbapenems in the hospital during the study period was also analyzed. PCR was used for identification of the carbapenemase genes blaKPC, blaVIM, and blaOXA-48.

RESULTS

A total of 301 CPE isolates were obtained (107 in 2014, 89 in 2015 and 105 in 2016). Klebsiella pneumoniae (73.4%) was the most prevalent microorganism. Hundred and seventy (56.7%) of carbapenemases detected were blaOXA-48, 73 (24.3%) were blaKPC and 57 (19%) were blaVIM. In year 2014 KPC was predominant while in 2016 OXA-48 predominated. In 2014 we observed a significant association between the medical wards and the ICU with a higher prevalence of OXA-48 (OR 4.15; P<0.001) and VIM (OR 7.40; P<0.001) in the univariate analysis, in the following years there was no association. Regarding the clinical significance of microbiological results after assessing our patients, 60% of isolates represented infection and 40% behaved as colonizers. One third of hospitalized patients with CPE isolation died within 30 days, regardless of whether they were colonized or infected.

CONCLUSIONS

We have observed an epidemiological change in the genotypes of our isolates along the study period. A thorough knowledge of the CPE's epidemiological distribution in each hospital is fundamental for optimizing antimicrobial chemotherapy.

[Risk factors and clinical evolution of carbapenemase-producing Klebsiella pneumoniae infections in a university hospital in Spain. Case-control study]

OBJECTIVE

Carbapenemase-producing Enterobacterias is a global health hazard due to their ease of transmission, difficulty of treatment, and their personal and economic impact. We analyze the factors associated with an increased risk of infection by Klebsiella pneumoniae carbapenemase-producing bacteria (KPC) and factors related to poor prognosis.

METHODS

We designed a case-control study. KPC isolates were taken during an outbreak in a hospital in Madrid. A logistic regression was performed with the main variables.

RESULTS

Sixteen cases of clinically documented infections were isolated. Overall mortality rates in the cases group was 25%. The most frequent location was blood (37.5%) followed by urine (25%). All but one were OXA-48. Regarding factors related to an increased risk of developing infection, only previous exposure to antibiotics presented statistical significance difference OR 13 (2.40-70.46). With respect to the overall mortality, the presence of pneumonia OR 25 (1.93-323.55) or the use of invasive mechanical ventilation was associated with greater risk 15 OR 33 (1.92-122.8) For attributable mortality only invasive ventilation had a significant association OR 18 (1.48-218.95).

CONCLUSIONS

Exposure to previous antibiotics is an independent risk factor for developing KPC infection, adjusted for all other clinical and demographic variables. Risk factors such as the presence of pneumonia or the use of invasive mechanical ventilation were associated with a worse prognosis in terms of overall and attributable mortality.

Infections by carbapenemase-producing enterobacteriaceae in a department of urology. A new challenge

OBJECTIVES

To analyse infections by carbapenemase-producing enterobacteriaceae (CPE) and describe the characteristics and potential risk factors associated with patients of a department of urology.

MATERIAL AND METHODS

Observational and retrospective study. The inclusion criterion was hospitalisation in our department of Urology between August 2013 and December 2016. We analysed those patients who were positive for CPE in at least 1 culture. We reviewed their baseline characteristics, risk factors and variables such as the presence of previous urinary tract infections, subsequent readmissions, the microorganism, type of CPE, treatment, origin (hospital or community) and mortality.

RESULTS

Of the 5,657 patients who met the inclusion criterion, a CPE was isolated in 12 cases. CPE infections represented 3.6% of all healthcare-associated infections and 9.7% of those caused by enterobacteria. The analysed factors associated with CPE infection in our series were the presence of urinary catheters (100%), undergoing surgery (58.3%), previous ICU admission (8.3%) and immunosuppression (16.6%). In terms of mortality, 8.3% of the patients who presented CPE infection died during hospitalisation.

CONCLUSIONS

Approximately 10% of enterobacteria present a carbapenemase-resistance pattern in urological patients in our setting. Carrying a urinary catheter and/or undergoing surgery are risk factors associated with the development of these infections in urological patients in our setting. CPE infections increase morbidity and mortality.

Risk factors for colonization by carbapenemase-producing enterobacteria at admission to a Surgical ICU: A retrospective study

INTRODUCTION

In 2011, a hospital-wide outbreak of OXA-48 producing Klebsiella pneumoniae occurred in our hospital, an epidemiological setting of high ESBL-producing K. pneumoniae rates. This study identifies risk factors for colonization with carbapenemase-producing enterobacteria (CPE) at Surgical Intensive Care Unit (SICU) admission.

METHODS

A 2-year retrospective study was performed in all patients admitted to the SICU that following routine had a rectal swab collected upon admission.

RESULTS

Of 254 patients admitted, 41 (16.1%) harbored CPE (five showing two carbapenemase-producing isolates). Most frequent carbapenemase-producing isolates and carbapenemases were K. pneumoniae (39/46, 84.8%) and OXA-48 (31/46; 76.1%), respectively. Carriers significantly had higher rates of chronic renal disease, previous digestive/biliary endoscopy, hospitalization, ICU/SICU admission, intraabdominal surgery, and antibiotic intake, as well as higher median values of clinical scores (SOFA, SAPS II and APACHE II). In the multivariate analysis (R²=0.309, p<0.001), CPE carriage was associated with prior administration of 3rd-4th generation cephalosporins (OR=27.96, 95%CI=6.88, 113.58, p<0.001), β-lactam/β-lactamase inhibitor (OR=11.71, 95%CI=4.51, 30.43, p<0.001), abdominal surgery (OR=6.33, 95%CI=2.12, 18.89, p=0.001), and prior digestive/biliary endoscopy (OR=3.88, 95%CI=1.56, 9.67, p=0.004).

CONCLUSIONS

A strong association between production of ESBLs and carriage of CPE (mainly OXA-48 producing K. pneumoniae) was found. According to the model, the co-selection of β-lactamases by previous exposure to broad-spectrum cephalosporins and β-lactam/β-lactamase inhibitors (with lower relative risk), abdominal surgery and prior digestive/biliary endoscopy were factors associated with CPE carriage.

Molecular characterization of blaNDM-5 carried on an IncFII plasmid in an Escherichia coli isolate from a nontraveler patient in Spain

A carbapenem-resistant Escherichia coli isolate (sequence type 448 [ST448]) was recovered from a urine culture of a female patient with no recent record of traveling. PCR screening identified the presence of bla(NDM-5), bla(TEM-1), bla(OXA-1), bla(CMY-42), and rmtB. bla(NDM-5) was carried in a conjugative IncFII-type plasmid (90 kb) together with bla(TEM-1) and rmtB. The genetic environment of bla(NDM-5) showed a structure similar to those of pMC-NDM and pGUE-NDM, identified in Poland and France in E. coli of African and Indian origin, respectively.