Emergence and clonal expansión of Klebsiella pneumoniae ST307, simultaneously producing KPC-3 and NDM-1

Abstract MDR Klebsiella pneumoniae ST307 is a high-risk clone, whose genetic features contribute to its adaptation to hospital environments and the human host. This study describesthe emergence and clonal dissemination of K. pneumoniae ST307, recovered during November2018 to February 2019 in a hospital in Buenos Aires city, which concurrently harbored KPC-3and NDM-1. These isolates were resistant to all -lactams and to the ceftazidime/avibactamcombination. Molecular studies showed that blaKPC-3was located in Tn4401a platform, whileblaNDM-1was surrounded upstream by ISKpn14 followed by a partial sequence of ISAba125 anddownstream by bleMBL-trpF, located in a 145.5 kb conjugative plasmid belonging to the Inc A/Cgroup. The dissemination of K. pneumoniae ST307 isolates co-producing KPC-3 and NDM-1 couldlead to a worrisome scenario due to the remarkable features of this clone and its resistanceprofile.

Resumen Klebsiella pneumoniae ST307 es un clon de alto riesgo, cuyas características genéticas contribuyen a su adaptación al entorno hospitalario y al huésped humano. Este estudio describe la emergencia y diseminación clonal de aislamientos de K. pneumoniae ST307 productores de KPC-3 y NDM-1, recuperados en un hospital de Buenos Aires. Estos aislamientos fueron resistentes a todos los p-lactámicos y a la combinación ceftacidima/avibactam. Los estudios moleculares evidenciaron que el contexto genético de blaKPC-3 se correspondió con el Tn4401a, mientras que blaNDM-1 estuvo flanqueado corriente arriba por ISKpn14 y una secuencia parcial de ISAba125 y corriente abajo por bleMBL - trpF, localizado a su vez en un plásmido conjugativo de 145.5 kb perteneciente al grupo Inc A/C. La emergencia de aislamientos de K. pneumoniae ST307 coproductores de KPC-3 y NDM-1 pone de manifiesto una situación altamente preocupante debido a las características de este clon y a su perfil de multirresistencia.

Clinical practice guideline for screening of patients at risk of colonization by carbapenemase-producing Enterobacterales and the treatment of infections caused by these bacteria / Guía de práctica clínica para la tamización de pacientes con riesgo de colonización por Enterobacterales productores de carbapenemasasy el manejo de infecciones causadas por estas bacterias

Abstract Carbapenemase-producing Enterobacterales (CPE) infections have increased in recent years. Colombia has become an endemic country for this group of microorganisms, and the infections they cause have a serious impact in terms of morbidity and mortality. The early identification of CPE carriers who are admitted to health care centers as patients is necessary to implement adequate isolation and infection control measures to limit the spread of this type of microorganisms in hospitals. Furthermore, treating these infections is a challenging task due to the limited therapeutic alternatives available and the fact that there are only a few studies proving their effectiveness in this setting. Therefore, the objective of the present work is to develop a clinical practice guideline (CPG) for the screening of patients at risk of CPE colonization and the treatment of inpatients with suspected or confirmed infections caused by this type of bacteria through a CPG adaptation process based on the ADAPTE methodology. With this purpose in mind, evidence-informed recommendations for the screening and timely identification of CPE carriers admitted to hospitals are made, as well as for the adequate pharmacological treatment of CPE infections in this context.

Resumen Las infecciones por Enterobacterales productores de carbapenemasas (EPC) han aumentado en los últimos años. Colombia se ha convertido en un país endémico para este grupo de microorganismos y las infecciones que causan tienen un impacto importante en términos de morbimortalidad. La identificación temprana de los portadores de EPC que ingresan como pacientes a las instituciones de salud es necesaria para implementar medidas de aislamiento y control de infecciones adecuadas que limiten la diseminación de este tipo de microorganismos en los hospitales. Además, el tratamiento de estas infecciones es difícil debido a las limitadas alternativas terapéuticas disponibles y la escasez de estudios que demuestren su efectividad en este escenario. Por lo anterior, el objetivo del presente trabajo es desarrollar una guía de práctica clínica (GPC) para la tamización de pacientes con riesgo de colonización por EPC y para el manejo de pacientes con infecciones, ya sea sospechadas o confirmadas, causadas por este tipo de bacterias, mediante un proceso de adaptación de GPC basado en la metodología ADAPTE. Con este propósito en mente, se hacen recomendaciones informadas en evidencia para realizar la tamización y oportuna identificación de portadores de EPC admitidos en instituciones hospitalarias, así como para el adecuado manejo farmacológico de las infecciones por CPE en este escenario.

In vitro antibacterial effects of imipenem combined with conventional antibiotics on bla KPC-2 type carbapenem resistant klebsiella pneumoniae / 中国基层医药

Objective:To investigate the in vitro antibacterial effects of imipenem combined with common antibiotics on bla KPC-2 type carbapenem resistant klebsiella pneumoniae (CRKP) targeting bla KPC-2 gene. Methods:Six strains of unrepeated bla KPC-2 type confirmed by polymerase chain reaction and DNA sequence were isolated in Yueqing People's Hospital, China between January 2018 and January 2019 were included in this study. The susceptibility rate of imipenem against nine conventionally used antibiotics was determined. The sensitivity test of imipenem combined with eight antibiotics was performed with the checkerboard method. Fractional inhibitory concentration was calculated to assess the efficacy of imipenem combined with common antibiotics. The in vitro treatment time-antibacterial effect curve was drawn to evaluate the antibacterial effects. Results:The resistance rate of six strains of bla KPC-2 type was 100.00% (6/6) for imipenem, meropenem, ceftazidime, ciprofloxacin, rifampicin and cefotaxime, and it was 66.67% (4/6) for minocycline and clavulanic acid and 33.33% (2/6) for tigecycline. Imipenem combined with tigecycline had a better antibacterial effect and exhibited a synergistic effect on four strains of bla KPC-2 type CRKP and an additive effect on two strains of Bla KPC-2 type CRKP. The curve of time for in vitro treatment of KPN2 with imipenem combined with tigecycline against bactericidal effect revealed that the antibacterial rate of imipenem at the 1/2 minimum inhibitory concentration combined with tigecycline at the 1/4 minimum inhibitory concentration was > 95% at (t+2) and the antibacterial effect could maintain (t+10) hours to (t+12) hours. The antibacterial rate of imipenem combined with tigecycline against strain 002 was gradually decreased with time, and the growth curve of strain 002 rised gradually. Conclusion:In vitro drug sensitivity test revealed that imipenem combined with tigecycline exhibits a good synergistic effect on bla KPC-2 type CRKP. Findings from this study provide a reference for clinical treatment of bla KPC-2 type CRKP.

Multirresistencia de Escherichia coli y Klebsiella pneumoniae provenientes de pacientes con infección del tracto urinario adquirida en la comunidad / Escherichia coli and Klebsiellap neumoniae multiresistance from patients with urinary tract infection acquired in the community

Introducción: El incremento de la multirresistencia bacteriana constituye un problema de salud pública a nivel internacional. Objetivos: Determinar la susceptibilidad antimicrobiana y los patrones de multirresistencia en cepas de Escherichia coli y Klebsiella pneumoniae aisladas de urocultivos. Métodos: Se realizó un estudio descriptivo retrospectivo en el Centro Municipal de Higiene, Epidemiología y Microbiología, municipio Güines, provincia Mayabeque, Cuba, en el periodo comprendido de enero a diciembre de 2017. El estudio incluyó 250 cepas de Escherichia coli y 62 de Klebsiella pneumoniae aisladas e identificadas de muestras de orina de pacientes con infección del tracto urinario adquirida en la comunidad. La susceptibilidad antimicrobiana fue evaluada con el método de difusión en agar empleado la técnica de Kirby Bauer. Resultados: En Escherichia coli se observó niveles de resistencia superiores al 60 por ciento a los antimicrobianos ácido nalidíxico, cefotaxima, trimetoprim - sulfametoxazol y ceftazidima. La nitrofurantoína y la amikacina presentaron 88,8 por ciento y 83,8 por ciento de efectividad, respectivamente. Se apreció en Klebsiella pneumoniae altos valores de resistencia a ceftazidima, trimetoprim - sulfametoxazol y ácido nalidíxico. Amikacina, presentó niveles de sensibilidad de un 71 por ciento. La resistencia a las cefalosporinas de tercera generación se detectó en 78 (31,2 por ciento) de Escherichia coli y 26 (41,9 por ciento) de Klebsiella pneumoniae. De los aislados de Escherichia coli 143 (57,2 por ciento) y Klebsiella pneumoniae 35 (56,4 por ciento) presentaron multidrogoresistencia. Conclusiones: Existe la circulación de cepas resistentes a cefalosporinas de tercera generación y multidrogorresistentes causantes de infecciones de las vías urinarias adquiridas en la comunidad y se informa sobre los antibióticos (nitrofurantoína y amikacina) que podrían ser utilizados para combatirlas de forma empírica en esta área geográfica(AU)

Introduction: The increase of bacterial multiresistance constitutes a public health problem at the international level. Objectives: To determine antimicrobial sensitivity and multiresistance patterns in strains of Escherichia coli and Klebsiellapneumoniae isolated from urine cultures. Methods: A retrospective, descriptive study was conducted at the Municipal Center for Hygiene, Epidemiology and Microbiology, Güines municipality, Mayabeque Province, Cuba, in the period from January to December, 2017. The study included 250 Escherichia coli and 62 Klebsiellapneumoniae strains isolated and identified from urine samples from patients with urinary tract infection acquired in the community. Antimicrobial sensitivity was evaluated with the method of diffusion in agar using Kirby Bauer´s technique. Results: In Escherichia coli, resistance levels higher than the 60% were observed in antimicrobial nalidixic acid, cefotaxime, trimethoprim-sulfamethoxazole and ceftazidime. Nitrofurantoin and amikacin presented 88.8 percent and 83.8 percent of effectiveness, respectively. High values of resistance to ceftazidime, trimethoprim-sulfamethoxazole and nalidixic acid were present in Klebsiellapneumoniae. Amikacin presented sensitivity levels of 71 percent. Resistance to third-generation cephalosporins was detected in 78 (31.2 percent) of Escherichia coli and 26 (41.9 percent) Klebsiellapneumoniae. From the Escherichia coli and Klebsiellapneumoniae isolates, 143 (57.2 percent) and 35 (56.4 percent),respectively, presented multidrug resistance. Conclusions: There is circulation of strains which are resistant to third generation cephalosporins and multidrug resistants that cause urinary tract infections acquired in the community and there are reports on antibiotics (nitrofurantoin and amikacin) that might be used to combat them empirically in this geographical area(AU)

Clinical analysis of carbapenem-resistant klebsiella pneumoniae-induced neonatal sepsis / 中国新生儿科杂志

Objective To study the clinical feature of carbapenem-resistant klebsiella pneumoniae (CRKP) neonatal sepsis.Method From January 2012 to December 2017,clinical data of newborns with klebsiella pneumoniae (Kp) sepsis admitted to the NICU of our hospital were retrospectively analyzed.Clinical manifestations,laboratory examinations,risk factors,treatments and outcomes were compared between newborns with CRKP sepsis and newborns with carbapenem-sensitive klebsiella pneumoniae (CSKP) sepsis.Result A total of 71 strains of Kp were isolated,representing 33.2％ of all isolated pathogens (71/214).Among 71 newborns diagnosed with Kp sepsis,35 were CRKP sepsis and the other 36 were CSKP sepsis.The incidence of dyspnea/apnea in CRKP group was significantly higher than CSKP group (85.7％ vs.55.6％,P=0.005).Newborns in CRKP group had smaller gestational age than CSKP group.The proportions of male gender,the incidences of continuous positive airway pressure treatment,parenteral nutrition and antibiotics exposure (cephalosporins,penicillins or carbapenems) before the onset of sepsis in CRKP group were higher than CSKP group and the hospital stay before sepsis was longer than CSKP group,the differences were statistically significant (P＜0.05).Logistic regression analysis showed that male gender (OR=8.125,95％CI 2.275～29.021),parenteral nutrition (OR=27.730,95％CI 2.948～260.858) and carbapenems exposure before onset (OR=4.849,95％CI 1.091～21.554) were independent risk factors of neonatal CRKP sepsis (P＜0.05).The mortality rate of CRKP group was higher than the CSKP group (22.9％ vs.5.6％,P=0.036).Conclusion Male,parenteral nutrition and carbapenems exposure before onset were independent risk factors of neonatal CRKP sepsis.CRKP sepsis is critical and has a high mortality rate.Clinicians should monitor drug resistance carefully,follow antibiotics stewardship principles and establish enteral nutrition as soon as possible.

Distribution and antimicrobial resistance profile of Klebsiellapneumoniae / 中国感染与化疗杂志

Objective To investigate the clinical feature and antibiotic resistance profile of K.pneumoniae isolates from patients for better management of K.pneumoniae infections.Methods Nonduplicate K.pneumoniae strains were collected from January to December in 2015.K.pneumoniae strains were identified by VITEK 2-Compact 60 and tested for antimicrobial susceptibility by KirbyBauer method.Results A total of 753 strains ofK.pneumoniae were included,most (40.9％,308/753) of which were isolated from sputum,followed by urine (18.2％,137/753).Most of the strains were from old patients at least 60 years of age (40.8％,307/753),and primarily from intensive care units (16.7％,126/753) and Department of Respiratory Medicine (13.7％,103/753).Respiratory tract infection was found in 144 patients,of which 71.5％ (103/144) were due to K.pneumoniae.More than half of the K.pneumoniae strains were resistant to piperacillin (66.3 ％),cefazolin (60.8 ％) and cefitroxime (59.4 ％).Only a few strain were resistant to imipenem (2.4 ％) and meropenem (2.0).ESBLs were produced in 410 (54.4 ％) of the 753 strains,and 29 (3.9 ％) strains were carbapenem-resistant,492 (65.3 ％) strains were resistant to multiple antimicrobial agents.Conclusions Clinical K.pneumoniae isolates are highly resistant to most of the antimicrobial agents tested.The strains were mostly isolated from sputum and urine,and positive for ESBLs.MDR K.pneumoniae sWains are emerging.K.pneumoniae isolates are still very susceptible to carbapenems in vitro.

Correlation between antimicrobial resistance and antimicrobial use density of Escherichia coli and Klebsiella pneumoniae / 中国感染控制杂志

Objective To investigate antimicrobial resistance of Escherichia coli (E.coli)and Klebsiella pneumoniae (K.pneumoniae),antimicrobial use density(AUD),as well as relation between antimicrobial resistance and AUD in a ter-tiary first-class hospital.Methods Antimicrobial resistance rates of clinically-isolated E.coli and K.pneumoniae,AUD of carbapenems and quinolones,as well as relation between resistance and AUD in 2013-2015 were statistically analyzed. Results Correlation analysis of antimicrobial resistance of bacteria and AUD showed that the decrease in resistance rate of E.coli to levofloxacin was related to the decrease in the use density of quinolones(r=0.61,P=0.03);increase in resist-ance rate of K.pneumoniae to imipenem was related to the increase in the use density of carbapenems(r=0.78,P<0.01). Conclusion Antimicrobial use is one of the causes of bacterial resistance,management on antimicrobial use needs to be strengthened to reduce the threat of bacterial resistance to human health.

Molecular Characterization of Extended Spectrum β-Lactamases, Ampccephalosporinases and Carbapenemases in Klebsiellapneumoniae Causing Bacteremia at Charles Nicolle Hospital of Tunisia.

Purpose of the Study: This study was conducted to detect and characterize the genes encoding extended spectrum β-lactamases and associated β-lactamases (carbapenemases and Ambler Class C β-lactamases). Patients and Methods: In 2011, out of the 65 non-duplicative Klebsiellapneumoniae collected from blood culture at Charles Nicolle hospital of Tunisia, 36 were resistant to 3rd generation cephalosporin. Results: All strains showed a double disk synergy test positive. They were mainly isolated in intensive care unit (31%). They were frequently resistant to most antibiotics tested, except colistin and tigecyclin. Five isolates (13%) showed reduced susceptibility to carbapenems. blaCTX-M-15 was harbored by 35 strains and blaSHV-12 by one. blaCTX-M-15 were associated with blaTEM-1 (n=21), blaOXA-48 and blaCMY-2 (n=1) and blaOXA-48and blaTEM-1 (n=4). The conjugation wassuccessfulfor4/5 strains (3 harboring blaCTX-M-15 and one blaSHV-12). The plasmids carrying the blaCTX-M-15 were assigned to IncN or IncL/M only for 2 strains. The remaining blaCTX-M-15-carrying plasmid was negative for all of the replicons tested as well as the blaSHV-12-carrying plasmid. Conclusion: Our results confirm the spread of CTX-M-15 in our institution. To our knowledge, this is the first report of K. pneumoniae coproducing CTX-M-15, CMY-2 and OXA-48. The implementation of preventive measures against the spread of these multiresistant bacteria is needed.

Application analysis of double-disk synergy test in AmpC β-lactamase detection / 国际检验医学杂志

Objective To investigate and analyze the double-disk inhibiting synergy test for detecting AmpC β-lactamase pro-duced by Klebsiella pneumoniae and to evaluate its application value in clinical laboratory.Methods The cefoxitin disk agar diffu-sion method,cefoxitin three-dimensional method,double-disk inhibiting synergy test and drug resistance gene multiplex PCR assay were adopted to detect the clinically isolated bacterial strains.Results Among 137 clinically isolated strains of Klebsiella pneumoni-ae,22 strains were insensitive to cefoxitin and 11 strains were positive by the three-dimensional method;in the double-disk inhibiting synergy test,18 strains were positive for the FOX/FOX+PBA group and 11 strains were positive for the CTT/CTT+PBA group respectively;in the multiplex PCR assay,19 strains were positive.The coincidence rate of the cefoxitin three-dimensional method and multiplex PCR methods was 47.4%(9/19),in the double-disk inhibiting synergy test,the coincidence rate of the positive re-sults in the CTT/CTT+PBA group and the multiplex PCR methods was 57.9%(11/19);the coincidence rate of the FOX/FOX+PBA group and multiplex PCR methods was 94.7%(18/19).Conclusion The double-disk inhibiting synergy test is simple with highly accurate results,in which the FOX/FOX+PBA double-disk synergy test could be applied to detect AmpC β-lactamase pro-duced by clinical isolates of Klebsiella pneumoniae.

Detección de cepas productoras de b-lactamasas de espectro extendido por el sistema DIRAMIC: Comparación con los métodos doble difusión con discos y E-test / Detection of expanded-espectrum-betalactamases by DIRAMIC system: Comparison with the double-disk synergy test and E-test

The capacity of the DIRAMIC system to detect strains producing extended-spectrum-betalactamase (ESBL) was evaluated through the comparison with two phenotypic confirmatory tests: double-disk synergy test and E-test. Ninety seven clinical isolates of Escherichia coli y Klebsiella spp. previously characterized; not repeated and suspected of being ESBL producers were studied by the three methods. In comparison with E-test and double-disk synergy test, DIRAMIC system showed a sensitivity of 85.7 percent and 92.7 percent as well as specificity of 100 percent and 92.9 percent; respectively. The values found have a very high degree of concordance (kappa index > 0.80). The results obtained vouch for the utility of the DIRAMIC as a rapid method to alert about the presence of strains producing ESBL enzymes.

Se evaluó la capacidad del sistema DIRAMIC-Cuba para detectar cepas productoras de p-lactamasas de espectro extendido (BLEE), mediante la comparación con dos métodos fenotípicos confirmatorios: doble difusión con discos y E-test. Noventa y siete aislados clínicos de Escherichia coli y Klebsieüa spp previamente caracterizados, no repetidos, sospechosos de producir BLEE se estudiaron por los tres procedimientos para determinar sensibilidad, especificidad y concordancia entre los resultados. Para el sistema DIRAMIC se encontró una sensibilidad de 85,7 y 92,7 por ciento y una especificidad de 100 y 92,9 por ciento en comparación con E-test y doble difusión con discos, respectivamente. Los valores de concordancia encontrados fueron muy altos (índice kappa > 0,80). Los resultados obtenidos avalan la utilidad del sistema DIRAMIC como vía rápida, para alertar al médico acerca de la presencia de cepas productoras de BLEE, aunque es necesario profundizar y ampliar el estudio a modo de emitir resultados más precisos.