An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibil...An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.展开更多
Objective:To delineate the frequency of occurrence of bla_(CTX-M),bla_(TEM),and bla_(SHV) in Enterobacteriaceae from North-Indian tertiary hospital.Methods:A random collection of a subset of 45 Escherichia coli(E.coli...Objective:To delineate the frequency of occurrence of bla_(CTX-M),bla_(TEM),and bla_(SHV) in Enterobacteriaceae from North-Indian tertiary hospital.Methods:A random collection of a subset of 45 Escherichia coli(E.coli) and 28 Klebsiella pneumoniae(K.pneumoniae) that was resistant to a third generation cephalosporin and obtained during 2007-2008 was selected for detailed screening for bla_(CTX-M),bla_(TEM),and bla_(SHV) by monoplex PCRs.The isolates demonstrating the presence of bla_(CTX-M) alleles were characterized for the specific CTX-M-genogroup by using a multiplex PCR.Results:Resistance to cefoperazone,ceftazidime,ceftriaxone,cefotaxime, cefoxitin and piperacillin was 100%each in K.pneumoniae isolates,whereas these resistancerates for E.coli isolates were 93.1%,83.8%,91.9%,93.6%,97.3%and 97.1%,respectively. Concomitant resistance to aminoglycosides,quinolones and aztreonam was also noticed.Presence of any of the bla genes(bla_(CTX-M),bla_(TEM),and bla_(SHV)) was noticed in a total of 28(38.4%) isolates of the 73 isolates studied.Many isolates demonstrated occurrence of these genes in various combinations.bla_(CTX-M),bla_(TEM),and bla_(SHV) were noticed in 28.8%,10.9%and 13.7%isolates, respectively.Multiplex PCR in bla_(CTX-M) harboring isolates demonstrated the presence of CTX-MGenogroup -1 and sequencing for the specific CTX-M-type revealed presence of CTX-M-15 type. RAPD typing showed wide diversity in isolates.Conclusions:This is amongst the premier report describing the simultaneous occurrence of blo_(TEM),bla_(SHV),and bla_(ampC) in Indian Enterobacteriaceae and that wider dissemination of these genes,as demonstrated by diversity of isolates,raises concern and emphasizes a need for extensive search for the presence of these gene pools in Indian subcontinent.展开更多
Objective:To look for secondary bacterial infections in bronchogenic carcinoma（BC<sub>A</sub>） with resistant organisms harboring bla genes considering the paucity of relevant studies.Methods: A total of...Objective:To look for secondary bacterial infections in bronchogenic carcinoma（BC<sub>A</sub>） with resistant organisms harboring bla genes considering the paucity of relevant studies.Methods: A total of 137 confirmed cases of BC<sub>A</sub> and 34 healthy volunteers were studied for the occurrence and prevalence of bla<sub>CTX-M</sub> and and bla<sub>AmpC</sub> harboring-enterobacteriaceae.A subset of these patients（n=69） was previously reported for the secondary infection with the Aspergillus species. Bronchoalveolar lavages（BAL） were subjected for bacterial and fungal cultures and the bacterial isolates were screened by multiplex PCRs for the presence of bla<sub>CTX-M</sub> and bla<sub>AmpC</sub>.The isolates were also screened for the association of insertion sequence（IS26） by PCR and characterized by RAPD for any clonal relatedness.Results:A total of 143 bacterial isolates were obtained from 137 BAL specimens of BC,patients.The Enterobacteriaceae-isolates were multidrug-resistant showing concomitant resistance to fluoroquinolones and aminoglycosides.Both bla<sub>CTX-M</sub> and bla<sub>AmpC</sub> of CIT family were detected in 77.4%and 27.4%isolates,respectively.Sequencing revealed the presence of bla<sub>CTX-M-15</sub> and bla<sub>CMY-6</sub>.Twenty one percent of the isolates were simultaneously harboring bla<sub>ampC</sub> and bla<sub>CTX-M-15</sub>.IS26 PCR and RAPD typing revealed the presence of diverse bacterial population but no predominant clone was identified.The present study also suggests strong association of aspergillosis with lung cancer and further strengthens the potential use of non-validated serological tests suggested earlier.Conclusions:We emphasize that all patients of bronchogenic carcinoma should also be screened for secondary bacterial infections,along with secondary fungal infections,so as to introduce early and specific antimicrobial therapy and to prevent unwanted deaths.展开更多
Objective:To determine the molecular epidemiology of extended-spectrumβ-lactamase （ESRL） by testing a cohort of clinical ESBL-producing bacterial isolates that were isolated in the Kingdom of Bahrain.Methods:ESBL p...Objective:To determine the molecular epidemiology of extended-spectrumβ-lactamase （ESRL） by testing a cohort of clinical ESBL-producing bacterial isolates that were isolated in the Kingdom of Bahrain.Methods:ESBL producing Enterabacleriaceae isolates（based on phenotypie tests） were collected from Microbiology Laboratory ot the Salmaniya Medical Complex,Bahrain between January-June 2006.Antibiotic susceptibility to a panel of antibiotics was performed and bla<sub>CTX-M</sub> genes were detected by multiplex PCR.Results:A total of 230 isolates（Escherichia coli.n=180:Klebsiella pneumoniae,n=50） were studied.98%were CTX-M type.For Escherichia coli isolates.65（36.1%） harbored CTXM+TF.M combination and 68（37.8%） had CTX-M alone.In contrast,for Klebsiella pneumoniae isolates only 5（10.0%） harbored the CTX-M combination,and none had CTX-M only.The bla<sub>CTX-M</sub> gene was found predominantly in urine isolates（n=145/230;63.0%）.Sensitivity to imipenem and nitrofurantoin was 100%and 60%.respectively.CTX-M carriage was associated with the resistance lo fluoroquinolones, trimethoprim-sulfamethoxazole and aminoglycosides.Conclusions:Our study documentes high prevalence of CTX-M ESBL type among Escherichia call and Klebsiella from the Kingdom of Bahrain.The apparent dissemination of CTX-M producers could represent a substantial barrier in the treatment of community-acquired infections.The use of extended-Spectrum cephalosporins. quinolones,and aminoglycosides is compromised,leaving carbapenems as the therapeutic option for severe infections caused by ESBL producers.展开更多
Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins ...Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins and other factors involved in various biological processes,includingβ-lactamase and antibiotic-resistance genes.This study aimed to reveal the transmission mechanism of OMV-mediated drug resistance of Klebsiella(K.)pneumoniae.Methods We selected CR-KP producing K.pneumoniae carbapenemase-2(KPC-2)to study whether they can transfer resistance genes through OMVs.The OMVs of CR-KP were obtained by ultracentrifugation,and incubated with carbapenem-sensitive K.pneumoniae for 4 h.Finally,the carbapenem-sensitive K.pneumoniae was tested for the presence of bla_(KPC-2)resistance gene and its sensitivity to carbapenem antibiotics.Results The existence of OMVs was observed by the electron microscopy.The extracted OMVs had bla_(KPC-2)resistance gene.After incubation with OMVs,bla_(KPC-2)resistance gene was detected in sensitive K.pneumoniae,and it became resistant to imipenem and meropenem.Conclusion This study demonstrated that OMVs isolated from KPC-2-producing CR-KP could deliver bla_(KPC-2)to sensitive K.pneumoniae,allowing the bacteria to produce carbapenemase,which may provide a novel target for innovative therapies in combination with conventional antibiotics for treating carbapenem-resistant Enterobacteriaceae.展开更多
Background: Extended-spectrum beta-lactamase (ESBL) producing bacteria are a real public health problem, particularly in Africa. Among these ESBLs, there are the Muenchen Cefotaximase (CTX-M) described all over the wo...Background: Extended-spectrum beta-lactamase (ESBL) producing bacteria are a real public health problem, particularly in Africa. Among these ESBLs, there are the Muenchen Cefotaximase (CTX-M) described all over the world of which the most frequent is the CTX-M of group 1 particularly the CTX-M-15 variant. The objective of this study was to determine the prevalence of CTX-M group 1 ESBL-producing Escherichia coli strains and to test their antibiotics susceptibility profile. Methodology: A retrospective cross-sectional descriptive study was conducted to detect ESBL-secreting Escherichia coli strains by the synergy test. Identification of CTX-M type ESBL from group 1 was performed using the NG-Test CTX-M rapid diagnostic test (NG-Biotech®). Antibiotic susceptibility profile was determined using CA-SFM/EUCAST guidelines 2019. Data entry and statistical analysis were performed with Excel version 2010 and SPSS 20.0 respectively. Results: Eighty-two ESBL-producing Escherichia coli strains were tested. A group 1 CTX-M ESBL was detected in 75.6% of the strains (n = 62). These strains were highly resistant to cefotaxim (100%), aztreonam (100%), ceftazidim (85.4%) and cefepim (66.1%). They were also resistant to quinolones, gentamycin and sulfadoxine-trimethoprim combination. However, these strains showed sensitivity to ertapenem (100%), cefoxitin (69.3%), tigecyclin (66%), and amikacin (66.1%). The combination of piperacillin and tazobactam was active on 30.6% of the strains against 6.4% for the combination of amoxicillin and clavulanic acid. Conclusion: The CTX-M type ESBL of group 1 was present in the majority of ESBL-producing Escherichia colis trains. Despite the production of this enzyme conferring resistance to most beta-lactam antibiotics, some antibiotics remain active to treat infections caused by these germs.展开更多
基金the National Key Research and Development Program of China(2018YFE0192600)the Shanghai Agriculture Applied Technology Development Program,China(T20200104)+1 种基金the Fundamental Research Funds for the Central Universities,China(2020JB05)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ZDRW202203).
文摘An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.
基金Department of Science & Technology,Ministry of Science & Technology,Government of India,for the award of Young Scientist Project(SR/FT/ L-111/2006)
文摘Objective:To delineate the frequency of occurrence of bla_(CTX-M),bla_(TEM),and bla_(SHV) in Enterobacteriaceae from North-Indian tertiary hospital.Methods:A random collection of a subset of 45 Escherichia coli(E.coli) and 28 Klebsiella pneumoniae(K.pneumoniae) that was resistant to a third generation cephalosporin and obtained during 2007-2008 was selected for detailed screening for bla_(CTX-M),bla_(TEM),and bla_(SHV) by monoplex PCRs.The isolates demonstrating the presence of bla_(CTX-M) alleles were characterized for the specific CTX-M-genogroup by using a multiplex PCR.Results:Resistance to cefoperazone,ceftazidime,ceftriaxone,cefotaxime, cefoxitin and piperacillin was 100%each in K.pneumoniae isolates,whereas these resistancerates for E.coli isolates were 93.1%,83.8%,91.9%,93.6%,97.3%and 97.1%,respectively. Concomitant resistance to aminoglycosides,quinolones and aztreonam was also noticed.Presence of any of the bla genes(bla_(CTX-M),bla_(TEM),and bla_(SHV)) was noticed in a total of 28(38.4%) isolates of the 73 isolates studied.Many isolates demonstrated occurrence of these genes in various combinations.bla_(CTX-M),bla_(TEM),and bla_(SHV) were noticed in 28.8%,10.9%and 13.7%isolates, respectively.Multiplex PCR in bla_(CTX-M) harboring isolates demonstrated the presence of CTX-MGenogroup -1 and sequencing for the specific CTX-M-type revealed presence of CTX-M-15 type. RAPD typing showed wide diversity in isolates.Conclusions:This is amongst the premier report describing the simultaneous occurrence of blo_(TEM),bla_(SHV),and bla_(ampC) in Indian Enterobacteriaceae and that wider dissemination of these genes,as demonstrated by diversity of isolates,raises concern and emphasizes a need for extensive search for the presence of these gene pools in Indian subcontinent.
基金Department of Science & Technology,Ministry of Science & Technology,Government of India for awarding "Young Scientist Project Award"(FT/SR-L-111/2006)
文摘Objective:To look for secondary bacterial infections in bronchogenic carcinoma（BC<sub>A</sub>） with resistant organisms harboring bla genes considering the paucity of relevant studies.Methods: A total of 137 confirmed cases of BC<sub>A</sub> and 34 healthy volunteers were studied for the occurrence and prevalence of bla<sub>CTX-M</sub> and and bla<sub>AmpC</sub> harboring-enterobacteriaceae.A subset of these patients（n=69） was previously reported for the secondary infection with the Aspergillus species. Bronchoalveolar lavages（BAL） were subjected for bacterial and fungal cultures and the bacterial isolates were screened by multiplex PCRs for the presence of bla<sub>CTX-M</sub> and bla<sub>AmpC</sub>.The isolates were also screened for the association of insertion sequence（IS26） by PCR and characterized by RAPD for any clonal relatedness.Results:A total of 143 bacterial isolates were obtained from 137 BAL specimens of BC,patients.The Enterobacteriaceae-isolates were multidrug-resistant showing concomitant resistance to fluoroquinolones and aminoglycosides.Both bla<sub>CTX-M</sub> and bla<sub>AmpC</sub> of CIT family were detected in 77.4%and 27.4%isolates,respectively.Sequencing revealed the presence of bla<sub>CTX-M-15</sub> and bla<sub>CMY-6</sub>.Twenty one percent of the isolates were simultaneously harboring bla<sub>ampC</sub> and bla<sub>CTX-M-15</sub>.IS26 PCR and RAPD typing revealed the presence of diverse bacterial population but no predominant clone was identified.The present study also suggests strong association of aspergillosis with lung cancer and further strengthens the potential use of non-validated serological tests suggested earlier.Conclusions:We emphasize that all patients of bronchogenic carcinoma should also be screened for secondary bacterial infections,along with secondary fungal infections,so as to introduce early and specific antimicrobial therapy and to prevent unwanted deaths.
文摘Objective:To determine the molecular epidemiology of extended-spectrumβ-lactamase （ESRL） by testing a cohort of clinical ESBL-producing bacterial isolates that were isolated in the Kingdom of Bahrain.Methods:ESBL producing Enterabacleriaceae isolates（based on phenotypie tests） were collected from Microbiology Laboratory ot the Salmaniya Medical Complex,Bahrain between January-June 2006.Antibiotic susceptibility to a panel of antibiotics was performed and bla<sub>CTX-M</sub> genes were detected by multiplex PCR.Results:A total of 230 isolates（Escherichia coli.n=180:Klebsiella pneumoniae,n=50） were studied.98%were CTX-M type.For Escherichia coli isolates.65（36.1%） harbored CTXM+TF.M combination and 68（37.8%） had CTX-M alone.In contrast,for Klebsiella pneumoniae isolates only 5（10.0%） harbored the CTX-M combination,and none had CTX-M only.The bla<sub>CTX-M</sub> gene was found predominantly in urine isolates（n=145/230;63.0%）.Sensitivity to imipenem and nitrofurantoin was 100%and 60%.respectively.CTX-M carriage was associated with the resistance lo fluoroquinolones, trimethoprim-sulfamethoxazole and aminoglycosides.Conclusions:Our study documentes high prevalence of CTX-M ESBL type among Escherichia call and Klebsiella from the Kingdom of Bahrain.The apparent dissemination of CTX-M producers could represent a substantial barrier in the treatment of community-acquired infections.The use of extended-Spectrum cephalosporins. quinolones,and aminoglycosides is compromised,leaving carbapenems as the therapeutic option for severe infections caused by ESBL producers.
基金supported by the National Natural Science Foundation of China(No.31771189)the Wuhan Health Commission(No.WX18C17 and No.WX19Q31)the Natural Science Foundation of Hubei Province,China(No.2017CFA065 and No.WJ2019H378).
文摘Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins and other factors involved in various biological processes,includingβ-lactamase and antibiotic-resistance genes.This study aimed to reveal the transmission mechanism of OMV-mediated drug resistance of Klebsiella(K.)pneumoniae.Methods We selected CR-KP producing K.pneumoniae carbapenemase-2(KPC-2)to study whether they can transfer resistance genes through OMVs.The OMVs of CR-KP were obtained by ultracentrifugation,and incubated with carbapenem-sensitive K.pneumoniae for 4 h.Finally,the carbapenem-sensitive K.pneumoniae was tested for the presence of bla_(KPC-2)resistance gene and its sensitivity to carbapenem antibiotics.Results The existence of OMVs was observed by the electron microscopy.The extracted OMVs had bla_(KPC-2)resistance gene.After incubation with OMVs,bla_(KPC-2)resistance gene was detected in sensitive K.pneumoniae,and it became resistant to imipenem and meropenem.Conclusion This study demonstrated that OMVs isolated from KPC-2-producing CR-KP could deliver bla_(KPC-2)to sensitive K.pneumoniae,allowing the bacteria to produce carbapenemase,which may provide a novel target for innovative therapies in combination with conventional antibiotics for treating carbapenem-resistant Enterobacteriaceae.
文摘Background: Extended-spectrum beta-lactamase (ESBL) producing bacteria are a real public health problem, particularly in Africa. Among these ESBLs, there are the Muenchen Cefotaximase (CTX-M) described all over the world of which the most frequent is the CTX-M of group 1 particularly the CTX-M-15 variant. The objective of this study was to determine the prevalence of CTX-M group 1 ESBL-producing Escherichia coli strains and to test their antibiotics susceptibility profile. Methodology: A retrospective cross-sectional descriptive study was conducted to detect ESBL-secreting Escherichia coli strains by the synergy test. Identification of CTX-M type ESBL from group 1 was performed using the NG-Test CTX-M rapid diagnostic test (NG-Biotech®). Antibiotic susceptibility profile was determined using CA-SFM/EUCAST guidelines 2019. Data entry and statistical analysis were performed with Excel version 2010 and SPSS 20.0 respectively. Results: Eighty-two ESBL-producing Escherichia coli strains were tested. A group 1 CTX-M ESBL was detected in 75.6% of the strains (n = 62). These strains were highly resistant to cefotaxim (100%), aztreonam (100%), ceftazidim (85.4%) and cefepim (66.1%). They were also resistant to quinolones, gentamycin and sulfadoxine-trimethoprim combination. However, these strains showed sensitivity to ertapenem (100%), cefoxitin (69.3%), tigecyclin (66%), and amikacin (66.1%). The combination of piperacillin and tazobactam was active on 30.6% of the strains against 6.4% for the combination of amoxicillin and clavulanic acid. Conclusion: The CTX-M type ESBL of group 1 was present in the majority of ESBL-producing Escherichia colis trains. Despite the production of this enzyme conferring resistance to most beta-lactam antibiotics, some antibiotics remain active to treat infections caused by these germs.
