The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only ...The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to establish the carriage of multi-drug resistance and extended-spectrum beta-lactamase genes in Escherichia coli from farmers, their cattle, and cattle slurry within Kiambu County. A total of 286 (81%) E. coli isolates were recovered from 352 samples analysed. Antibiotic resistance profiles showed 114 (40%) isolates were resistant to ≥3 antimicrobial classes and were considered multidrug-resistant. Among multidrug-resistant (MDR) E. coli strains, 40 (14%) were resistant to 3 different antimicrobial classes, while 71 (25%) were resistant to between 4 and 7 antibiotic classes. Extended-spectrum β-lactamase resistance was found in 18 isolates: human (n = 14), cattle (n = 2), and environmental (n = 2). Both the bla<sub>CTX-M</sub> and bla<sub>TEM</sub> genes were detected in 10 and 15 strains, respectively. Sequence analysis showed that the isolates carried the bla<sub>TEM-116</sub> (n = 7), bla<sub>TEM-1</sub> (n = 5), and bla<sub>CTX-M-15</sub> (n = 8) genes. Genotyping MDR isolates using (GTG) <sub>5</sub> PCR demonstrated that the isolates were not clonal. This data shows antimicrobial resistance profiles and different types of resistance genes in the E. coli population on dairy farms. As a result, more effective, targeted public health policies and measures need to be put in place to control and prevent the emergence and spread of resistant bacteria.展开更多
The purpose of this paper was to create a compendium of serogroups, serotypes and untypeable strains of Shigatoxigenic/verotoxigenic (STEC/VTEC) Escherichia coli. The compendium includes the origins, bacteriological a...The purpose of this paper was to create a compendium of serogroups, serotypes and untypeable strains of Shigatoxigenic/verotoxigenic (STEC/VTEC) Escherichia coli. The compendium includes the origins, bacteriological and clinical data on this important group of microbes. The collection of STEC/VTEC data extends from 1980 to 2017, and excludes STEC/VTEC O157:H7. A total of 499 papers were discovered and documented to create the compendium which includes all the serogroups and serotypes beginning with serogroup O1 through to serogroup O211 and includes O non-typeable strains and ill-defined strains including serotype O"54071":H7. The paper summarises the findings of 8010 E. coli isolates and includes all details including source (human or animal), and clinical condition/disease, serogroup and serotypes, country of origin, year reported, and the author(s) with cited references. Some twenty clinical conditions were shown in association with 4320 serotypes/and untypeable strains. The compendium is a record of an important group of STEC/ VTEC and should provide a useful resource for both researchers and clinicians.展开更多
Midkine is a heparin-binding growth factor, which plays important roles in the regulation of cell growth and differentiation. The non-tagged recombinant human midkine （rhMK） is therefore required to facilitate its f...Midkine is a heparin-binding growth factor, which plays important roles in the regulation of cell growth and differentiation. The non-tagged recombinant human midkine （rhMK） is therefore required to facilitate its functional studies of this important growth factor. In the present work, rhMK was expressed in Escherichia coli （E. coli） BL21 （DE3）. The expression of midkine was efficiently induced by isopropyl-13-D-thiogalactopyranoside （IPTG）. After sonication, midkine was recovered in an insoluble form, and was dissolved in guanidine hydrochloride buffer. Renaturation of the denatured protein was carried out in the defined protein refolding buffer, and the refolded protein was purified using S-Sepharose ion-exchange chromatography. The final preparation of the rhMK was greater than 98% pure as measured by sodium dodecylsulfate-polyacrylamid gel electrophoresis （SDS-PAGE） and reverse phase high performance liquid chromatography （RP-HPLC）. The purified rhMK enhanced the proliferation of NIH3T3 cells.展开更多
文摘The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to establish the carriage of multi-drug resistance and extended-spectrum beta-lactamase genes in Escherichia coli from farmers, their cattle, and cattle slurry within Kiambu County. A total of 286 (81%) E. coli isolates were recovered from 352 samples analysed. Antibiotic resistance profiles showed 114 (40%) isolates were resistant to ≥3 antimicrobial classes and were considered multidrug-resistant. Among multidrug-resistant (MDR) E. coli strains, 40 (14%) were resistant to 3 different antimicrobial classes, while 71 (25%) were resistant to between 4 and 7 antibiotic classes. Extended-spectrum β-lactamase resistance was found in 18 isolates: human (n = 14), cattle (n = 2), and environmental (n = 2). Both the bla<sub>CTX-M</sub> and bla<sub>TEM</sub> genes were detected in 10 and 15 strains, respectively. Sequence analysis showed that the isolates carried the bla<sub>TEM-116</sub> (n = 7), bla<sub>TEM-1</sub> (n = 5), and bla<sub>CTX-M-15</sub> (n = 8) genes. Genotyping MDR isolates using (GTG) <sub>5</sub> PCR demonstrated that the isolates were not clonal. This data shows antimicrobial resistance profiles and different types of resistance genes in the E. coli population on dairy farms. As a result, more effective, targeted public health policies and measures need to be put in place to control and prevent the emergence and spread of resistant bacteria.
文摘The purpose of this paper was to create a compendium of serogroups, serotypes and untypeable strains of Shigatoxigenic/verotoxigenic (STEC/VTEC) Escherichia coli. The compendium includes the origins, bacteriological and clinical data on this important group of microbes. The collection of STEC/VTEC data extends from 1980 to 2017, and excludes STEC/VTEC O157:H7. A total of 499 papers were discovered and documented to create the compendium which includes all the serogroups and serotypes beginning with serogroup O1 through to serogroup O211 and includes O non-typeable strains and ill-defined strains including serotype O"54071":H7. The paper summarises the findings of 8010 E. coli isolates and includes all details including source (human or animal), and clinical condition/disease, serogroup and serotypes, country of origin, year reported, and the author(s) with cited references. Some twenty clinical conditions were shown in association with 4320 serotypes/and untypeable strains. The compendium is a record of an important group of STEC/ VTEC and should provide a useful resource for both researchers and clinicians.
基金Project supported in part by the Hi-Tech Research and Development Program(863) of China(No.2007AA02Z149)the Science and Technology Commissionof Shanghai Municipality(No.075407071),China
文摘Midkine is a heparin-binding growth factor, which plays important roles in the regulation of cell growth and differentiation. The non-tagged recombinant human midkine （rhMK） is therefore required to facilitate its functional studies of this important growth factor. In the present work, rhMK was expressed in Escherichia coli （E. coli） BL21 （DE3）. The expression of midkine was efficiently induced by isopropyl-13-D-thiogalactopyranoside （IPTG）. After sonication, midkine was recovered in an insoluble form, and was dissolved in guanidine hydrochloride buffer. Renaturation of the denatured protein was carried out in the defined protein refolding buffer, and the refolded protein was purified using S-Sepharose ion-exchange chromatography. The final preparation of the rhMK was greater than 98% pure as measured by sodium dodecylsulfate-polyacrylamid gel electrophoresis （SDS-PAGE） and reverse phase high performance liquid chromatography （RP-HPLC）. The purified rhMK enhanced the proliferation of NIH3T3 cells.
