Objective To study the protective effects of naja naja atra venom （NNAV） in a rat model of diabetic nephropathy （DN）. Methods The rat diabetes model was induced by intraperitoneal injection of streptozotocin （STZ...Objective To study the protective effects of naja naja atra venom （NNAV） in a rat model of diabetic nephropathy （DN）. Methods The rat diabetes model was induced by intraperitoneal injection of streptozotocin （STZ）. Thirty-two model rats were randomly divided into one DN group （n=8） and three treatment groups （n=8 each） that received NNAV at doses of 30, 90, or 270 I^g/（ks.day） via oral gavage, another eight rats as normal controls. After 12 weeks, all rats were sacrificed and the changes in serum and urine biological index levels were determined by colorimetric assay. Microalbumin （mALB）, N-acetyl-13- glucosaminidase （NAG） and cystatin C （CysC） concentrations were measured by ELISA. Renal tissues were sliced for pathological and immunohistochemical observations. Results Comparied with the DN group, serum glucose was decreased by 31.04%, total cholesterol 21.96%, triglyceride 23.78%, serum creatinine 19.83%, blood urea nitrogen 31.28%, urinary protein excretion 45.42%, mALB 10.42%, NAG 20.65%, CysC 19.57%, whereas albumin increased by 5.55%, high-density lipoprotein-cholesterol 59.09%, creatinine clearance 19.05% in the treatment group by NNAV administration at dose of 90 μg/（kg-day）. NNAV also reduced the levels of malondialdehyde in serum （22.56%） and kidney tissue （9.79%）, and increased superoxide dismutase concentration in serum （15%） and decreased it in renal tissue （8.85%）. In addition, under light microscopy kidney structure was improved and glomerular hypertrophy decreased by 8.29%. As shown by immunohistochemistry, NNAV inhibited transforming growth factorl by 6.70% and nuclear actor-KB by 5.15%.展开更多
In this study we explored electrophoretic profiles, enzymatic activities and immunoreactivity of neonate and adult venoms from two snakes （Naja atra and Deinagkistrodon acutus） coexisting in southeastern China. Age-...In this study we explored electrophoretic profiles, enzymatic activities and immunoreactivity of neonate and adult venoms from two snakes （Naja atra and Deinagkistrodon acutus） coexisting in southeastern China. Age-related variation in electrophoretic profiles was found in both species and proteolytic and fibrinogenolytic activity was higher in neonate than adult venoms. Neonate D. acutus venom had higher 5＇ nucleotidase, PLA2, hyaluronidase and gelatinolytie activity, but lower esterolytic activity, than adult venom. Neonate and adult D. acutus venoms showed identical phosphomonoesterase, LAO and fibrinolytic activities. Neonate N. atra venom had higher phosphomonoesterase and LAO activity, but lower 5＇ nucleotidase, PLA2, hyaluronidase and Ache activities than adult venom. Neonate and adult N. atra venoms showed similar gelatinolytic activity. Further, age-dependent immunoreactivity was found in both species, and cross-reactions between homologous venoms and antiserums were closely related to venom composition. We speculate that age-related variation in venom characteristics is possibly driven by evolutionary forces associated with ontogenetic shifts in dietary habits, competition and predation pressure.展开更多
Detailed information on venom yield is helpful in preparing antivenoms and treating snakebites, but such information is lacking for many species of venomous snakes. The Chinese cobra(Naja atra) is a large sized, venom...Detailed information on venom yield is helpful in preparing antivenoms and treating snakebites, but such information is lacking for many species of venomous snakes. The Chinese cobra(Naja atra) is a large sized, venomous snake commonly found in southeastern China, where it causes a heavy burden of snakebites. To examine the effects of various factors(morphology, sex, age, season, and geographical origin) on the venom yield in this snake, we collected venom samples of 446 individuals(426 adults and 20 neonates) from 10 populations of N. atra over an eightyear period. We used two variables, lyophilized venom mass(venom yield) and solid content of venom(% solids), to quantify the venom yield. We used linear regression analysis to check if venom yield was related to morphological factors, one-way ANOVA and one-way ANCOVA to detect the sexual, ontogenetic, and geographic variation in venom yield, and repeated-measures ANOVA to examine seasonal shifts in venom yield. Our results indicate that venom yield of N. atra is positively related to the morphological traits examined, with male snakes expelling more venom than females. Venom yield in N. atra was age-related, with elder snakes always expelling more venom than younger ones. Geographic variation in venom yield was also observed, while seasonal variation was not. The solid content of venom was lower in males than in females, but this was not related to morphology, season, age, or geography. Our findings suggest that venom yield in N. atra is influenced by multiple factors, as well as by the interactions among these factors.展开更多
Changes in structure and composition of the eggshell resulting from embryonic mobilization of minerals from the eggshell are found in all oviparous reptiles studied thus far. In this study, we measured samples of unha...Changes in structure and composition of the eggshell resulting from embryonic mobilization of minerals from the eggshell are found in all oviparous reptiles studied thus far. In this study, we measured samples of unhatched and hatched eggshells of the Chinese cobra Naja atra to determine the percentage of ash and the phase composition of calcium carbonate. The mean percentage of ash was significantly higher in unhatched eggshells （24.6%） than in hatched eggshells （22.3%）. The dominant phase in unhatched eggshells was the calcite form of calcium carbonate. In addition to the peaks of calcite, a few small peaks were found to be caused by the aragonite and vaterite phases of calcium carbonate, implying that there are small amounts of aragonite and vaterite in the eggshell. The concentration of the various phases calculated from the intensity of the X-ray diffraction spectra allowed the estimation that percentages of calcite, aragonite and vaterite were about 92%, 4% and 4%, respectively. Hatched eggshells produced similar spectral characteristics as unhatched eggshells, with one exception. The dominant phase composition in the hatched eggshell was also calcite, but the amount of the aragonite phase had a marked increase. Our study adds evidence that embryonic mobilization of minerals from the eggshell may result in changes in structure of the eggshell.展开更多
Over recent years, the population of Caspian cobra Naja oxiana has declined in its distribution range in Iran due to habitat destruction and overhunting. Consequently, their small and isolated populations in fragmente...Over recent years, the population of Caspian cobra Naja oxiana has declined in its distribution range in Iran due to habitat destruction and overhunting. Consequently, their small and isolated populations in fragmented landscapes are facing genetic and demographic threats. Evaluating the spatial distribution pattern of Naja oxiana, identifying core habitat patches and improving landscape connectivity among the patches have a significant role in the long-term survival of the species. This study predicts the spatial distribution map of the Caspian cobra considering the factors affecting the predictive power of the distribution models, including sampling bias in presence points, correct selection of background locations, and input model parameters. The sampling bias in presence points was removed using spatial filtering. Several models were run using 19 environmental variables that eventually led to the selection of the effective habitat variables and best MaxEnt distribution model. We also used an ensemble model(EM) of habitat suitability methods to predict the potential habitats of the species. Topographical roughness, shrublands, average annual precipitation, and sparse rangeland with a density of ≤ 20% had the most effect on the spatial distribution of Caspian cobra. The evaluation of models confirmed that the EM has more predictive performance than MaxEnt in predicting the distribution of Naja oxiana.展开更多
Objective:To explore the cytotoxicity effects of Caspian cobra(Naja oxiana or N.oxiana) venom on hepatocytes and mitochondria obtained from the liver of HCC rats.Methods:In this study,HCC was induced by diethylnitrosa...Objective:To explore the cytotoxicity effects of Caspian cobra(Naja oxiana or N.oxiana) venom on hepatocytes and mitochondria obtained from the liver of HCC rats.Methods:In this study,HCC was induced by diethylnitrosamine(DEN),as an initiator,and 2-acetylaminofluorene(2-AAF),as a promoter.Rat liver hepatocytes and mitochondria for evaluation of the selective cytotoxic effect of N.oxiana venom were isolated and mitochondria and cellular parameters related to apoptosis signaling were then determined.Results:Our results showed a raise in mitochondrial reactive oxygen species(ROS)level,swelling in mitochondria,mitochondrial membrane potential(Djm) collapse and release of cytochrome c after exposure of mitochondria only isolated from the HCC group with the crude venom of the N.oxiana(12.5,25,and 50 mg/m L).This crude venom also induced caspase-3 activation(P < 0.001) in the hepatocytes obtained only from the HCC rat liver.Conclusions:Based on the over all results,we suggested that N.oxiana may be considered as a promising complementary therapeutic agent for the treatment of HCC.展开更多
Objective:To evaluate the neutralizing effects of flavonoids on snake venom toxicity by stand-alone and combinatorial approaches.Methods:Synthetic flavonoids were assessed,either individually or in combination with an...Objective:To evaluate the neutralizing effects of flavonoids on snake venom toxicity by stand-alone and combinatorial approaches.Methods:Synthetic flavonoids were assessed,either individually or in combination with antivenom,for their neutralization of phospholipase A_(2)(PLA_(2)),protease,antioxidant(DPPH)assay and hemotoxic activity.Molecular docking studies were performed to understand possible binding of flavonoids with Naja naja venom PLA_(2).In vivo studies were carried out to confirm the neutralisation effects using a mouse model.Moreover,inhibition of PLA_(2) was monitored using combinatorial approaches.Results:Among the flavonoids used,quercetin and naringenin inhibited PLA_(2)(56%and 45%),protease(71%and 64%),DPPH scavenging(69.0%and 77.5%)and hemotoxic(70%)activities.Molecular docking studies indicated that the flavonoids bind to the substrate-binding site of PLA_(2)(Cys44 and Tyr63).In vivo studies showed a reduction in the venom toxicity level in the presence of naringenin.Additionally,combinatorial studies using the mixture of flavonoid and anti-venom revealed the possibility of synergistic effect(up to 32%enhancement)in neutralising the venom enzymes.Conclusions:These flavonoids can be used as additives for the treatment of snake bites,which may exert synergistic effects in combination with antivenom and decrease the post-therapeutic effects caused by excessive use of antivenom.展开更多
Theroleof nicheevolution(niche conservatism or niche divergence)in lineage diversification is a poorly studied area.The Chinese cobra Naja atra(Elapidae)has diverged into three lineages:Lineage E in eastern China,Line...Theroleof nicheevolution(niche conservatism or niche divergence)in lineage diversification is a poorly studied area.The Chinese cobra Naja atra(Elapidae)has diverged into three lineages:Lineage E in eastern China,Lineage S in southern China and Vietnam,and Lineage W in western China.However,whether the ecological niche is conserved or divergent among these three lineages is unknown.In the present study,we used ecological niche models in geographical space to study the ecological differences among lineages.We compared the niche overlap in environmental space to test niche conservatism and niche divergence.Our results showed that the three lineages of N.atra shared an ecological niche space between Lineages E and S/W,with the climatic niches of Lineages S and W representing a specialized fraction of the climatic niche of Lineage E.We speculated that the niche divergence between Lineages S and W was a consequence of geographical barriers limitinggeneflow.Ourstudyprovides evidence for lineage diversification associated with both geographical isolation and climatic niche evolution,suggesting that early niche divergence between Lineages S and W,followed by niche conservatism,causes niche divergence among lineages.展开更多
The emergence and spread of antibiotic resistance genes among Bacteria are a serious threat to global health.Their occurrence in animals which are in contact with humans is also important.The Chinese cobra(Naja atra,E...The emergence and spread of antibiotic resistance genes among Bacteria are a serious threat to global health.Their occurrence in animals which are in contact with humans is also important.The Chinese cobra(Naja atra,Elapidae),though a highly venomous species,is appreciated as food and as a source of materials used in traditional Chinese medicine.We are here reporting the isolation of multidrug-resistant Klebsiella pneumoniae(Enterobacteriaceae)from the lung of Naja atra,obtained from a snake farm in a Beijing suburb.Our study analyzed,using gene sequencing,the occurrence of antibiotic resistance genes(ARGs)in three K.pneumoniae isolates from two snakes.In addition,bacterial clones were identified by biochemical tests and phylogenetic analysis.Tests of antimicrobial susceptibility showed that all K.pneumoniae isolates were resistant to a host of antibiotics(piperacillin,cefazolin,gentamicin,tetracycline,doxycyclin,ciprofloxacin,levofloxacin,lomefloxacin,ofloxacin,norfloxacin,nalidixic acid,chloramphenicol,nitrofurantoin,sulfamethoxazole,and sulfamethoxazole/trimethoprim)but were susceptible to cefotaxime,cefixime,aztreonam,bramycin,amikacin,kanamycin,netilmicin,and streptomycin.Eighteen ARGs were detected in total DNA extracted from the isolates.Results showed three quinolone resistance genes(oqxA,oqxB,qnrB),the gyrA gene that confers resistance to beta-lactam antibiotics,and the emerging aac(3)-II gene that confers resistance to aminoglycosides.K.pneumoniae is an important opportunistic human pathogen and the emergence of multidrug-resistant K.pneumoniae in N.atra suggests the increasing risk of pathogen transmission between humans,livestock,and wildlife.Given the close association between foodborne pathogenic microorganisms and humans,it is key factor to identify these antibiotic resistance genes profile thereby minimize the risk of K.pneumoniae transmission.展开更多
基金supported by the Research Project of the Jiangsu Province Key Provincial Talents Program,RC2011112
文摘Objective To study the protective effects of naja naja atra venom （NNAV） in a rat model of diabetic nephropathy （DN）. Methods The rat diabetes model was induced by intraperitoneal injection of streptozotocin （STZ）. Thirty-two model rats were randomly divided into one DN group （n=8） and three treatment groups （n=8 each） that received NNAV at doses of 30, 90, or 270 I^g/（ks.day） via oral gavage, another eight rats as normal controls. After 12 weeks, all rats were sacrificed and the changes in serum and urine biological index levels were determined by colorimetric assay. Microalbumin （mALB）, N-acetyl-13- glucosaminidase （NAG） and cystatin C （CysC） concentrations were measured by ELISA. Renal tissues were sliced for pathological and immunohistochemical observations. Results Comparied with the DN group, serum glucose was decreased by 31.04%, total cholesterol 21.96%, triglyceride 23.78%, serum creatinine 19.83%, blood urea nitrogen 31.28%, urinary protein excretion 45.42%, mALB 10.42%, NAG 20.65%, CysC 19.57%, whereas albumin increased by 5.55%, high-density lipoprotein-cholesterol 59.09%, creatinine clearance 19.05% in the treatment group by NNAV administration at dose of 90 μg/（kg-day）. NNAV also reduced the levels of malondialdehyde in serum （22.56%） and kidney tissue （9.79%）, and increased superoxide dismutase concentration in serum （15%） and decreased it in renal tissue （8.85%）. In addition, under light microscopy kidney structure was improved and glomerular hypertrophy decreased by 8.29%. As shown by immunohistochemistry, NNAV inhibited transforming growth factorl by 6.70% and nuclear actor-KB by 5.15%.
基金supported by grants from the Natural Science Foundation of China (31101635 and 31272294)Zhejiang Provincial Foundation of Natural Science (Z3090461)+1 种基金Zhejiang Provincial Department of Science and Technology (2009C13045) Hangzhou Department of Science and Technology (20080433T03)
文摘In this study we explored electrophoretic profiles, enzymatic activities and immunoreactivity of neonate and adult venoms from two snakes （Naja atra and Deinagkistrodon acutus） coexisting in southeastern China. Age-related variation in electrophoretic profiles was found in both species and proteolytic and fibrinogenolytic activity was higher in neonate than adult venoms. Neonate D. acutus venom had higher 5＇ nucleotidase, PLA2, hyaluronidase and gelatinolytie activity, but lower esterolytic activity, than adult venom. Neonate and adult D. acutus venoms showed identical phosphomonoesterase, LAO and fibrinolytic activities. Neonate N. atra venom had higher phosphomonoesterase and LAO activity, but lower 5＇ nucleotidase, PLA2, hyaluronidase and Ache activities than adult venom. Neonate and adult N. atra venoms showed similar gelatinolytic activity. Further, age-dependent immunoreactivity was found in both species, and cross-reactions between homologous venoms and antiserums were closely related to venom composition. We speculate that age-related variation in venom characteristics is possibly driven by evolutionary forces associated with ontogenetic shifts in dietary habits, competition and predation pressure.
基金supported by grants from the National Natural Science Foundation of China (31101635, 31471995 and 31770428)Zhejiang Provincial Foundation of Science (LY14C030007)Open Fund of Jiangsu Key Laboratory for Biodiversity and Biotechnology
文摘Detailed information on venom yield is helpful in preparing antivenoms and treating snakebites, but such information is lacking for many species of venomous snakes. The Chinese cobra(Naja atra) is a large sized, venomous snake commonly found in southeastern China, where it causes a heavy burden of snakebites. To examine the effects of various factors(morphology, sex, age, season, and geographical origin) on the venom yield in this snake, we collected venom samples of 446 individuals(426 adults and 20 neonates) from 10 populations of N. atra over an eightyear period. We used two variables, lyophilized venom mass(venom yield) and solid content of venom(% solids), to quantify the venom yield. We used linear regression analysis to check if venom yield was related to morphological factors, one-way ANOVA and one-way ANCOVA to detect the sexual, ontogenetic, and geographic variation in venom yield, and repeated-measures ANOVA to examine seasonal shifts in venom yield. Our results indicate that venom yield of N. atra is positively related to the morphological traits examined, with male snakes expelling more venom than females. Venom yield in N. atra was age-related, with elder snakes always expelling more venom than younger ones. Geographic variation in venom yield was also observed, while seasonal variation was not. The solid content of venom was lower in males than in females, but this was not related to morphology, season, age, or geography. Our findings suggest that venom yield in N. atra is influenced by multiple factors, as well as by the interactions among these factors.
基金supported by grants from the National Natural Science Foundation of China (30370229 and 31272294)Priority Academic Program Development of Jiangsu Higher Education Institutions and High Academic Talent Foundation of Nanjing Forestry University (GXL201306)
文摘Changes in structure and composition of the eggshell resulting from embryonic mobilization of minerals from the eggshell are found in all oviparous reptiles studied thus far. In this study, we measured samples of unhatched and hatched eggshells of the Chinese cobra Naja atra to determine the percentage of ash and the phase composition of calcium carbonate. The mean percentage of ash was significantly higher in unhatched eggshells （24.6%） than in hatched eggshells （22.3%）. The dominant phase in unhatched eggshells was the calcite form of calcium carbonate. In addition to the peaks of calcite, a few small peaks were found to be caused by the aragonite and vaterite phases of calcium carbonate, implying that there are small amounts of aragonite and vaterite in the eggshell. The concentration of the various phases calculated from the intensity of the X-ray diffraction spectra allowed the estimation that percentages of calcite, aragonite and vaterite were about 92%, 4% and 4%, respectively. Hatched eggshells produced similar spectral characteristics as unhatched eggshells, with one exception. The dominant phase composition in the hatched eggshell was also calcite, but the amount of the aragonite phase had a marked increase. Our study adds evidence that embryonic mobilization of minerals from the eggshell may result in changes in structure of the eggshell.
文摘Over recent years, the population of Caspian cobra Naja oxiana has declined in its distribution range in Iran due to habitat destruction and overhunting. Consequently, their small and isolated populations in fragmented landscapes are facing genetic and demographic threats. Evaluating the spatial distribution pattern of Naja oxiana, identifying core habitat patches and improving landscape connectivity among the patches have a significant role in the long-term survival of the species. This study predicts the spatial distribution map of the Caspian cobra considering the factors affecting the predictive power of the distribution models, including sampling bias in presence points, correct selection of background locations, and input model parameters. The sampling bias in presence points was removed using spatial filtering. Several models were run using 19 environmental variables that eventually led to the selection of the effective habitat variables and best MaxEnt distribution model. We also used an ensemble model(EM) of habitat suitability methods to predict the potential habitats of the species. Topographical roughness, shrublands, average annual precipitation, and sparse rangeland with a density of ≤ 20% had the most effect on the spatial distribution of Caspian cobra. The evaluation of models confirmed that the EM has more predictive performance than MaxEnt in predicting the distribution of Naja oxiana.
基金supported by Shahid Beheshti University of Medical Sciences,Deputy of Research(Grant No.1394-1-95-11835,2015)
文摘Objective:To explore the cytotoxicity effects of Caspian cobra(Naja oxiana or N.oxiana) venom on hepatocytes and mitochondria obtained from the liver of HCC rats.Methods:In this study,HCC was induced by diethylnitrosamine(DEN),as an initiator,and 2-acetylaminofluorene(2-AAF),as a promoter.Rat liver hepatocytes and mitochondria for evaluation of the selective cytotoxic effect of N.oxiana venom were isolated and mitochondria and cellular parameters related to apoptosis signaling were then determined.Results:Our results showed a raise in mitochondrial reactive oxygen species(ROS)level,swelling in mitochondria,mitochondrial membrane potential(Djm) collapse and release of cytochrome c after exposure of mitochondria only isolated from the HCC group with the crude venom of the N.oxiana(12.5,25,and 50 mg/m L).This crude venom also induced caspase-3 activation(P < 0.001) in the hepatocytes obtained only from the HCC rat liver.Conclusions:Based on the over all results,we suggested that N.oxiana may be considered as a promising complementary therapeutic agent for the treatment of HCC.
文摘Objective:To evaluate the neutralizing effects of flavonoids on snake venom toxicity by stand-alone and combinatorial approaches.Methods:Synthetic flavonoids were assessed,either individually or in combination with antivenom,for their neutralization of phospholipase A_(2)(PLA_(2)),protease,antioxidant(DPPH)assay and hemotoxic activity.Molecular docking studies were performed to understand possible binding of flavonoids with Naja naja venom PLA_(2).In vivo studies were carried out to confirm the neutralisation effects using a mouse model.Moreover,inhibition of PLA_(2) was monitored using combinatorial approaches.Results:Among the flavonoids used,quercetin and naringenin inhibited PLA_(2)(56%and 45%),protease(71%and 64%),DPPH scavenging(69.0%and 77.5%)and hemotoxic(70%)activities.Molecular docking studies indicated that the flavonoids bind to the substrate-binding site of PLA_(2)(Cys44 and Tyr63).In vivo studies showed a reduction in the venom toxicity level in the presence of naringenin.Additionally,combinatorial studies using the mixture of flavonoid and anti-venom revealed the possibility of synergistic effect(up to 32%enhancement)in neutralising the venom enzymes.Conclusions:These flavonoids can be used as additives for the treatment of snake bites,which may exert synergistic effects in combination with antivenom and decrease the post-therapeutic effects caused by excessive use of antivenom.
基金supported by grants from the National Natural Science Foundation of China (32071493, 31971414 and 31770443)Finance Science and Technology Project of Hainan Province (ZDYF2018219)
文摘Theroleof nicheevolution(niche conservatism or niche divergence)in lineage diversification is a poorly studied area.The Chinese cobra Naja atra(Elapidae)has diverged into three lineages:Lineage E in eastern China,Lineage S in southern China and Vietnam,and Lineage W in western China.However,whether the ecological niche is conserved or divergent among these three lineages is unknown.In the present study,we used ecological niche models in geographical space to study the ecological differences among lineages.We compared the niche overlap in environmental space to test niche conservatism and niche divergence.Our results showed that the three lineages of N.atra shared an ecological niche space between Lineages E and S/W,with the climatic niches of Lineages S and W representing a specialized fraction of the climatic niche of Lineage E.We speculated that the niche divergence between Lineages S and W was a consequence of geographical barriers limitinggeneflow.Ourstudyprovides evidence for lineage diversification associated with both geographical isolation and climatic niche evolution,suggesting that early niche divergence between Lineages S and W,followed by niche conservatism,causes niche divergence among lineages.
基金We thank the Key Scientific Research Projects of Higher Education Institutions in Henan Province under grant number 19A180021the Research Projects of Employment and Entrepreneurship of Secondary and Higher Education Institutions in Henan Province under grant number JYB2018534+1 种基金the Campus Scientific&Research Fund Project of Yellow River Conservancy Technical Institute under grant number 2017QNKY012National Natural Sciences Foundation of China under grant number 31101806.
文摘The emergence and spread of antibiotic resistance genes among Bacteria are a serious threat to global health.Their occurrence in animals which are in contact with humans is also important.The Chinese cobra(Naja atra,Elapidae),though a highly venomous species,is appreciated as food and as a source of materials used in traditional Chinese medicine.We are here reporting the isolation of multidrug-resistant Klebsiella pneumoniae(Enterobacteriaceae)from the lung of Naja atra,obtained from a snake farm in a Beijing suburb.Our study analyzed,using gene sequencing,the occurrence of antibiotic resistance genes(ARGs)in three K.pneumoniae isolates from two snakes.In addition,bacterial clones were identified by biochemical tests and phylogenetic analysis.Tests of antimicrobial susceptibility showed that all K.pneumoniae isolates were resistant to a host of antibiotics(piperacillin,cefazolin,gentamicin,tetracycline,doxycyclin,ciprofloxacin,levofloxacin,lomefloxacin,ofloxacin,norfloxacin,nalidixic acid,chloramphenicol,nitrofurantoin,sulfamethoxazole,and sulfamethoxazole/trimethoprim)but were susceptible to cefotaxime,cefixime,aztreonam,bramycin,amikacin,kanamycin,netilmicin,and streptomycin.Eighteen ARGs were detected in total DNA extracted from the isolates.Results showed three quinolone resistance genes(oqxA,oqxB,qnrB),the gyrA gene that confers resistance to beta-lactam antibiotics,and the emerging aac(3)-II gene that confers resistance to aminoglycosides.K.pneumoniae is an important opportunistic human pathogen and the emergence of multidrug-resistant K.pneumoniae in N.atra suggests the increasing risk of pathogen transmission between humans,livestock,and wildlife.Given the close association between foodborne pathogenic microorganisms and humans,it is key factor to identify these antibiotic resistance genes profile thereby minimize the risk of K.pneumoniae transmission.
