Cockroaches are worldwide indoor pests carrying microorganisms of medical importance. German cockroaches （Blattella germanica） were sampled in five habitats （hospital, restaurant, office home, and market） in Beiji...Cockroaches are worldwide indoor pests carrying microorganisms of medical importance. German cockroaches （Blattella germanica） were sampled in five habitats （hospital, restaurant, office home, and market） in Beijing, and the bacteria were isolated from their external surface and alimentary tract and identified using a Biolog identification system. Cockroach densities significantly differed among habitats （market 〉 home 〉 office 〉 restaurant 〉 hospital）. However, no significant differences in bacterial abundance carried by individual German cockroaches （of either sex） were found among habitats. The bacterial abundance in the gut was significantly higher than that on the surface. There were no significant differences in bacterial species richness observed among habitats, sex, carrying position or their interaction. Cluster analysis showed that cockroach densities and bacterial abundance found in the market differed significantly from the other four habitats. The bacterial diversity was not significantly reduced in sensitive facilities such as hospital and restaurant, even though pesticide and bactericide were more frequently applied there. The implications of these findings were discussed in this article.展开更多
A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Thr...A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Three major bacterial groups were cultured （total aerobic, enterobacteria, and staphylococci） from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable （P〈0.001） and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of （2.1×10^5 CFU/insect）, whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.展开更多
Volatile sex pheromones are vital for sexual communication between males and females.Females of the American cockroach,Periplaneta americana,produce and emit two sex pheromone components,periplanone-A(PA)and periplano...Volatile sex pheromones are vital for sexual communication between males and females.Females of the American cockroach,Periplaneta americana,produce and emit two sex pheromone components,periplanone-A(PA)and periplanone-B(PB).Although PB is the major sex attractant and can attract males,how it interacts with PA in regulating sexual behaviors is still unknown.In this study,we found that in male cockroaches,PA counteracted PB attraction.We identified two odorant receptors(ORs),OR53 and OR100,as PB/PA and PA receptors,respectively.OR53 and OR100 were predominantly expressed in the antennae of sexually mature males,and their expression levels were regulated by the sex differentiation pathway and nutrition-responsive signals.Cellular localization of OR53 and OR100 in male antennae further revealed that two types of sensilla coordinate a complex two-pheromone-two-receptor pathway in regulating cockroach sexual behaviors.These findings indicate distinct functions of the two sex pheromone components,identify their receptors and possible regulatory mechanisms underlying the male-specific and age-dependent sexual behaviors,and can guide novel strategies for pest management.展开更多
基金supported by the Knowledge Innovation Program of CAS (No. KZCX2-YW-422)the Open Fund of State Key Laboratory of Urban and Regional Ecology.
文摘Cockroaches are worldwide indoor pests carrying microorganisms of medical importance. German cockroaches （Blattella germanica） were sampled in five habitats （hospital, restaurant, office home, and market） in Beijing, and the bacteria were isolated from their external surface and alimentary tract and identified using a Biolog identification system. Cockroach densities significantly differed among habitats （market 〉 home 〉 office 〉 restaurant 〉 hospital）. However, no significant differences in bacterial abundance carried by individual German cockroaches （of either sex） were found among habitats. The bacterial abundance in the gut was significantly higher than that on the surface. There were no significant differences in bacterial species richness observed among habitats, sex, carrying position or their interaction. Cluster analysis showed that cockroach densities and bacterial abundance found in the market differed significantly from the other four habitats. The bacterial diversity was not significantly reduced in sensitive facilities such as hospital and restaurant, even though pesticide and bactericide were more frequently applied there. The implications of these findings were discussed in this article.
文摘A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Three major bacterial groups were cultured （total aerobic, enterobacteria, and staphylococci） from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable （P〈0.001） and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of （2.1×10^5 CFU/insect）, whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.
基金supported by the National Natural Science Foundation of China(32220103003,31930014,31900355,31970943 and 32000334)the Department of Science and Technology in Guangdong Province(2022A1515011759)+2 种基金the Laboratory of Lingnan Modern Agriculture Project(NT2021003)by the Department of Science and Technology in Guangdong Province(2019B090905003)by the Shenzhen Science and Technology Program(KQTD20180411143628272)。
文摘Volatile sex pheromones are vital for sexual communication between males and females.Females of the American cockroach,Periplaneta americana,produce and emit two sex pheromone components,periplanone-A(PA)and periplanone-B(PB).Although PB is the major sex attractant and can attract males,how it interacts with PA in regulating sexual behaviors is still unknown.In this study,we found that in male cockroaches,PA counteracted PB attraction.We identified two odorant receptors(ORs),OR53 and OR100,as PB/PA and PA receptors,respectively.OR53 and OR100 were predominantly expressed in the antennae of sexually mature males,and their expression levels were regulated by the sex differentiation pathway and nutrition-responsive signals.Cellular localization of OR53 and OR100 in male antennae further revealed that two types of sensilla coordinate a complex two-pheromone-two-receptor pathway in regulating cockroach sexual behaviors.These findings indicate distinct functions of the two sex pheromone components,identify their receptors and possible regulatory mechanisms underlying the male-specific and age-dependent sexual behaviors,and can guide novel strategies for pest management.
