Pechal, Jennifer (2008-08). Intraspecific Gene Flow and Vector Competence among Periplaneta americana Cockroaches (Blattodea: Blattidae) in Central Texas. Master's Thesis. Thesis uri icon

abstract

  • One of the most overlooked areas in forensic entomology is urban, which applies to insects and their arthropod relatives that have interactions with humans, their associated structures, and companion animals. American cockroaches, Periplaneta americana (L.), are common pests of urban environments. Analyzing spatial distribution of P. americana populations in an artificial, outdoor environment provided insight of gene flow among populations collected in central Texas. This information provides for a better understanding of how and if populations were segregated, or if there was a single unified population. Populations can be genetically differentiated through determining variation of specific gene regions within populations. This study revealed a ubiquitous distribution of cockroach populations, and their ability to indiscriminately inhabit areas within an urban environment. Overall, cockroaches were identified from a large interbreeding population with no discernable relationship between genetic variation of P. americana and spatial distribution. Identifying cockroach populations is relative to understanding the ability of surrogate species indirectly affecting man by their ability to transfer disease-causing organisms including bacteria. This may have potentially deleterious health consequences on animal and/or human populations. There are several pathogens associated with cockroaches which are overlooked during diagnosis of sudden ailments with symptoms being similar to food-borne illnesses, including abdominal cramping, diarrhea, nausea, and fever. Analyzing spatial distributions of Escherichia coli and Campylobacter spp. in relationship to collected cockroaches allowed for prevalence of bacteria species to be identified among populations. The prevalence of bacteria isolated from total populations collected indicated a high prevalence (92.3%) of bacteria carried by the exoskeleton of P. americana. Gram-negative bacteria acquisition and dissemination of organisms such as E. coli was prevalent on campus. Screening for E. coli 1057:H7 and Campylobacter spp. resulted in no positive colony growth. The lack of Campylobacter spp. growth from cuticular surfaces may have resulted from undesirable conditions required to sustain colony growth. Data from this study corroborates the potential ability of cockroaches to mechanically transmit pathogens.
  • One of the most overlooked areas in forensic entomology is urban, which applies
    to insects and their arthropod relatives that have interactions with humans, their
    associated structures, and companion animals. American cockroaches, Periplaneta
    americana (L.), are common pests of urban environments. Analyzing spatial distribution
    of P. americana populations in an artificial, outdoor environment provided insight of
    gene flow among populations collected in central Texas. This information provides for a
    better understanding of how and if populations were segregated, or if there was a single
    unified population. Populations can be genetically differentiated through determining
    variation of specific gene regions within populations. This study revealed a ubiquitous
    distribution of cockroach populations, and their ability to indiscriminately inhabit areas
    within an urban environment. Overall, cockroaches were identified from a large
    interbreeding population with no discernable relationship between genetic variation of P.
    americana and spatial distribution.
    Identifying cockroach populations is relative to understanding the ability of
    surrogate species indirectly affecting man by their ability to transfer disease-causing organisms including bacteria. This may have potentially deleterious health consequences
    on animal and/or human populations. There are several pathogens associated with
    cockroaches which are overlooked during diagnosis of sudden ailments with symptoms
    being similar to food-borne illnesses, including abdominal cramping, diarrhea, nausea,
    and fever. Analyzing spatial distributions of Escherichia coli and Campylobacter spp. in
    relationship to collected cockroaches allowed for prevalence of bacteria species to be
    identified among populations. The prevalence of bacteria isolated from total populations
    collected indicated a high prevalence (92.3%) of bacteria carried by the exoskeleton of
    P. americana. Gram-negative bacteria acquisition and dissemination of organisms such
    as E. coli was prevalent on campus. Screening for E. coli 1057:H7 and Campylobacter
    spp. resulted in no positive colony growth. The lack of Campylobacter spp. growth from
    cuticular surfaces may have resulted from undesirable conditions required to sustain
    colony growth. Data from this study corroborates the potential ability of cockroaches to
    mechanically transmit pathogens.

publication date

  • August 2008