Goals and Directions
Identification of ORFs necessary for antibiotic resistance or tolerance and potential vaccine targets in K. pneumoniae and P. aeruginosa.
We will begin with targets already identified from the RNA sequencing analysis of K. pneumoniae biofilms. Students will purify recombinant proteins which will then be evaluated as potential vaccine targets in conjunction with collaborators who have access to mouse models of disease. We will also generate mutants in genes of interest which we will be able to share with our collaborators or potentially use ourselves with the Galleria mellonella (waxworm) model. We are working in conjunction with Dr. Rawat (Fresno State) to understand how low molecular weight (LMW) thiols contribute to survival of P. aeruginosa under conditions of oxidative stress, such as the stress caused by antibiotic therapy. For this project, I am excited about the opportunity for students to spend some time researching what is known about antibiotic resistance in other bacterial systems and use that knowledge to begin selecting ORFs they would like to study in our pathogens of interest.
Students on this project: Michael, Chris, Preet, Justin, Navleen, Alexandra
Avian Microbiology and Nesting on the Fresno State Campus
Birds are among the most common non-human vertebrates in urban environments, and the continuing sprawl of urban habitats leads to increased possibilities for acquisition of antibiotic resistance. Close association with human habitation also increases risk for transmission of these antibiotic resistant organisms to humans through contact and contamination with fecal material. As American Crows (Corvus branchyrhyncos), members of the Corvidae, are widespread throughout North America and tend to roost in large numbers near human settlements, understanding the microbiome and potential carriage of antimicrobial resistant organisms in this species will provide important information about risks to human health in urban areas. The long-term goal of this study is to characterize the microbiome and antimicrobial resistance found in corvid feces. The central hypothesis is that birds roosting in urban environments will have more pathogenic and antimicrobial resistant organisms in their feces than birds in rural environments. The immediate objective is to identify the microbial composition and antimicrobial resistance profile of feces from urban and rural roosting crows. We are completing this project in collaboration with Dr. Katti (Fresno State) and Dr. Eisen (UC Davis). We are also interested in the avian usage of our urban/agricultural campus. Our major species of interest is the Bushtit (Psaltriparus minimus) and how incorporation of man-made materials alter the nest microbiome and overall nest success.
Students on this project: Robin and Joee
Prevalence of Tick-Borne Infections in Ticks from Recreational Areas in Fresno and Madera Counties
Tick-Borne Relapsing Fever (TBRF) is a serious vector-borne disease that is endemic to the mountains of Fresno County. The distribution and prevalence of both the bacterial agent (Borrelia spp.) and the soft-tick vector (Ornithodoros hermsi) are poorly understood in the Sierra National Forest. Our goal is to collect O. hermsi near popular recreational locations and at varying elevations within the Sierra National Forest to better understand the distribution and abundance of these ticks. Ticks will be collected using an adapted carbon dioxide (dry ice) baited trap. A series of traps will be deployed overnight near human-occupied cabins, campgrounds, and other man-made facilities in addition to the forested areas in the immediate vicinity on these locations. Traps are inexpensive and easily deployable for immediate reuse at multiple locations. We will test collected ticks for the presence of B. hermsii (and other relapsing fever causing Borrelia) in both their bodies, signifying an active infection, and separately their salivary glands, which would signify the ability of the tick to transmit the bacteria to a host animal or human. Samples will be tested using a polymerase chain reaction (PCR) amplification of the glpQ gene followed by a restriction fragment length polymorphism (RFLP) assay to determine which relapsing fever Borrelia is present in these ticks, as the glpQ is unique to relapsing fever Borrelia and absent from those causing Lyme disease. The data we collect will be used to better understand the distribution of O. hermsi and prevalence of relapsing fever Borrelia in the Sierra National Forest with the intent of assisting public health officials with possible risk assessments. If successful, these protocols can be readily adapted for use in other counties where Tick-Borne Relapsing Fever is endemic.
Students on this project: Steven
Assessing Antimicrobial Resistance and Purity in Probiotics
Probiotics are live microorganisms that provide therapeutic effects to their consuming host’s gastrointestinal tract and immune system. Although they are considered “generally recognized as safe” (GRAS) by the FDA and are added to a plethora of probiotic products, probiotics are known to display patterns of antibiotic resistance and impurity. In this study, we determined probiotic strains of Bacillus were resistant to clinically relevant antibiotics. Kirby-Bauer disc diffusion assays were performed to assess if any of these probiotic Bacillus strains were resistant to clinically relevant antibiotics. In B. coagulans and B. subtilis strains, we observed resistance and intermediate sensitivity to various antibiotics. We used the Comprehensive Antibiotic Resistance Database (CARD) to computationally analyze genomes and plasmids of these probiotic Bacillus strains and probiotics from multi-strain supplements for genes that confer antimicrobial resistance (AMR) and found genes conferring resistance to all classes of antibiotics. In addition, we assessed the purity of the active species content in multi-strain probiotics to identify which probiotic and contaminant is a potential vector of AMR. In the three supplements we found various contaminants and probiotics containing AMR genes on chromosomal and plasmidic elements. Taken together, results from this study provide insight into the potential risks of AMR and impurities in probiotic supplements.
Students on this project: Manny, Bri
Identification of ORFs necessary for antibiotic resistance or tolerance and potential vaccine targets in K. pneumoniae and P. aeruginosa.
We will begin with targets already identified from the RNA sequencing analysis of K. pneumoniae biofilms. Students will purify recombinant proteins which will then be evaluated as potential vaccine targets in conjunction with collaborators who have access to mouse models of disease. We will also generate mutants in genes of interest which we will be able to share with our collaborators or potentially use ourselves with the Galleria mellonella (waxworm) model. We are working in conjunction with Dr. Rawat (Fresno State) to understand how low molecular weight (LMW) thiols contribute to survival of P. aeruginosa under conditions of oxidative stress, such as the stress caused by antibiotic therapy. For this project, I am excited about the opportunity for students to spend some time researching what is known about antibiotic resistance in other bacterial systems and use that knowledge to begin selecting ORFs they would like to study in our pathogens of interest.
Students on this project: Michael, Chris, Preet, Justin, Navleen, Alexandra
Avian Microbiology and Nesting on the Fresno State Campus
Birds are among the most common non-human vertebrates in urban environments, and the continuing sprawl of urban habitats leads to increased possibilities for acquisition of antibiotic resistance. Close association with human habitation also increases risk for transmission of these antibiotic resistant organisms to humans through contact and contamination with fecal material. As American Crows (Corvus branchyrhyncos), members of the Corvidae, are widespread throughout North America and tend to roost in large numbers near human settlements, understanding the microbiome and potential carriage of antimicrobial resistant organisms in this species will provide important information about risks to human health in urban areas. The long-term goal of this study is to characterize the microbiome and antimicrobial resistance found in corvid feces. The central hypothesis is that birds roosting in urban environments will have more pathogenic and antimicrobial resistant organisms in their feces than birds in rural environments. The immediate objective is to identify the microbial composition and antimicrobial resistance profile of feces from urban and rural roosting crows. We are completing this project in collaboration with Dr. Katti (Fresno State) and Dr. Eisen (UC Davis). We are also interested in the avian usage of our urban/agricultural campus. Our major species of interest is the Bushtit (Psaltriparus minimus) and how incorporation of man-made materials alter the nest microbiome and overall nest success.
Students on this project: Robin and Joee
Prevalence of Tick-Borne Infections in Ticks from Recreational Areas in Fresno and Madera Counties
Tick-Borne Relapsing Fever (TBRF) is a serious vector-borne disease that is endemic to the mountains of Fresno County. The distribution and prevalence of both the bacterial agent (Borrelia spp.) and the soft-tick vector (Ornithodoros hermsi) are poorly understood in the Sierra National Forest. Our goal is to collect O. hermsi near popular recreational locations and at varying elevations within the Sierra National Forest to better understand the distribution and abundance of these ticks. Ticks will be collected using an adapted carbon dioxide (dry ice) baited trap. A series of traps will be deployed overnight near human-occupied cabins, campgrounds, and other man-made facilities in addition to the forested areas in the immediate vicinity on these locations. Traps are inexpensive and easily deployable for immediate reuse at multiple locations. We will test collected ticks for the presence of B. hermsii (and other relapsing fever causing Borrelia) in both their bodies, signifying an active infection, and separately their salivary glands, which would signify the ability of the tick to transmit the bacteria to a host animal or human. Samples will be tested using a polymerase chain reaction (PCR) amplification of the glpQ gene followed by a restriction fragment length polymorphism (RFLP) assay to determine which relapsing fever Borrelia is present in these ticks, as the glpQ is unique to relapsing fever Borrelia and absent from those causing Lyme disease. The data we collect will be used to better understand the distribution of O. hermsi and prevalence of relapsing fever Borrelia in the Sierra National Forest with the intent of assisting public health officials with possible risk assessments. If successful, these protocols can be readily adapted for use in other counties where Tick-Borne Relapsing Fever is endemic.
Students on this project: Steven
Assessing Antimicrobial Resistance and Purity in Probiotics
Probiotics are live microorganisms that provide therapeutic effects to their consuming host’s gastrointestinal tract and immune system. Although they are considered “generally recognized as safe” (GRAS) by the FDA and are added to a plethora of probiotic products, probiotics are known to display patterns of antibiotic resistance and impurity. In this study, we determined probiotic strains of Bacillus were resistant to clinically relevant antibiotics. Kirby-Bauer disc diffusion assays were performed to assess if any of these probiotic Bacillus strains were resistant to clinically relevant antibiotics. In B. coagulans and B. subtilis strains, we observed resistance and intermediate sensitivity to various antibiotics. We used the Comprehensive Antibiotic Resistance Database (CARD) to computationally analyze genomes and plasmids of these probiotic Bacillus strains and probiotics from multi-strain supplements for genes that confer antimicrobial resistance (AMR) and found genes conferring resistance to all classes of antibiotics. In addition, we assessed the purity of the active species content in multi-strain probiotics to identify which probiotic and contaminant is a potential vector of AMR. In the three supplements we found various contaminants and probiotics containing AMR genes on chromosomal and plasmidic elements. Taken together, results from this study provide insight into the potential risks of AMR and impurities in probiotic supplements.
Students on this project: Manny, Bri
