Pathogens Of Public Health Significance Research Articles

Genomic and Phenotypic Analysis of Salmonella enterica Bacteriophages Identifies Two Novel Phage Species.

Bacteriophages (phages) are potential alternatives to chemical antimicrobials against pathogens of public health significance. Understanding the diversity and host specificity of phages is important for developing effective phage biocontrol approaches. Here, we assessed the host range, morphology, and genetic diversity of eight Salmonella enterica phages isolated from a wastewater treatment plant. The host range analysis revealed that six out of eight phages lysed more than 81% of the 43 Salmonella enterica isolates tested. The genomic sequences of all phages were determined. Whole-genome sequencing (WGS) data revealed that phage genome sizes ranged from 41 to 114 kb, with GC contents between 39.9 and 50.0%. Two of the phages SB13 and SB28 represent new species, Epseptimavirus SB13 and genera Macdonaldcampvirus, respectively, as designated by the International Committee for the Taxonomy of Viruses (ICTV) using genome-based taxonomic classification. One phage (SB18) belonged to the Myoviridae morphotype while the remaining phages belonged to the Siphoviridae morphotype. The gene content analyses showed that none of the phages possessed virulence, toxin, antibiotic resistance, type I-VI toxin-antitoxin modules, or lysogeny genes. Three (SB3, SB15, and SB18) out of the eight phages possessed tailspike proteins. Whole-genome-based phylogeny of the eight phages with their 113 homologs revealed three clusters A, B, and C and seven subclusters (A1, A2, A3, B1, B2, C1, and C2). While cluster C1 phages were predominantly isolated from animal sources, cluster B contained phages from both wastewater and animal sources. The broad host range of these phages highlights their potential use for controlling the presence of S. enterica in foods.

Microbiological Contamination of Fermented Cassava Products Sold in Local Markets, Yaounde (Cameroon)

Locally processed cassava is a desirable staple food in Cameroon; however, microbiological hazards during processing, handling and/or consumption have been significantly ignored. This study investigated the microbiological quality of five fermented cassava products locally called Kum-kum, Garri, Water-fufu, Bobolo and Mintoumba, which are widely consumed and sold in local markets across Yaounde. A total of 200 samples (n=40 per food product) were analysed using microbial culture techniques. In addition, three parameters, moisture content, water activity, and pH were measured as indicators of each product shelf-life. The results showed that all food types were slightly acidic, ranging between 4.1 (Water-fufu) and 6.3 (Garri). Moisture and water activity were highest in Water-fufu (58.52% and 0.94) and lowest in Kum-kum (3.35% and 0.51) respectively. The presence of E. coli and coliforms (5.61log10 CFU/g to 8.67log10 CFU/g) indicated potential faecal contamination and improper product storage. Specifically, the mean total viable bacteria, yeast and mould count indicated unsatisfactory levels for human consumption and ranged from 5.33log10 CFU/g (Mintoumba) to 7.22log10 CFU/g (Water-fufu), and 4.23log10 CFU/g (Garri) to 6.59log10 CFU/g (Kum-kum) respectively. In terms of foodborne pathogens, all cassava products contained at least one pathogen of public health significance. Water-fufu significantly contained Bacillus cereus (33%), Vibrio cholerae (28%), Salmonella spp. (23%) and Campylobacter spp. (13%), and Staphylococci and Listeria monocytogenes were most prevalent in Kum-kum at 21% and 13% respectively. The results showed the short shelf-life characteristics of fermented cassava products consumed in Cameroon, and importantly, indicated a significant route of human exposure to enteric pathogens.

Cell-based passive immunization for protection against SARS-CoV-2 infection

BackgroundImmunologically impaired individuals respond poorly to vaccines, highlighting the need for additional strategies to protect these vulnerable populations from COVID-19. While monoclonal antibodies (mAbs) have emerged as promising tools to manage infectious diseases, the transient lifespan of neutralizing mAbs in patients limits their ability to confer lasting, passive prophylaxis from SARS-CoV-2. Here, we attempted to solve this problem by combining cell and mAb engineering in a way that provides durable immune protection against viral infection using safe and universal cell therapy.MethodsMouse embryonic stem cells equipped with our FailSafe™ and induced allogeneic cell tolerance technologies were engineered to express factors that potently neutralize SARS-CoV-2, which we call ‘neutralizing biologics’ (nBios). We subcutaneously transplanted the transgenic cells into mice and longitudinally assessed the ability of the cells to deliver nBios into circulation. To do so, we quantified plasma nBio concentrations and SARS-CoV-2 neutralizing activity over time in transplant recipients. Finally, using similar cell engineering strategies, we genetically modified FailSafe™ human-induced pluripotent stem cells to express SARS-CoV-2 nBios.ResultsTransgenic mouse embryonic stem cells engineered for safety and allogeneic-acceptance can secrete functional and potent SARS-CoV-2 nBios. As a dormant, subcutaneous tissue, the transgenic cells and their differentiated derivatives long-term deliver a supply of protective nBio titers in vivo. Moving toward clinical relevance, we also show that human-induced pluripotent stem cells, similarly engineered for safety, can secrete highly potent nBios.ConclusionsTogether, these findings show the promise and potential of using ‘off-the-shelf’ cell products that secrete neutralizing antibodies for sustained protective immunity against current and future viral pathogens of public health significance.

Exploration of Infant Food Microbial Composition from Formal and Informal Settings Using Viable Counts and 16S rRNA Gene Amplicon Sequencing in Johannesburg, South Africa.

Diarrhoea is a considerable agent of disease and loss of life in children below age five in South Africa. Soweto, South Africa is an urban township in Johannesburg, with most of its population living in informal settlements. Informal settlements in areas such as Soweto are often impoverished communities that do not get water easily, inadequate sanitation is pervasive, and poor hygiene common (risk factors for diarrhoeal diseases). Among the age groups, infants are most vulnerable to diarrhoeal infection, mainly through the ingestion of food and water. The presence of undesirable microbiota is a food safety and health challenge. This study investigated the microbiome of infant food samples collected from formal (n = 19) and informal (n = 11) households in Soweto. A non-culture-dependent technique was used to characterise the bacterial diversity and composition of the infant food samples. The results indicated that household type did not influence microbial diversity and composition in Soweto. South Africa. Firmicutes, Proteobacteria, Cyanobacteria, and Tenericutes dominated the phyla rank in food samples from formal and informal households. Potential pathogens of public health significance, including diarrhoeal disease agents such as Salmonella spp., E. coli, and Campylobacter spp., were detected within the foods. We concluded that the infant food samples showed rich bacterial diversity, and the presence of potential pathogens of public health significance suggests a disease risk that infants may face upon consuming the foods.

Risk factors associated with the prevalence of Listeria monocytogenes in manured soils on certified organic farms in four regions of the United States

IntroductionBiological soil amendments, including raw or untreated manure, are currently used to improve soil fertility, especially in organic operations that prohibit use of synthetic fertilizers. However, addition of untreated manure may pose a risk of contamination of fresh produce by pathogens of public health significance, including Listeria monocytogenes. Organic growers follow United States Department of Agriculture (USDA) National Organic Program regulations for raw manure use, which stipulate that harvest should commence no earlier than 90- or 120-days post-application, depending on direct contact between the edible portion of the produce and the soil. To inform the protection that such time-intervals provide, this study explored the farm-level risk factors associated with L. monocytogenes prevalence in USDA-certified organic farm soils amended with untreated manures.MethodsA longitudinal, multi-regional study was conducted on 19 farms in four states (California, Minnesota, Maine, and Maryland) over two growing seasons (2017 and 2018). Untreated manure, soil, irrigation water, and produce samples were collected and cultured for L. monocytogenes. Mixed effect logistic regression was used to investigate risk factors associated with L. monocytogenes prevalence in soil.Results and DiscussionResults showed that multiple factors influenced the odds of a soil-positive sample, including temporal [year (OR = 0.19), sampling day (OR = 0.09–0.48)] and weather-related [temperature range (OR = 0.48)] variables, manure characteristics [season of application (OR = 0.04, summer), presence of L. monocytogenes (OR = 2.89) and other pathogens in manure (OR = 5.24)], farm management factors [water source (OR = 2.73, mixed), number of year-round staff (OR = 0.02)], and soil characteristics [concentration of generic Escherichia coli (OR = 1.45), moisture (OR = 0.46), organic matter (OR = 7.30), nitrate (OR = 3.07), potassium (OR = 0.09) and calcium (OR = 2.48)]. This study highlights the complexity of L. monocytogenes prevalence in soil and contributes science-based metrics that may be used when determining risk-mitigation strategies for pathogen contamination.

Growth and survival characteristics of Listeria monocytogenes of different sources and subtypes

Listeria monocytogenes is a foodborne pathogen of public health significance. The most popular pathogen subtypes isolated from food are different from those of clinical isolates. Understanding the behavior of L. monocytogenes along the food chain is important for risk assessment. The objective of this study was to describe the growth and survival characteristics of L. monocytogenes strains and evaluate their association with different subtypes. Food (n = 10) and clinical (n = 4) isolates and one reference strain (ATCC19112) were selected. The growth and survival characteristics of L. monocytogenes was monitored. It showed that the ST5 strains had adaptive capacity in weak acid and alkali, strong resistance to heat stress, violent acid and hypertonic. The serogroup IIb and IIa exhibited the highest acid resistance and bile salt tolerance, respectively. Furthermore, the ST8 and ST9 strains exhibited strong resistance in the bile salt environment and poor growth ability in the low salt broth, respectively. The ST87 food isolate had strong resistance to hypertonic and acid environments. Although further research for more L. monocytogenes strains is needed, the findings of this study should be useful in understanding the growth and survival behavior of L. monocytogenes belonging to different subgroups.

Mutations in the Quinolones Resistance Determining Regions of gyrA in Nosocomial Staphylococcus aureus and Salmonella typhi

In Nigeria, Staphylococcus aureus and Salmonella typhi are common causes of human infections and are also recognized as pathogens of public health significance. This study therefore, sought to determine the incidence and extent of fluoroquinolones resistance of S. typhi and S. aureus isolated from patients in Nigerian Defence Academy Hospital. A total of 60 samples obtained from patients with request for stool microscopy, culture and sensitivity, wound swabs, indoor air of surgical wards and swabbing of working benches were analyzed for the presence of S. aureus and S. typhi. The bacterial isolates were then subjected to antibiotic sensitivity testing using a modified Kirby-Bauer disk diffusion method. The antibiotic susceptibility patterns of S. typhi revealed that some of the isolates were resistant to two or more fluoroquinolones namely: ciprofloxacin, sparfloxacin, ofloxacin and pefloxacin. S. aureus on the other hand, also showed resistance to fluoroquinolones. The isolates that showed resistance to more fluoroquinolones were taken for molecular analysis. The genomic DNA was extracted and amplified using specific primer for gyrA by PCR, visualized using agarose gel electrophoresis and then sequenced. The amplicon sizes were 251bp respectively for each of the isolates. The detection of resistant pattern responsible for fluoroquinolones resistance showed that mutation had occurred. Mutation in nucleotide sequence was detected in gyrA gene of the fluoroquinolone resistant strains.

Antimicrobial Resistance Rates and Surveillance in Sub-Saharan Africa: Where Are We Now?

IntroductionAlthough antimicrobials have traditionally been used to treat infections and improve health outcomes, resistance to commonly used antimicrobials has posed a major challenge. An estimated 700,000 deaths occur globally every year as a result of infections caused by antimicrobial-resistant pathogens. Antimicrobial resistance (AMR) also contributes directly to the decline in the global economy. In 2019, sub-Saharan Africa (SSA) had the highest mortality rate (23.5 deaths per 100,000) attributable to AMR compared to other regions.MethodsWe searched PubMed for articles relevant to AMR in pathogens in the WHO-GLASS list and in other infections of local importance in SSA. In this review, we focused on AMR rates and surveillance of AMR for these priority pathogens and some of the most encountered pathogens of public health significance. In addition, we reviewed the implementation of national action plans to mitigate against AMR in countries in SSA.Results and DiscussionThe SSA region is disproportionately affected by AMR, in part owing to the prevailing high levels of poverty, which result in a high burden of infectious diseases, poor regulation of antimicrobial use, and a lack of alternatives to ineffective antimicrobials. The global action plan as a strategy for prevention and combating AMR has been adopted by most countries, but fewer countries are able to fully implement country-specific action plans, and several challenges exist in many settings.ConclusionA concerted One Health approach will be required to ramp up implementation of action plans in the region. In addition to AMR surveillance, effective implementation of infection prevention and control, water, sanitation, and hygiene, and antimicrobial stewardship programs will be key cost-effective strategies in helping to tackle AMR.

Sero-prevalence and risk factors for Brucella melitensis infection in goats slaughtered in Abuja metropolis, Nigeria

Brucellosis is a disease that causes significant reproductive failure in ruminants and has been reported to be a disease of major zoonotic importance. The aim of this study was to determine the seroprevalence and risk factors for Brucella melitensis infection in goats slaughtered in the Abattoir section of the Livestock Market Gwagwalada Area Council, Anagada, Abuja Nigeria. A total of 240 blood samples were collected in plain tubes without anti-coagulant at point of slaughter for the harvesting of serum samples. Serum Agglutination Test with EDTA (SAT-EDTA) and Lateral Flow Assay (LFA) were used to test for exposure to Brucella infection. Chi square was used to test for association between catergorical variables as with level of significance set at 0.05. Overall seroprevalence rates using SAT-EDTA and LFA were 7.11% and 6.67% respectively. Based on risk factors, seroprevalence rate was higher in does (6.62% vs 6.68%), goats ≤ 1 year of age (7.45% vs 7.45%) and the Sahel breed of goats (9.80% vs 7.69%) by SAT-EDTA and LFA respectively. There was no significant difference between all variables p > 0.05. Highest prevalence rates were obtained in does, goats ≤ 1 year and the Sahel breed of goats. As a pathogen of public health significance to in-contact abattoir workers, it is imperative that these workers be educated on the nature of the disease and on how to minimize its risk of transmission via contacted with infected animals and their products.

Sero-prevalence and risk factors for Brucella melitensis infection in goats slaughtered in Abuja metropolis, Nigeria

Brucellosis is a disease that causes significant reproductive failure in ruminants and has been reported to be a disease of major zoonotic importance. The aim of this study was to determine the seroprevalence and risk factors for Brucella melitensis infection in goats slaughtered in the Abattoir section of the Livestock Market Gwagwalada Area Council, Anagada, Abuja Nigeria. A total of 240 blood samples were collected in plain tubes without anti-coagulant at point of slaughter for the harvesting of serum samples. Serum Agglutination Test with EDTA (SAT-EDTA) and Lateral Flow Assay (LFA) were used to test for exposure to Brucella infection. Chi square was used to test for association between catergorical variables as with level of significance set at 0.05. Overall seroprevalence rates using SAT-EDTA and LFA were 7.11% and 6.67% respectively. Based on risk factors, seroprevalence rate was higher in does (6.62% vs 6.68%), goats ≤ 1 year of age (7.45% vs 7.45%) and the Sahel breed of goats (9.80% vs 7.69%) by SAT-EDTA and LFA respectively. There was no significant difference between all variables p > 0.05. Highest prevalence rates were obtained in does, goats ≤ 1 year and the Sahel breed of goats. As a pathogen of public health significance to in-contact abattoir workers, it is imperative that these workers be educated on the nature of the disease and on how to minimize its risk of transmission via contacted with infected animals and their products.

Recently Evolved Francisella-Like Endosymbiont Outcompetes an Ancient and Evolutionarily Associated Coxiella-Like Endosymbiont in the Lone Star Tick (Amblyomma americanum) Linked to the Alpha-Gal Syndrome.

BackgroundTicks are hematophagous arthropods that transmit various bacterial, viral, and protozoan pathogens of public health significance. The lone star tick (Amblyomma americanum) is an aggressive human-biting tick that transmits bacterial and viral pathogens, and its bites are suspected of eliciting the alpha-gal syndrome, a newly emerged delayed hypersensitivity following consumption of red meat in the United States. While ongoing studies have attempted to investigate the contribution of different tick-inherent factors to the induction of alpha-gal syndrome, an otherwise understudied aspect is the contribution of the tick microbiome and specifically obligate endosymbionts to the establishment of the alpha-gal syndrome in humans.Materials and MethodsHere we utilized a high-throughput metagenomic sequencing approach to cataloging the entire microbial communities residing within different developmental stages and tissues of unfed and blood-fed ticks from laboratory-maintained ticks and three new geographical locations in the United States. The Quantitative Insights Into Microbial Ecology (QIIME2) pipeline was used to perform data analysis and taxonomic classification. Moreover, using a SparCC (Sparse Correlations for Compositional data) network construction model, we investigated potential interactions between members of the microbial communities from laboratory-maintained and field-collected ticks.ResultsOverall, Francisellaceae was the most dominant bacteria identified in the microbiome of both laboratory-raised and field-collected Am. americanum across all tissues and developmental stages. Likewise, microbial diversity was seen to be significantly higher in field-collected ticks compared with laboratory-maintained ticks as seen with a higher number of both Operational Taxonomic Units and measures of species richness. Several potential positive and negative correlations were identified from our network analysis. We observed a strong positive correlation between Francisellaceae, Rickettsiaceae, and Midichloriaceae in both developmental stages and tissues from laboratory-maintained ticks, whereas ovarian tissues had a strong positive correlation of bacteria in the family Xanthobacteraceae and Rhizobiaceae. A negative interaction was observed between Coxiellaceae and Francisellaceae in Illinois, and all the bacteria detected from ticks from Delaware were negatively correlated.ConclusionThis study is the first to catalog the microbiome of Am. americanum throughout its developmental stages and different tissue niches and report the potential replacement of Coxiellaceae by Francisellaceae across developmental stages and tissues tested except in ovarian tissues. These unique and significant findings advance our knowledge and open a new avenue of research to further understand the role of tick microbiome in tick-borne diseases and develop a holistic strategy to control alpha-gal syndrome.

Seafood associated bacterial pathogens of public health significance: A brief review

Seafood associated bacterial pathogens of public health significance: A brief review

3′UTR SL-IV and DB1 Regions Contribute to Japanese Encephalitis Virus Replication and Pathogenicity

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus that causes fatal neurological disease in humans, is one of the most important emerging pathogens of public health significance. JEV is maintained in an enzootic cycle and causes reproductive failure in pigs. Notably, the shift in JEV genotypes is not fully protected by existing vaccines, so the development of a candidate vaccine is urgently needed. In this study, we compared pathogenicity between Japanese encephalitis virus SA14 and BJB (isolated from humans in the 1970s) strains. We found that the BJB strain was attenuated in mice and that there was no case fatality rate. The growth rate of BJB was higher than SA14 virus in BHK-21 cells. Based on the sequence alignment of the viral genome between the SA14 and BJB virus strains, some mutations at sites 248, 254, 258, and 307 were observed in the 3′ untranslated region (3′UTR). The 3′UTR of JEV plays a very important role in the viral life cycle. Furthermore, using a reverse genetic system, we conducted and rescued the parental JEV strain SA14 (T248, A254, and A258) and the mutant virus rSA14-3′UTRmut (T248C, A254G, A258G, and 307G). Through an analysis of the RNA secondary structure model of the 3′UTR, we discovered that the mutations of T248C, A254G, and A258G reduced the apiculus ring and increased the lateral ring significantly in the stem-loop structures IV (SL-IV) structure region of 3′UTR. Moreover, the insertion of 307G added a ring to the dumbbell structure 1 (DB1) structure region. Strikingly, these RNA secondary structure changes in 3′UTR of rSA14-3′UTRmut increased viral negative chain RNA production and enhanced the replication ability of the virus in BHK-21 cells. However, in vivo mouse experiments illustrated that the rSA14-3′UTRmut virus significantly decreased the neurovirulence of JEV. These results affirmed that the JEV SL-IV and DB1 regions play an important role in viral proliferation and pathogenicity. Taken together, we complement the study of RNA element function in the 3′UTR region of JEV by providing a new target for the rational design of live attenuated candidate vaccines and the increase of virus production.

Clostridium difficile as an Emerging Foodborne Pathogen of Public Health Significance

Clostridium difficile as an Emerging Foodborne Pathogen of Public Health Significance

Recent advances in understanding tick and rickettsiae interactions.

Ticks are haematophagous arthropods with unique molecular mechanisms for digesting host blood meal while acting as vectors for various pathogens of public health significance. The tick's pharmacologically active saliva plays a fundamental role in modulating the host's immune system for several days to weeks, depending on the tick species. The vector tick has also developed sophisticated molecular mechanisms to serve as a competent vector for pathogens, including the spotted fever group (SFG) rickettsiae. Evidence is still inadequate concerning tick-rickettsiae-host interactions and saliva-assisted transmission of the pathogen to the mammalian host. Rickettsia parkeri, of the SFG rickettsia, can cause a milder version of Rocky Mountain spotted fever known as American Boutonneuse fever. The Gulf Coast tick (Amblyomma maculatum) often transmits this pathogenic rickettsia in the USA. This review discusses the knowledge gap concerning tick-rickettsiae-host interactions by highlighting the SFG rickettsia and the Ammaculatum model system. Filling this knowledge gap will provide a better understanding of the tick-rickettsiae-host interactions in disease causation, which will be crucial for developing effective methods for preventing tick-borne diseases.

A Review of Streptococcus pyogenes: Public Health Risk Factors, Prevention and Control.

Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of public health significance, infecting 18.1 million people worldwide and resulting in 500,000 deaths each year. This review identified published articles on the risk factors and public health prevention and control strategies for mitigating GAS diseases. The pathogen causing GAS diseases is commonly transmitted via respiratory droplets, touching skin sores caused by GAS or through contact with contaminated material or equipment. Foodborne transmission is also possible, although there is need for further research to quantify this route of infection. It was found that GAS diseases are highly prevalent in developing countries, and among indigenous populations and low socioeconomic areas in developed countries. Children, the immunocompromised and the elderly are at the greatest risk of S. pyogenes infections and the associated sequelae, with transmission rates being higher in schools, kindergartens, hospitals and residential care homes. This was attributed to overcrowding and the higher level of social contact in these settings. Prevention and control measures should target the improvement of living conditions, and personal and hand hygiene. Adherence to infection prevention and control practices should be emphasized in high-risk settings. Resource distribution by governments, especially in developed countries, should also be considered.

A brief overview of emergencies and dissemination of Shiga-toxin-producing E. coli (STEC) and Salmonella enterica serovar Typhimurium DT104 in humans and food producing animals

Shiga-toxin-producing Escherichia coli (STEC) and Salmonella enterica serovar Typhimurium (STDT104) are foodborne pathogens of public health significance. It is less known that Shiga-toxin-producing Escherichia coli (with cattle being the most probable natural reservoir) can be isolated from pigs, sheep and wildlife as well. The basic information about detection of Shiga-toxin-producing genes in STEC as well as the origin of Salmonella Typhimurium definite phage type 4 (STDT4) the virulence and resistance mechanisms including their distribution in the world is presented. Due to the foodborne transmission mechanisms we emphasize the role of veterinary scientist in Serbia in implementing good management practice on animal farms and in strengthening laboratory diagnostic capacities.

Borrelia miyamotoi strain LB-2001 retains plasmids and infectious phenotype throughout continuous culture passages as evaluated by multiplex PCR

Borrelia miyamotoi is a tick-borne spirochete of the relapsing fever borrelia group and an emerging pathogen of public health significance. The genomes of relapsing fever borreliae and Lyme disease borreliae consist of multiple linear and circular plasmids in addition to the chromosome. Previous work with B. burgdorferi sensu lato found diminished infectivity upon continuous in vitro culture passage that was attributable to plasmid loss. The effect of long-term culture passage on B. miyamotoi is not known. We generated a series of plasmid-specific primer sets and developed a multiplex PCR assay to detect the 14 known plasmids of B. miyamotoi North American strains LB-2001 and CT13−2396. We assessed the plasmid content of B. miyamotoi LB-2001 over 64 culture passages spanning 15 months and determined that strain LB-2001 retained all plasmids upon prolonged in vitro cultivation and remained infectious in mice. We also found that strain LB-2001 lacks plasmid lp20−1 which is present in strain CT13−2396. These results suggest that B. miyamotoi remains genetically stable when cultured and passaged in vitro.

Cyclic voltammetry, photocatalytic and antimicrobial comparative studies of fabrication Fe3O4 and Fe3O4/PAN nanofibers

This study reports the properties of green mediated synthesized iron oxides nanoparticles (Fe3O4 NPs) from peel extracts of pomegranate plant and its polyacrylonitrile/iron oxide composite nanofibers (Fe3O4/PAN). The following were used to characterize the synthesized nanoparticles and its polymer nanofibers; FT-IR, UV-Visible spectroscopy, scanning electron microscope SEM, TEM and cyclic voltammetry. The antimicrobial activities of synthesized nanoparticles were investigated against selected bacterial pathogens. For the plant extract, FTIR revealed OH characteristics peaks at 3271 cm−1 and 1600 cm−1 while the absorption peaks at 577 and 430 cm1 showed successful reduction of the precursor to Fe3O4 nanoparticles. The SEM images showed a spherical morphology of Fe3O4 and that of the composite with entrapped Fe3O4 into the PAN nanofibers. Photocatalytic process showed that the synthesized Fe3O4 nanoparticles has degradation efficiency of 71.36% and the nanofibers exhibited efficiency of 22.68% towards methylene blue (MB) dye. However, further kinetic analysis of the degradation process put Fe3O4/PAN nanofibers (NF) at a better correlation coefficient of 0.9239 than the Fe3O4 nanoparticles. Electrochemical studies using cyclic voltammetry showed that PAN functionalized with Fe3O4 is more electroactive as compared to the other electrodes studied. The anodic peak potential at 599 mV also confirmed the presence of Fe3O4 in the nanocomposite Fe3O4/PAN. The antimicrobial studies revealed that as the concentration of the green mediated Fe3O4 nanoparticle increases in the composite Fe3O4/PAN an excellent antimicrobial activity against selected pathogens were observed, showing Fe3O4 nanoparticles potentials to control pathogens of public health significance.

Longitudinal Study of Bacterial Infectious Agents in a Community of Small Mammals in New Mexico.

Background and Objectives: Vector-borne bacterial diseases represent a substantial public health burden and rodents have been recognized as important reservoir hosts for many zoonotic pathogens. This study investigates bacterial pathogens in a small mammal community of the southwestern United States of America. Methods: A total of 473 samples from 13 wild rodent and 1 lagomorph species were tested for pathogens of public health significance: Bartonella, Brucella, Yersinia, Borrelia, Rickettsia spp., and Anaplasma phagocytophilum. Results: Three animals were positive for Yersinia pestis, and one Sylvilagus audubonii had a novel Borrelia sp. of the relapsing fever group. No Brucella, Rickettsia, or A. phagocytophilum infections were detected. Bartonella prevalence ranged between 0% and 87.5% by animal species, with 74.3% in the predominant Neotoma micropus and 78% in the second most abundant N. albigula. The mean duration of Bartonella bacteremia in mark-recaptured N. micropus and N. albigula was 4.4 months, ranging from <1 to 18 months, and differed among Bartonella genogroups. Phylogenetic analysis of the Bartonella citrate synthase gene (gltA) revealed 9 genogroups and 13 subgroups. Seven genogroups clustered with known or previously reported Bartonella species and strains while two were distant enough to represent new Bartonella species. We report, for the first time, the detection of Bartonella alsatica in North America in Sylvilagus audubonii and expand the known host range of Bartonella washoensis to include Otospermophilus variegatus. Interpretation and Conclusion: This work broadens our knowledge of the hosts and geographic range of bacterial pathogens that could guide future surveillance efforts and improves our understanding of the dynamics of Bartonella infection in wild small mammals.