Mechanical transmission of human protozoan parasites by insects

Evaluating the role of synanthropic filth flies in the transmission of zoonotic parasites: field and laboratory evidence from different animal rearing sites in upper Egypt with focus on Cryptosporidium spp

BACKGROUND

Synanthropic filth flies thrive in human and animal habitats, posing health risks through the transmission of infectious agents. They breed on organic waste, including animal feces, making them carriers of various pathogens. In Egypt, where livestock farming is common and poor sanitation, these flies may contribute to zoonotic disease transmission. The current study investigates parasitic infections in filth flies from three livestock farms in Assiut Governorate, Upper Egypt, highlighting their role as vectors for zoonotic infections, particularly Cryptosporidium, via morphological and molecular tools.

METHODS

A total of 12,749 flies were collected from the study sites via sweep nets. After taxonomic identification, the flies were examined microscopically for parasites using various concentration and staining techniques. Positive samples were further confirmed for infections, particularly for Cryptosporidium parasites, via nested PCR and sequence analysis targeting the COWP and SSU rRNA genes.

RESULTS

This study revealed the presence of several fly species from seven dipteran families, particularly the family Muscidae, primarily Musca domestica, which presented a high parasite infestation rate of 96.6%. This study revealed a high prevalence of various protozoans and helminths in the collected flies. Cryptosporidium was the most prevalent parasite (64.4-100%), infecting all fly species. Entamoeba and Balantidium were also significant, especially in M. domestica (22.6-90.1%, 8.9-100%), Fannia canicularis (10.5-74.4%, 44.2-88.2%), and Borborillus vitripennis (11.1-50%, 37.2-91.4%). Giardia, Trichuris, and Trichostrongylidae had low to moderate prevalence in multiple fly species. Mites are commonly detected on fly exoskeletons, with high infestation rates observed in Musca domestica (77-100%) and Physiphora alceae (66.7-100%). The present study also reported sporadic infections with Trichomonas, Toxocara vitulorum, and pseudoscorpions, along with notable midge larval infestations (52.1%), mainly at site B. Parasitic infections were highest in autumn and spring, with the lowest rates in winter. Molecular identification confirmed the presence of the zoonotic species Cryptosporidium parvum and Cladotanytarsus gedanicus.

CONCLUSION

This study revealed that zoonotic parasites exist in flies and pose potential risks when they are found near humans. Cryptosporidium parvum is the prevalent parasite causing diarrhea outbreaks in animals. This is the first genetic evidence of Cladotanytarsus gedanicus midge from Upper Egypt.

Identification and distribution of some medico-veterinary important pathogens in muscid flies in two geographical regions of Türkiye

Some dipteran flies play an important role in the transmission of pathogens such as viruses, bacteria, fungi, protozoan and metazoan parasites in humans and other animals. Despite this importance, knowledge of the prevalence and molecular characteristics of some pathogens in flies is limited, and no data are available for Türkiye. In this study, we investigated the possible vector role of muscid fly species for the transmission of Enterocytozoon bieneusi Desportes (Chytridiopsida: Enterocytozoonidae), Encephalitozoon spp., Coxiella burnetii Derrick (Legionellales: Coxiellaceae) and Thelazia spp. using polymerase chain reaction (PCR) and sequence analysis. The flies were trapped in different animal-related places and surroundings from two different geographical regions of Türkiye including Central Anatolia and Middle Black Sea. According to the morphological keys, 850 (85%), 141 (14.1%) and 6 (0.6%) of the total of 1000 fly specimens identified as Musca domestica Linnaeus (Diptera: Muscidae), Stomoxys calcitrans Linnaeus (Diptera: Muscidae) and Musca autumnalis De Geer (Diptera: Muscidae), respectively. The other species including Haematobia irritans Linnaeus (Diptera: Muscidae), Muscina stabulans Fallén (Diptera: Muscidae) and Hydrotaea ignava Harris (Diptera: Muscidae) were each represented by a single specimen. Screening of the pathogens identified E. bieneusi only in M. domestica with a prevalence of 2.4%. Sequence analyses identified three known genotypes, Type IV, BEB6 and BEB8, and one novel genotype named AEUEb of E. bieneusi in M. domestica. Coxiella burnetii was detected in M. domestica and S. calcitrans with prevalences of 2.9% and 2.8%, respectively. The one specimen of H. ignava was also positive for C. burnetii. Encephalitozoon spp. and Thelazia spp. were not found in the examined specimens. Our results contribute to the current knowledge on the vector potential of muscid flies and their possible role in the transmission dynamics of certain pathogens, especially in regions where diseases are prevalent and affect public and animal health.

Risk assessment of the mechanical spread of bacterial pathogens due to Lasius neglectus ants infesting a tertiary hospital

INTRODUCTION

Mechanical spread of microbial pathogens has been investigated in cockroaches, but less well in ants. Considerably less information is available for ants. An investigation into ant-borne mechanical pathogen transmission was triggered by an infestation of a tertiary care hospital with Lasius neglectus ants.

METHODS

The L. neglectus infestation of the orthopaedic surgery department, the ear-nose-throat clinic and the eye clinic as well as of outdoor areas was monitored and correlated with seasonal and weather influences. Microbial colonization on the ants' exoskeleton as well as in homogenates of complete insects and decolonization dynamics of artificial Staphylococcus aureus colonization on the exoskeleton was assessed.

RESULTS

In a low-level infestation setting, L. neglectus activity showed seasonal variations and was positively correlated with temperature (r = 0.7515; P=0.0368) but not with precipitation (r = 0.4699, P=0.2431). Colonization with environmental commensals dominated, while exoskeleton colonization with bacteria with potential aetiological relevance for nosocomial infections was higher for ants from the inpatient setting (6%) than from outdoor areas (0%). Artificial colonization of the exoskeleton with S. aureus vanished to values statistically indistinguishable from baseline within 72 h.

CONCLUSIONS

Low colonization rates with aetiologically relevant bacteria and rapid spontaneous decolonization in the case of contamination make ant-borne transmissions to patients unlikely.

Blowflies (Diptera: Calliphoridae) as potential mechanical vectors of the protozoan cyst and helminthic eggs in Kashmir Himalaya, India

Blowflies (Diptera: Calliphoridae) are an important group of non-biting flies that are potential mechanical vectors of protozoan and helminthic pathogens. The present study was carried out to isolate and identify protozoan cysts and helminthic eggs transmitted by blowflies. Surveys were carried out at six different sites, viz., butcher shops, fish markets, garbage piles, water bodies, and open vegetation in the Kashmir Himalaya. The flies were collected with the help of a sweeping net and using day-old beef liver as bait from March 2021 to February 2023. A total of 968 blowflies were collected, out of which 83 were found carrying at least one protozoan cyst and helminthic egg with six identified species of parasites. Garbage piles were recorded with the highest number of positive cases (10.81%), while human habitation had the highest transmission rate (3.3%). Chrysomya megacephala (Fabricius) was reported to have the highest number of parasitic cysts and ova (one protozoan cyst and three helminthic eggs), while Ascaris lumbricoides and Entamoeba coli were found to be the most abundant parasites reported from the surface of these flies. The number of parasites isolated from the surface of the blowflies was statistically significant (F = 9.073, df = 1, and p = 0.014), indicating a positive association between the number of parasites isolated from blowflies and the collection sites.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-024-01663-5.

Molecular detection and genotyping of Dientamoeba fragilis and Blastocystis sp. in housefly Musca domestica (Diptera: Muscidae): first report for Dientamoeba fragilis

Dientamoeba fragilis and Blastocystis sp. are single-celled protozoan parasites of humans and animals. Although they are found in the intestines of healthy hosts, the pathogenicity of them is still unclear. To date, there is no report on D. fragilis and only two studies (without subtyping) on the occurrence of Blastocystis sp. in Musca domestica. In this study, fly samples were collected from livestock farms and their surroundings in the Kirsehir province (Central Anatolia Region) of Türkiye from May to August 2023. A total of 150 microscopically identified M. domestica samples were analyzed for the detection of D. fragilis and Blastocystis sp. molecularly. The overall prevalence of Blastocystis sp. and D. fragilis in M. domestica was determined to be 3.3% (5/150) and 8.0% (12/150), respectively. The SSU rRNA gene sequences of the isolates indicated genotype 1 of D. fragilis. Eleven isolates were identical and represented a single isolate (KAU-Dfrag1). BLAST analysis of KAU-Dfrag1 indicated identity with the isolates reported from humans, cattle, sheep, and budgerigars. The other isolate (KAU-Dfrag2) was polymorphic at two nucleotides from KAU-Dfrag1 and three nucleotides from known genotypes from GenBank and represented a variant of genotype 1. The Blastocystis sp. isolates were found to be identical and represent a single genotype (KAU-Blast1). BLAST analysis revealed that the KAU-Blast1 genotype belonged to the potentially zoonotic subtype 5 (ST5) and exhibited the highest genetic identity (ranging from 99.4 to 99.6%) with pigs, cattle, and sheep from different countries. Our study provides the first data on the molecular prevalence, epidemiology, and genotypic characterization of D. fragilis and Blastocystis sp. in M. domestica.

Cockroaches as carriers of human medically important parasites

Cockroaches have been identified as mechanical carriers of pathogens capable of infesting humans. The primary objective of this research was to detect and separate medically significant parasites found within the collected cockroaches. A total of 185 cockroaches were captured. In the laboratory, cockroaches underwent a series of steps. Initially, they were washed in a saturated salt solution and rinsed with 70% alcohol, dried, and subsequently dissected to examine endoparasites. In this study, a transport rate of 29.729% was documented, and four types of helminths were identified, which included Ascaris lumbricoides (47.27%), Enterobius vermicularis (30.91%), Trichuris spp. (7.27%), and Hymenolepis nana (14.55%). The parasites were more frequently found on the external surface of cockroaches (38/69.09%), compared to the internal surface (17/30.91%). Cockroaches captured in toilets were found to carry a higher percentage of parasites (31/16.75%) compared to those from kitchens (11/5.94%) and houses (13/7.02%). These findings suggest that cockroaches can serve as carriers for intestinal parasites and potentially act as mechanical agents in the dissemination of these parasites.

Intestinal pathogens detected in cockroach species within different food-related environment in Pudong, China

Cockroaches are considered mechanical transmitters of infectious diseases, posing a threat to human health. This study assessed the potential of cockroaches in food-related environments to mechanically transmit intestinal pathogens. Cockroaches captured with traps were placed together into a low temperature refrigerator at - 80° for 2 h. Standard taxonomic keys and Fluorescent quantitative PCR techniques were applied for species identification and digestive tract etiological examination. A total of 360 cockroach traps were placed, with a positive rate of 20.8%, and 266 cockroaches were captured. In general, compared with other places and areas, the degree of infestation of cockroaches was more serious in catering places and kitchens. Blattella germanica were most found in catering places (40.2%), followed by Periplaneta fuliginosa in schools (22.2%). According to the life stage, among the 128 cockroach samples, 23 were positive for nymphs and 13 were positive for adults. There were statistically significant differences in the intestinal pathogen detection rates between nymphs and adults (P < 0.05). A total of eight intestinal pathogens were detected, and enterovirus infections were the main ones, with sapovirus being the most detected in Blattella germanica or nymph. Shiga toxin-producing Escherichia coli (STEC) was the most frequently isolated bacterium. Blastocystis hominis had the highest isolation rate. In contrast, 12 diarrhoeal disease pathogens were isolated, and the viruses and bacteria with the highest frequencies were norovirus and E. coli, respectively; no parasites were found. Blattella germanica and Periplaneta fuliginosa in food-related environments can act as potential vectors for the spread of intestinal pathogens and may pose a significant threat to public health.

Performance evaluation of protocols for Taenia saginata and Ascaris suum egg recovery from the house fly's gastrointestinal tract and exoskeleton

BACKGROUND

The synanthropic house fly (Musca domestica) can potentially contribute to the mechanical spread of eggs of Taenia and Ascaris spp. in the environment and between hosts. However, the absence of validated protocols to recover eggs hampers an in-depth analysis of the house fly's role in parasite egg transmission.

METHODS

The gastrointestinal tract and exoskeleton of euthanized house flies were spiked with Taenia saginata eggs. The performance of several recovery protocols, in terms of both the recovery rate and ease-of-use, was (microscopically) evaluated and compared. These protocols employed steps such as washing, maceration, filtration, flotation and both passive and centrifugal sedimentation. The final validated protocols were subsequently evaluated for the recovery of Ascaris suum eggs.

RESULTS

The final protocol validated for the recovery of T. saginata eggs from the house fly's gastrointestinal tract involved homogenization in phosphate-buffered saline and centrifugation at 2000 g for 2 min, yielding a recovery rate of 79.7%. This protocol required 6.5 min to perform (which included 1.5 min of hands-on time) and removed large debris particles that could hinder the differentiation of eggs from debris. Similarly, the final protocol validated for the recovery of T. saginata eggs from the fly's exoskeleton involved washing by vortexing for 2 min in Tween 80 (0.05%), 15 min of passive sedimentation and centrifugation at 2000 g for 2 min, yielding a recovery rate of 77.4%. This protocol required 20.5 min to perform (which included 3.5 min of hands-on time) and successfully removed debris. The same protocols yielded recovery rates of 74.2% and 91.5% for the recovery of A. suum eggs from the fly's gastrointestinal tract and exoskeleton, respectively.

CONCLUSIONS

Effective, simple and easy-to-use protocols were developed and validated for the recovery of T. saginata and A. suum eggs from the house fly's gastrointestinal tract and exoskeleton. These protocols can be applied to investigate the importance of flies as parasite egg transmitters in laboratory and field settings.

Bat-associated microbes: Opportunities and perils, an overview

The potential biotechnological uses of bat-associated bacteria are discussed briefly, indicating avenues for biotechnological applications of bat-associated microbes. The uniqueness of bats in terms of their lifestyle, genomes and molecular immunology may predispose bats to act as disease reservoirs. Molecular phylogenetic analysis has shown several instances of bats harbouring the ancestral lineages of bacterial (Bartonella), protozoal (Plasmodium, Trypanosoma cruzi) and viral (SARS-CoV2) pathogens infecting humans. Along with the transmission of viruses from bats, we also discuss the potential roles of bat-associated bacteria, fungi, and protozoan parasites in emerging diseases. Current evidence suggests that environmental changes and interactions between wildlife, livestock, and humans contribute to the spill-over of infectious agents from bats to other hosts. Domestic animals including livestock may act as intermediate amplifying hosts for bat-origin pathogens to transmit to humans. An increasing number of studies investigating bat pathogen diversity and infection dynamics have been published. However, whether or how these infectious agents are transmitted both within bat populations and to other hosts, including humans, often remains unknown. Metagenomic approaches are uncovering the dynamics and distribution of potential pathogens in bat microbiomes, which might improve the understanding of disease emergence and transmission. Here, we summarize the current knowledge on bat zoonoses of public health concern and flag the gaps in the knowledge to enable further research and allocation of resources for tackling future outbreaks.

Control study of Musca domestica (Diptera, Muscidae) in Misan Province

Background

Houseflies are the most common type of Diptera, specifically Muscidae, worldwide, representing more than 90% of all species. This family has over 170 genera and 4200 species, but a few are of medical significance. This study aimed to estimate and assessing the measures to control and prevent grow-up inside houses and flying of the housefly ( Musca domestica Linnaeus, 1758) in Misan.

Methods

The study occurred over 12 months, from December 2020 to December 2021. Using plastic containers, Musca domestica were collected from all potential breeding sites in the study region (inside and around houses). Sticky oil paper and traps were used to collect the insects. The collected insects were transferred to sealed plastic containers and then to the laboratory of the Department of Microbiology.Out of 200 randomly selected houses, 150 (75%) contained insects. Light traps and sticky oil papers were the most effective control measures, with 26.7% and 25.9% of the Musca domestica collected from these methods, respectively. The ratio of male (233) to female (456) Musca was 1:2, with a significant difference between the frequencies (P<0.05). A large population of houseflies was collected during the hot season (501, 72.7%), whereas fewer Musca were collected during the cold months (188, 27.3%), with a strongly significant difference (P<0.05). The percentage of HI was 54.4%, the CI was 21.9%, and the BI was 79.9%. The overall larval densities (LD) were at a medium level.

Conclusions

Misan has a high density of Musca domestica, with females being more prominent than males. Hot climate, humid sites, and dirty places are responsible for the breeding of houseflies. The overall larval density was medium. Therefore, the risk of transmitting infectious diseases by houseflies is high within the boundaries of Misan province, and effective control parameters should include measures like light traps and sticky oil.

Sarcosaprophagous Muscid Fly (Diptera: Muscidae) Assemblages Along an Anthropized Gradient in the Humid Chaco Ecoregion, Chaco Province, Argentina

Deforestation, agriculture, farmyard animal husbandry, and urbanization are known to be the main causes of biodiversity loss and habitat fragmentation. The present study evaluated the role of anthropization in modulating Muscidae (Diptera) assemblages in the Humid Chaco ecoregion of Argentina, by testing the biotic homogenization and intermediate disturbance hypotheses. The study focused on natural, rural, and urban habitats in San Lorenzo Department, Chaco Province, where sarcosaprophagous muscid flies were surveyed. A total of 1,343 muscid flies were captured and identified to 7 genera and 24 species and morphospecies. We observed the effect of anthropization on the structuring of the assemblages and the presence of exotic species associated with human activity resulting from biotic homogenization. The highest abundance was recorded in the urban habitat, while the highest species richness and diversity (Shannon-Wienner and Hill's numbers) were found in the rural habitat, supporting the intermediate disturbance hypothesis. Several species are classified as indicators of habitat as well as according to their index of synanthropy. Our results provide valuable information about the use of sarcosaprophagous muscids as indicators of disturbance of natural habitats and about possible health risks related to this family of Calyptratae flies previously unsurveyed in northeastern Argentina. This information could be used in the ecological, agronomy, sanitary, and forensic fields.

Foodborne Diseases in the Edible Insect Industry in Europe-New Challenges and Old Problems

Insects play a key role in European agroecosystems. Insects provide important ecosystem services and make a significant contribution to the food chain, sustainable agriculture, the farm-to-fork (F2F) strategy, and the European Green Deal. Edible insects are regarded as a sustainable alternative to livestock, but their microbiological safety for consumers has not yet been fully clarified. The aim of this article is to describe the role of edible insects in the F2F approach, to discuss the latest veterinary guidelines concerning consumption of insect-based foods, and to analyze the biological, chemical, and physical hazards associated with edible insect farming and processing. Five groups of biological risk factors, ten groups of chemical risk factors, and thirteen groups of physical risks factors have been identified and divided into sub-groups. The presented risk maps can facilitate identification of potential threats, such as foodborne pathogens in various insect species and insect-based foods. Ensuring safety of insect-based foods, including effective control of foodborne diseases, will be a significant milestone on the path to maintaining a sustainable food chain in line with the F2F strategy and EU policies. Edible insects constitute a new category of farmed animals and a novel link in the food chain, but their production poses the same problems and challenges that are encountered in conventional livestock rearing and meat production.

The global prevalence of parasites in non-biting flies as vectors: a systematic review and meta-analysis

BACKGROUND

Non-biting flies such as the house fly (Musca domestica), the Australian sheep blowfly (Lucilia cuprina) and the oriental latrine fly (Chrysomya megacephala) may carry many parasites. In the present study, we performed a systematic overview of the different species of parasites carried by non-biting flies, as well as of isolation methods, different geographical distribution, seasonality and risk assessment.

METHODS

A meta-analysis was carried out with the aim to review the global prevalence of parasite transmission in non-biting flies. A total sample size of 28,718 non-biting flies reported in studies worldwide satisfied the predetermined selection criteria and was included in the quantitative analysis.

RESULTS

The global prevalence of parasites in non-biting flies was 42.5% (95% confidence interval [CI] 31.9-53.2%; n = 15,888/28,718), with the highest prevalence found for non-biting flies in Africa (58.3%; 95% CI 47.4-69.3%; n = 9144/13,366). A total of 43% (95% CI 32.1-54.4%; n = 7234/15,282) of house flies (M. domestica), the fly species considered to be the most closely associated with humans and animals, were found with parasites. The prevalence of parasites in the intestine of non-biting flies was 37.1% (95% CI 22.7-51.5%; n = 1045/3817), which was significantly higher than the prevalence of parasites isolated from the body surface (35.1%; 95% CI 20.8-49.4%; n = 1199/3649; P < 0.01). Of the 27 reported parasites, a total of 20 known zoonotic parasites were identified, with an infection rate of 38.1% (95% CI 28.2-48.0%; n = 13,572/28,494).

CONCLUSIONS

This study provides a theoretical basis for the public health and ecological significance of parasites transmitted by non-biting flies.

Lack of Detection of Toxoplasma gondii in Pipistrellus spp. Bats from Densely Cat-Populated Areas of NE Spain

Toxoplasma gondii infection in healthy animals is often asymptomatic. However, some species with little history of contact with the parasite, such as marsupials and New World primates, present high mortality rates after infection. Despite its potential conservation concern, T. gondii infection in insectivorous bats has received little attention, and its impact on bat populations' health is unknown. To assess the putative role of insectivorous bats in the cycle of T. gondii, samples of three species of bats (Pipistrellus pipistrellus, P. pygmaeus and P. kuhlii) collected between 2019 and 2021 in NE Spain were tested for the presence of the parasite using a qPCR. All tissues resulted negative (0.0% prevalence with 95% CI: [0.0-2.6]) for the presence of T. gondii. Unlike previous studies on insectivorous bats from Europe, Asia and America, the present study suggests that Pipistrellus spp. bats do not play a significant role in the epidemiology of T. gondii in NE Spain. Further studies are encouraged to elucidate both the epidemiology of T. gondii and its potential impact on the health of microchiropteran species in Europe.

Gut Parasites of medical importance harboured by Musca domestica in Calabar, Nigeria

Introduction

Housefly (Musca domestica), because of its body structure, filthy and feeding habits, is reported to be capable of carrying a variety of microbes, including potential pathogens, over its body appendages.

Aims

This study aimed to investigate M. domestica in Calabar for pathogenic gut parasites, determine its role in parasitic diseases transmission, make appropriate recommendations toward its management and effective control of the associated parasitic diseases, and hence promote the society health status.

Settings and Design

This was a cross-sectional study.

Materials and Methods

A total of 300 M. domestica specimens (150 each from sanitary and insanitary areas, pooled in batches of five flies per pool) were used for the study. The parasites were detected from the spun deposits of fly body surface wash and gut contents using direct microscopy and formol-ether technique.

Statistical Analysis Used

Data were analyzed using Statistical Package for the Social Sciences (SPSS), version 21.0, and Chi-square test at a significant level of P < 0.05.

Results

Overall frequency of parasites detection was 46.7%, with helminths and protozoa showing similar frequency, 23.3% each. External body surface of flies recorded a statistically significant higher parasites frequency 76.7% than their gut contents 16.7% (P = 0.000). A statistically significant higher parasite detection rate was observed in the insanitary (63.3%) than in sanitary areas (30.0%) (P = 0.0114). The parasites detected in this study were Entamoeba histolytica/dispar 39.9%, hookworm (21.4%), Ascaris lumbricoides (17.9%), Trichuris trichiura (14.3%), and Giardia intestinalis (7.2%).

Conclusion

This study has confirmed M. domestica in Calabar as a mechanical carrier of potential pathogenic gut parasites, especially in the insanitary areas, with E. histolytica/dispar being the most frequently encountered. Effective control of flies' population in the human and animal habitats and increased public awareness on their health hazards are recommended.

Antimicrobial peptide expression in the cockroach gut during enterobacterial infection is specific and influenced by type III secretion

Omnivorous synanthropic cockroaches, such as the German cockroach (Blattella germanica), are reservoirs and vectors of enteric bacterial pathogens. A lifestyle conducive to frequent encounters with high loads of diverse bacteria may have led to the evolution of unique innate immune systems in these insects. The innate immune response of insects relies largely on generalized mechanisms to sense and eliminate foreign microbes. However, analyses of the genomes of common synanthropic cockroaches previously revealed a repertoire of pathogen associated molecular pattern (PAMP) receptors and antimicrobial peptides (AMPs) that is significantly expanded relative to most holometabolous insect models and vectors, supporting the intriguing possibility that cockroaches may encode enhanced recognition within their immune system and may possess an enhanced capacity to fine tune innate immune responses. Investigating how cockroaches respond to infection with enterobacteria provides the opportunity to expand our fundamental knowledge of the regulation of insect innate immunity in a context that is biologically and medically relevant. German cockroaches can harbor both Salmonella enterica serovar Typhimurium and Escherichia coli in their gut without experiencing pathogenesis. The former colonizes the gut and replicates while the latter persists only transiently. We hypothesized that differences in the innate immune response may contribute to or result from the difference in infection dynamics between the two enterobacteria. To test this hypothesis, we used qRT-PCR to analyze expression of five genes encoding representative AMPs (Attacins, Blattellicin, Defensins) in the gut of German cockroaches 1 and 24 h after ingestion of live or heat-killed enterobacteria. We found that robust AMP expression was induced in response to ingestion of a live wild-type strain of S. Typhimurium, but not in response to live E. coli, heat-killed S. Typhimurium, or a live mutant strain of S. Typhimurium lacking type III secretion systems. These results indicate that the cockroach immune system does not respond to stimulation with high levels of ingested bacterial PAMPs such as peptidoglycan. Rather, AMP expression in the gut appears to be induced by active bacterial colonization involving type III secretion. We speculate that this form of regulation may have evolved to prevent over activation of the immune system from frequent ingestion of innocuous, non-colonizing, or non-viable bacteria. While additional work is needed to delineate the molecular mechanisms underlying our observations, our findings provide significant novel insight into the immunological adaptation of cockroaches to life in septic environments as well as the factors that regulate bacterial pathogen transmission by these insects.

Molecular Evidence of Emerged Pulmonary Lophomoniasis due to Lophomonas blattarum among Hospitalized Patients in Southwestern Iran: A National Registry-Based Study

Objectives

Lophomonas protozoan is an emerging pathogen transmitted through arthropods such as cockroaches. Lophomoniasis is still a mysterious disease with many unknown epidemiological aspects. The current study aimed to determine the prevalence of lophomoniasis among patients who were hospitalized in Hajar Hospital, Shahrekord, southwestern Iran, using a conventional PCR technique.

Methods

In this retrospective study, 132 frozen bronchoalveolar lavage fluid (BALF) specimens from patients with respiratory disorders hospitalized in Hajar Hospital, Shahrekord district, southwestern Iran, were analyzed during 2020-2021. Samples are referred to the Iranian National Registry Center for Lophomoniasis (INRCL), Mazandaran Province, Northern Iran, for detecting Lophomonas spp. infection by a conventionally small subunit ribosomal RNA (SSU rRNA) PCR test.

Results

A total of 132 frozen BALF specimens were examined, 36 (27.3%) tested Lophomonas spp. positive using the conventional PCR technique. Also, based on sequencing data and blast analysis, the presence of L. blattarum species was confirmed. The average age of Lophomonas spp.‐ positive patients was 67.02 ± 15.14 years. Out of the 36 positive subjects, 63.9% were male and 36.1% female. Male and Lophomonas infection had a significant correlation (p=0.001). Our findings revealed that L. blattarum infected nonsmokers more than smokers (p=0.001). The most common underlying disease was also bronchitis

Conclusion

Our results showed, for the first time, that pulmonary lophomoniasis caused by L. blattarum is a common and emerging disease in the study area, southwestern Iran. Furthermore, our findings support the use of the PCR test to detect Lophomonas infection in archived frozen clinical samples.

Prevalence and diversity of intestinal parasites in household and temple pigeons ( Columba livia ) in central Nepal

Background

Intestinal infection, caused by various protozoans and helminths, represents one of the significant health concerns in pigeons around the world.

Objectives

The present study aimed to determine the diversity and prevalence of the intestinal parasites in pigeons found in Ratnanagar Municipality, Chitwan, in central Nepal.

Methods

The fresh faecal samples (n = 155) were non‐invasively collected from different households and temples pigeons The individual samples were immediately preserved in the 2.5% potassium dichromate solution and transported to the research laboratory. Following direct wet mount and concentration methods, the samples were observed under a compound microscope.

Results

The results showed 87.1% prevalence rate with 16 parasite species that included 8 protozoan and 8 helminth faunae. The faecal samples of temple pigeons contained a higher prevalence rate with higher parasitic richness (95.6%; 16 species) than household pigeons (75.4%; 12 species). Mixed infection up to four different species was recorded in both types of sampling populations.

Conclusions

Pigeons harbour a greater prevalence and wider diversity of intestinal parasites and the parasitism varies based on the habitats. Proper management and effective deworming practices are recommended to control intestinal parasitic infection in these avian hosts.

A Systematic Review of Zoonotic Enteric Parasites Carried by Flies, Cockroaches, and Dung Beetles

Filth flies, cockroaches, and dung beetles have been close neighbors with humans and animals throughout our joint histories. However, these insects can also serve as vectors for many zoonotic enteric parasites (ZEPs). Zoonoses by ZEPs remain a paramount public health threat due to our close contact with animals, combined with poor water, sanitation, and hygiene access, services, and behaviors in many global regions. Our objective in this systematic review was to determine which ZEPs have been documented in these vectors, to identify risk factors associated with their transmission, and to provide effectual One Health recommendations for curbing their spread. Using PRISMA guidelines, a total of 85 articles published from 1926 to 2021 were reviewed and included in this study. Qualitative analysis revealed that the most common parasites associated with these insects included, but were not limited to: Ascaris spp., Trichuris spp., Entamoeba spp., and Cryptosporidium spp. Additionally, prominent risk factors discovered in the review, such as poor household and community WASH services, unsafe food handling, and exposure to domestic animals and wildlife, significantly increase parasitic transmission and zoonoses. The risk of insect vector transmission in our shared environments makes it critically important to implement a One Health approach in reducing ZEP transmission.

New insight into the relationship between Salmonella Typhimurium and the German cockroach suggests active mechanisms of vector-borne transmission

Diarrheal diseases are among the most common illnesses in the world and the bacterium Salmonella enterica serovar Typhimurium is a leading cause of morbidity and mortality from diarrhea globally. The German cockroach (Blattella germanica) frequently harbors and has been linked to human outbreaks of Salmonella, but the mechanisms of vector-borne transmission are not fully clear. Transmission of S. Typhimurium by cockroaches has been previously described as mechanical. Mechanical transmission is a wholly passive process that involves physical transfer of a pathogen from one location or host to another but lacks bacterial replication in the vector and active bacterial processes that promote vector colonization or transmission. Towards the goal of obtaining novel insight into the mechanisms of S. Typhimurium transmission by cockroaches, here we orally provisioned wild type and mutant strains of the bacteria to adult B. germanica and examined several aspects of colonization and shedding. Our results provide evidence of three previously unappreciated phenomena with significant implications. First, we demonstrate that S. Typhimurium undergoes replication at multiple phases during colonization of the cockroach gut. Second, we show the formation of biofilm-like aggregates by S. Typhimurium in the cockroach foregut. Lastly, we identify two mutant strains of S. Typhimurium that are deficient in colonization and shedding relative to isogenic controls, implicating type III secretion and the formation of fimbriae as two processes that are necessary for interaction with the cockroach vector. Together, our data indicate that transmission of S. Typhimurium by cockroaches is not solely mechanical but may resemble biological transmission by other insect vectors that intake human pathogenic bacteria from infected hosts and are subsequently colonized, enabling active dissemination. Thus, these findings suggest that cockroaches and their control may be more important for infection prevention than is currently appreciated. Additional studies to better understand the cycle and biological mechanisms of vector-borne transmission are warranted.

Environmental and human health impacts of cruise tourism: A review

The intensive growth of cruise tourism worldwide during recent decades is leading to growing concerns over the sector's global environmental and health impacts. This review combines for the first time various sources of information to estimate the magnitude of the cruise industry's environmental and public health footprints. This research shows that cruising, despite technical advances and some surveillance programmes, remains a major source of air, water (fresh and marine) and land pollution affecting fragile habitats, areas and species, and a potential source of physical and mental human health risks. Health risks impact both the people on board (crew and passengers) and on land (workers of shipyards where cruise ships are dismantled and citizens inhabiting cities with cruise ports and shipyards). In this context, we argue that the cruise industry should be held accountable with more monitoring and regulation to prevent or minimize the growing negative environmental and human health impacts.

Flesh fly (Diptera: Sarcophagidae): male terminalia, diversity and expanded geographical distribution from India

Despite its veterinary, medical and forensic importance, the biodiversity of sarcophagid flies (Diptera: Sarcophagidae) has remained poorly investigated in India. We have performed a survey of Sarcophagidae species in connection with a study conducted on Diptera, which exposed the flesh fly diversity in and around the campus of the University of Calicut, Kerala, India. The survey was conducted using traps baited with decomposing fish and chicken liver and by the sweeping method. Eleven species were collected, including four species recorded from this state for the first time, one of which is new to the Indian mainland and the second record after Sundarbans Biosphere Reserve. Male terminalia of Sinonipponia bengalensis, Parasarcophaga choudhuryi, Boettcherisca karnyi, and Boettcherisca nathani are illustrated. This result expands the knowledge on the geographical distribution and habitat occupancy of sarcophagid species as well as their forensic relevance and provides a background for future systematic investigations.

Drivers of insect consumption across human populations

Discussions regarding entomophagy in humans have been typically led by entomologists. While anthropologists devote much time to understanding diverse human subsistence practices, historical and cultural variation in insect consumption remains largely unexplained. This review explores the relation between variable ecologies, subsistence strategies, and social norms on insect consumption patterns across past and contemporary human populations. Ecological factors, such as the nutritional contribution of edible insects relative to those of other foraged or farmed resources available, may help explain variation in their consumption. Additionally, our evolved social learning strategies may help propagate social norms that prohibit or prioritize the consumption of some or all edible insects, independent of their profitability. By adopting a behavioral ecological and cultural evolutionary approach, this review aims to resolve current debates on insect consumption and provide directions for future research.

Laboratory and Field Evaluations of Food-Based Attractants for Monitoring German Cockroaches

Sticky traps are standard tools for monitoring German cockroaches (Blattella germanica L.); however, because they lack an attractant, their ability to catch cockroaches is by chance and largely dependent upon the location of placement and length of time they are left in place. Currently, highly effective and economical cockroach attractants are not available. Food-based attractants have the potential to be employed in sticky traps and enhance their effectiveness on trapping German cockroaches. We conducted laboratory and field experiments to evaluate the effectiveness of novel food-based attractants. Laboratory results showed that sticky traps containing the following attractants: apple oil, blueberry oil, orange oil, or their combination, fish oil, peanut butter, Roach lure tablet, and bacon extract had significantly higher trap catch compared to those traps that do not contain an attractant. Apple plus blueberry oil mixture and Roach lure tablet enhanced the trap catch by ≥ 103%, and bacon extract enhanced the trap catch by 92% in the field assays. Apple plus blueberry oil mixture and Roach lure tablet were the most promising attractants based on laboratory and field experiments. Apple plus blueberry oil mixture aged for 2 wk was as attractive to German cockroaches as fresh mixture.

Zoonotic and Reverse Zoonotic Transmissibility of SARS-CoV-2

The Coronavirus Disease 2019 (COVID-19) is the first known pandemic caused by a coronavirus. Its causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), appears to be capable of infecting different mammalian species. Recent detections of this virus in pet, zoo, wild, and farm animals have compelled inquiry regarding the zoonotic (animal-to-human) and reverse zoonotic (human-to-animal) transmissibility of SARS-CoV-2 with the potential of COVID-19 pandemic evolving into a panzootic.

It is important to monitor the global spread of disease and to assess the significance of genomic changes to support prevention and control efforts during a pandemic. An understanding of the SARS-CoV-2 epidemiology provides opportunities to prevent the risk of repeated re-infection of humans and requires a robust One Health-based investigation. This review paper describes the known properties and the existing gaps in scientific knowledge about the zoonotic and reverse zoonotic transmissibility of the novel virus SARS-CoV-2 and the COVID-19 disease it causes.

Edible Insects and Toxoplasma gondii: Is It Something We Need To Be Concerned About?

ABSTRACT

Novel foods, such as edible insects and food products on the basis of insects, could play an important role in both human and animal nutrition in the future. The identification of dangers associated with insect consumption is fundamental to guarantee consumer safety and adequate regulatory guidelines for operators of the food sector. Although former studies have focused on the microbiological contamination of fresh or processed edible insects, so far little information is available about the occurrence of foodborne parasites, such as Toxoplasma gondii, whose life cycles make them candidates for potential insect breeding substrate contamination. Hence, we investigated the presence of contaminating T. gondii in farmed edible insects to rule out this further hazard for consumers. Four species of insects most commonly used as food for human consumption were analyzed: mealworm; African migratory locust, house cricket, and silkworm. Samples included live specimens but also minimally (dehydrated) and highly processed edible insects. Traces of T. gondii DNA were detected in samples of dehydrated mealworm. These results highlight the need for implementing good farming and processing practices with particular care paid to safe storage and handling of feed and substrates used for edible insects to reduce the chance of T. gondii entering the human food chain.

HIGHLIGHTS

Occurrence of Toxoplasma gondii on Raw Leafy Vegetables in Gaza, Palestine

ABSTRACT

Toxoplasma gondii, a ubiquitous obligate intracellular parasite that can infect homeothermic animals, is one of the main pathogens causing foodborne diseases worldwide. In Gaza, Palestine, leafy vegetables are frequently eaten raw. The present study was carried out to investigate the occurrence of T. gondii oocyst in local leafy vegetables. Fifty samples each of six species of leafy plants sold in open-air markets, in supermarkets, and by retail sellers were randomly collected from March to August 2019, for a total of 300 samples. The samples were examined by light microscopy after flotation in Sheather's sucrose solution and by PCR assay of the pelleted samples. All suspect T. gondii oocysts were confirmed with a PCR assay. With the PCR assay of the pelleted samples, only 19 (6.33%) of the 300 samples were positive for T. gondii, whereas with the Sheather's flotation method, 35 (11.66%) of the 300 samples were positive. With the PCR assay, among the six plant types mint had the highest T. gondii prevalence (10.00% of samples) followed by watercress and dill (both 8.00%), parsley (6.00%), thyme (4.00%), and lettuce (2.00%). Even though the relative prevalence of T. gondii in the contaminated plant species was similar with both the PCR and Sheather's flotation methods, the actual prevalences were different. With Sheather's flotation, T. gondii prevalence was highest in mint (18.00% of samples) followed by watercress (14.00%), dill (13.00%), parsley (10.00%), thyme (10.00%), and lettuce (6.00%). The relationship between T. gondii contamination and the time of year the samples were collected was also significant. The highest prevalence recorded was in July followed by June and August. These findings indicate that leafy vegetables, particularly mint, can be contaminated with T. gondii and are a potential risk factor for transmitting T. gondii to humans in Gaza, Palestine.

HIGHLIGHTS

Observation of Giardia sp. in the termite gut of Heterotermes tenuis

Giardia comprises one genus with several morphologically distinct species described in mammals (including humans, marsupials, rodents), birds, and amphibians. This group of protists provokes diarrhoea diseases in humans and animals worldwide. Transmission of the parasite occurs through the faecal-oral route. Regarding the presence of Giardia in invertebrates, some works have shown that flies can transmit Giardia cysts by contact and transport between contaminated faeces and food. In this way, flies would eventually transmit this parasite. To date, Giardia's presence in the gut of other invertebrates has not been described in the literature. Here we show by first time, using scanning electron microscopy, the presence of Giardia-like trophozoites in the gut of termite Heterotermes tenuis. Two groups of Giardia were found based exclusively on the size and the flange shape of the protozoa: one presented eight flagella, a ventral disc, size, and shape very similar to Giardia intestinalis. In contrast, other cells were smaller and showed some differences in the external morphology. We cannot exclude the possibility that they correspond to the same species and that these differences result from protozoan heterogeneity.

Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance

This paper reviews the occurrence of antimicrobial resistance (AMR) in insects, rodents, and pets. Insects (e.g., houseflies, cockroaches), rodents (rats, mice), and pets (dogs, cats) act as reservoirs of AMR for first-line and last-resort antimicrobial agents. AMR proliferates in insects, rodents, and pets, and their skin and gut systems. Subsequently, insects, rodents, and pets act as vectors that disseminate AMR to humans via direct contact, human food contamination, and horizontal gene transfer. Thus, insects, rodents, and pets might act as sentinels or bioindicators of AMR. Human health risks are discussed, including those unique to low-income countries. Current evidence on human health risks is largely inferential and based on qualitative data, but comprehensive statistics based on quantitative microbial risk assessment (QMRA) are still lacking. Hence, tracing human health risks of AMR to insects, rodents, and pets, remains a challenge. To safeguard human health, mitigation measures are proposed, based on the one-health approach. Future research should include human health risk analysis using QMRA, and the application of in-silico techniques, genomics, network analysis, and ’big data’ analytical tools to understand the role of household insects, rodents, and pets in the persistence, circulation, and health risks of AMR.

Seasonal Fluctuations in Sarcophagidae (Diptera: Calyptratae) Assemblages in the Humid Chaco Ecoregion, Argentina

The seasonal fluctuations of flesh fly (Diptera: Sarcophagidae) assemblages were investigated from March 2015 to February 2016 in five habitat types in the Humid Chaco ecoregion, Chaco Province, Argentina. Three of the habitats were anthropized: an urban area, a cattle farm, and an alfalfa crop; and two were natural: a savanna and a forest. Flesh flies were collected monthly at 25 sampling points, five per habitat. In total, 5,790 male specimens comprising 55 species distributed in 15 genera were collected. The assemblage composition of flesh flies in each habitat and season was analyzed in terms of abundance, species richness, and diversity. In addition, the correlation between these community parameters and climatic factors (precipitation 7 and 14 d before samplings, temperature, and relative humidity) were evaluated in each habitat. The highest abundance and species richness of Sarcophagidae were registered in May (autumn) and June (winter), respectively. The lowest diversity values were observed between August and September (end of winter and early spring) in all habitats. However, flesh flies were present and well represented (in terms of species richness) throughout the year in all habitat types. Fluctuations in the abundance of the most abundant species collected were analyzed. The climatic factors were correlated with diversity and species richness in the urban, cattle farm, and savanna habitats. This study revealed that flesh fly assemblages differed temporally between different types of habitats in accordance with climatic factors and microclimate conditions.

Prevalence of Gastrointestinal Parasites in the Frugivorous and the Insectivorous Bats in Southcentral Nepal

Bats are the only active flying placental mammals and are traditionally classified into mega- and microbats, which are, respectively, herbivorous and insectivorous in feeding habit. Though deforestation, habitat destruction, natural calamities, illegal hunting, and climate changes are the challenging threats for bats, the role of existing gastrointestinal (GI) parasites have not been evaluated yet in Nepal. Thus, the current study aims to determine the prevalence of GI parasites in bats from the Shaktikhor area at the Chitwan district of Southcentral Nepal. From July 2018 to February 2019, a total of 60 fecal samples of bats (30 from frugivorous bats and 30 from the insectivorous bats) were collected. These samples were preserved at 2.5% potassium dichromate solution. The fecal examination was carried out by the direct wet mount, concentrations, acid-fast staining, and sporulation techniques. Overall results showed the prevalence rate of 80% GI parasites. The parasites detected in the insectivorous bats were Ascarid spp., Capillarid sp., Cryptosporidium sp., Eimeria spp., Entamoeba sp., Giardia sp., Hymenolepis spp., Isospora sp., Oxyurid sp., Strongyle, and Strongyloides sp. In contrast, Eimeria sp., Entamoeba sp., and Hymenolepis sp. were detected in the frugivorous bats. Based on a wide diversity of parasite richness and parasitic concurrency measured by the prevalence rates, we suggest that GI parasitism might be a threatening factor in the insectivorous bats in the current study area.

Seroprevalence, Risk Factors, and Genotypes of Toxoplasma gondii in Free-Range Chickens Intended for Human Consumption in China

Toxoplasma gondii is a protozoan with worldwide distribution that infects birds and mammals, including humans. The consumption of free-range chicken meat is a common practice in many parts of the world. However, little information is available concerning the molecular prevalence and genotypes of T. gondii infection in free-range chickens intended for human consumption in China. In this study, a total of 1360 serum samples were collected from food markets in Hunan province of China for detecting T. gondii antibodies by indirect hemagglutination assay. In addition, 650 brain tissues were also collected to investigate T. gondii DNA by amplification of B1 gene with a seminested polymerase chain reaction (PCR), and the positive DNA samples were typed at 10 genetic markers using multilocus PCR-restriction fragment length polymorphism. Antibodies to T. gondii were detected in 457 of the examined serum samples (33.6%; 95% confidence interval [CI]: 31.1-36.1), and 72 DNA samples (11.1%; 95% CI: 8.6-13.4) were positive for the T. gondii B1 gene. In this study, region and age of free-range chickens were shown to be risk factors for T. gondii infection (p < 0.01). Two genotypes (ToxoDB#9 and ToxoDB#52) were identified from two samples with complete genotyping results. Our study revealed a high prevalence of T. gondii infection in free-range chickens intended for human consumption in Hunan province, suggesting that recommendations to consumers should be made, especially in some regions of China where consumption of undercooked chicken meat is common. This is the first genetic characterization of T. gondii in free-range chickens intended for human consumption in Hunan province, China, and also the first report of genotype ToxoDB#52 in China.

Effects of Antibiotics on the Dynamic Balance of Bacteria and Fungi in the Gut of the German Cockroach

The German cockroach, Blattella germanica (L.) (Blattaria: Blattidae) harbored diverse microorganisms in the digestive tract, including bacteria, fungi, viruses, archaea, and protozoa. This diverse community maintains a relatively stable balance. Some bacteria have been confirmed to play crucial roles in the insect's physiology, biochemistry, and behavior. Antibiotics can effectively eliminate bacteria and disrupt the balance of gut microbiota, but the time-course of this process, the structure of the new microbial community, and the dynamics of re-assemblage of a bacterial community after antibiotic treatment have not been investigated. In the present study, antibiotic (levofloxacin and gentamicin) ingestion reduced bacterial diversity and abundance in the cockroach gut. Within 14 d of discontinuing antibiotic treatment, the number of culturable gut bacteria returned to its original level. However, the composition of the new bacterial community with greater abundance of antibiotic-resistant Enterococcus and Dysgonomonas was significantly different from the original community. Network analysis showed that antibiotic treatment made the interaction between bacteria and fungi closer and stronger in the cockroach gut during the recovery of gut microorganisms. The study on the composition change, recovery rules, and interaction dynamics between gut bacteria and fungi after antibiotic treatment are helpful to explore gut microbes' colonization and interaction with insects, which contributes to the selection of stable core gut bacteria as biological carriers of paratransgenesis for controlling Blattella germanica.

Honey bees (Apis cerana) use animal feces as a tool to defend colonies against group attack by giant hornets (Vespa soror)

Honey bees (genus Apis) are well known for the impressive suite of nest defenses they have evolved to protect their abundant stockpiles of food and the large colonies they sustain. In Asia, honey bees have evolved under tremendous predatory pressure from social wasps in the genus Vespa, the most formidable of which are the giant hornets that attack colonies in groups, kill adult defenders, and prey on brood. We document for the first time an extraordinary collective defense used by Apis cerana against the giant hornet Vespa soror. In response to attack by V. soror, A. cerana workers foraged for and applied spots of animal feces around their nest entrances. Fecal spotting increased after colonies were exposed either to naturally occurring attacks or to chemicals that scout hornets use to target colonies for mass attack. Spotting continued for days after attacks ceased and occurred in response to V. soror, which frequently landed at and chewed on entrances to breach nests, but not Vespa velutina, a smaller hornet that rarely landed at entrances. Moderate to heavy fecal spotting suppressed attempts by V. soror to penetrate nests by lowering the incidence of multiple-hornet attacks and substantially reducing the likelihood of them approaching and chewing on entrances. We argue that A. cerana forages for animal feces because it has properties that repel this deadly predator from nest entrances, providing the first report of tool use by honey bees and the first evidence that they forage for solids that are not derived from plants. Our study describes a remarkable weapon in the already sophisticated portfolio of defenses that honey bees have evolved in response to the predatory threats they face. It also highlights the strong selective pressure honey bees will encounter if giant hornets, recently detected in western North America, become established.

The Persistence of Escherichia coli Infection in German Cockroaches (Blattodea: Blattellidae) Varies Between Host Developmental Stages and is Influenced by the Gut Microbiota

The German cockroach, Blatella germanica (L.), is a suspected vector of several enteric bacterial pathogens, including Escherichia coli, among livestock and humans. However, little is known about the factors that influence bacterial transmission by cockroaches. Here, we orally infected B. germanica with various laboratory and field strains of E. coli and examined bacterial titers over time to shed new light on the factors that influence the dynamics of infection. Our results reveal that a laboratory strain of E. coli is largely cleared within 48 h while one field isolate can persist in a majority of cockroaches (80-100%) for longer than 3 d with minimal impact on cockroach longevity. We also find that the ability to clear some strains of E. coli is greater in cockroach nymphs than adults. Notably, no differential expression of the antimicrobial gene lysozyme was observed between nymphs and adults or in infected groups. However, clearance of E. coli was significantly reduced in gnotobiotic cockroaches that were reared in the absence of environmental bacteria, suggesting a protective role for the microbiota against exogenous bacterial pathogens. Together, these results demonstrate that the interactions between cockroaches and enteric bacterial pathogens are highly dynamic and influenced by a combination of microbial, host, and environmental parameters. Such factors may affect the disease transmission capacity of cockroaches in nature and should be further considered in both lab and field studies.

Survey of anti-Toxoplasma gondii antibodies in wild mammals captured from Atlantic Forest fragments in Bahia, northeastern Brazil

The objective of this study was to investigate the frequency of antibodies to Toxoplasma gondii present in wild mammals that were trap captured in forest fragments in the State of Bahia, northeastern Brazil. A total of 368 individuals (246 rodents, 104 marsupials and 18 bats) were captured using live catch traps. Serum samples were tested using the modified agglutination test, with a cut-off point at 1:25 dilution. The total occurrence of antibodies to T. gondii was 10.6% (39/368), being 16.3% (17/104) in marsupials, 8.5% (21/246) in rodents, and 5.5% (1/18) in bats. Antibody titers varied between 25 and 50 for rodents, between 25 and 400 for marsupials, and were 25 for bats. This is the first report on antibodies to T. gondii in certain rodent species (Thaptomys nigrita, Hylaeamys laticeps, and Cerradomys subflavus), marsupial species (Monodelphis americana, Gracilinanus microtarsus, Gracilinanus agilis and Marmosops incanus), and bats of the genus Rhynchonycteris. The presence of antibodies to T. gondii in wild mammals demonstrates the possibility of these animals as sentinels of toxoplasmosis, especially on regions under high anthropogenic effect.

Metamorphosis-related changes in the free fatty acid profiles of Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830)

The flies of the Sarcophagidae, widespread throughout the temperate zone, are of great significance in Medicine, Veterinary science, Forensics and Entomotoxicology. Lipids are important elements of cell and organelle membranes and a source of energy for embryogenesis, metamorphosis and flight. Cuticular lipids protect from desiccation and act as recognition cues for species, nest mates and castes, and are a source of various pheromones. The free fatty acid (FFA) profile of cuticular and internal extracts of Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830) larvae, pupae and adults was determined by gas chromatography-mass spectrometry (GC-MS). The larvae, pupae and adults contained FFAs from C5:0 to C28:0. The extracts differed quantitatively and qualitatively from each other: C18:1 > C16:1 > C16:0 > C18:0 predominated in the cuticular and internal extracts from the larvae and adults, while 18:1 > C16:0 > C16:1 > C18:0 predominated in the pupae. The FFA profile of the cuticle varies considerably between each development stage: C23:0 and C25:0 are only present in larvae, C28:0 in the pupal cuticle, and C12:1 and C18:3 in internal extracts from adults. The mechanisms underlying this diversity are discussed herein.

Antimicrobial resistant and enteropathogenic bacteria in 'filth flies': a cross-sectional study from Nigeria

‘Filth flies’ facilitate the dispersal of pathogens between animals and humans. The objective was to study the intestinal colonization with antimicrobial resistant and enteropathogenic bacteria in ‘filth flies’ from Nigeria. Flies from Southern Nigeria were screened for extended-spectrum β-lactamase producing Enterobacterales (ESBL-E), Staphylococcus aureus, Salmonella sp., Shigella sp., Campylobacter sp. and Yersinia enterocolitica by culture. ESBL-E were tested for bla_SHV, bla_CTX-M and bla_TEM; S. aureus was screened for enterotoxins. Spa typing and multilocus sequence typing (MLST) was done for S. aureus and MLST for Escherichia coli. Of 2,000 flies, 400 were randomly collected for species identification. The most common species were Musca domestica (44.8%, 179/400), Chrysomya putoria (21.6%, 85/400) and Musca sorbens (18.8%, 75/400). Flies were colonized with S. aureus (13.8%, 275/2,000) and ESBL-E (0.8%, 16/2,000). No other enteropathogenic bacteria were detected. The enterotoxin sei was most common (26%, 70/275) in S. aureus, followed by sea (12%, n = 32/275). Four S. aureus isolates were methicillin resistant (mecA positive, t674 and t5305, ST15). The bla_CTX-M (n = 16) was the most prevalent ESBL subtype, followed by bla_TEM (n = 8). ‘Filth flies’ can carry antimicrobial resistant bacteria in Nigeria. Enterotoxin-positive S. aureus might be the main reason for food poisoning by ‘filth flies’ in the study area.

Zoonotic Diseases: Etiology, Impact, and Control

Most humans are in contact with animals in a way or another. A zoonotic disease is a disease or infection that can be transmitted naturally from vertebrate animals to humans or from humans to vertebrate animals. More than 60% of human pathogens are zoonotic in origin. This includes a wide variety of bacteria, viruses, fungi, protozoa, parasites, and other pathogens. Factors such as climate change, urbanization, animal migration and trade, travel and tourism, vector biology, anthropogenic factors, and natural factors have greatly influenced the emergence, re-emergence, distribution, and patterns of zoonoses. As time goes on, there are more emerging and re-emerging zoonotic diseases. In this review, we reviewed the etiology of major zoonotic diseases, their impact on human health, and control measures for better management. We also highlighted COVID-19, a newly emerging zoonotic disease of likely bat origin that has affected millions of humans along with devastating global consequences. The implementation of One Health measures is highly recommended for the effective prevention and control of possible zoonosis.

The Effect of Anthropization on Sarcophagidae (Diptera: Calyptratae) Community Structure: An Assessment on Different Types of Habitats in the Humid Chaco Ecoregion of Argentina

Sarcophagidae (Diptera) are of great interest from a veterinary, medical, and forensic viewpoint, and are potential bioindicators for environmental impact assessments. In this study, we evaluated changes in abundance, species richness, and diversity of flesh flies in different habitat types in the Humid Chaco ecoregion of South America: 1) anthropized habitats: urban, cattle farm, and alfalfa crop, and 2) natural habitats: savanna and forest. We hypothesized that sarcophagid fly community parameters are affected by the anthropization and that spatial turnover will contribute more to the overall beta diversity than nestedness between habitats. In each habitat, samplings were conducted monthly from March 2015 to February 2016 in 25 sites, 5 per habitat, totaling 300 independent samples at the end of the study. We collected 5,790 Sarcophagidae (55 species). Community parameters of Sarcophagidae were evaluated and compared. The ecological effects of anthropization and habitat type were observed in the present study. As expected, our results showed the highest abundance, species richness, and diversity in the savanna and forest habitats (natural), whereas the lowest values were registered in the urban and alfalfa crop habitats, supporting the hypotheses of anthropization as the main driver of diversity loss. In addition, sarcophagid assemblages differed between all habitats and the overall dissimilarity was structured by spatial turnover. The main conclusion of this research is that flesh fly community structure is greatly affected by anthropization and habitat type, and this would be related to canopy cover and microclimate conditions of each environment.

Lophomonas sp. in the upper and lower respiratory tract of patients from a hospital in Lambayeque, Peru: clinical case studies

Infections with protozoans, mainly due to immunodeficiency, are common all over the world. However, pulmonary infections with protozoans are less frequent. Lophomonassp. is a flagellated protozoan that lives in the gastrointestinal tract of some species of cockroaches. Some cases, that show the presence of Lophomonas in populations whose lungs are affected, have been reported. Case report: The medical records of nine patients were studied: seven adult patients and two pediatric patients who were in the Intensive Care Unit (ICU) and in the Neonatal Intensive Care Unit (NICU), respectively. The samples were taken from tracheal aspirations and bronchoalveolar lavages. The patients’ ages were between 9 and 95 years, and 60% of them were male. Some of the patients were healthy, a priori, and others were immunosuppressed. There were found three patients with neoplasia, two patients with diabetes mellitus and four patients with no systemic pathologies. It is concluded that Lophomonas sp. is a protozoa parasite which emerges from the upper and lower respiratory tract of hospitalized patients. However, its pathogenic role is still controversial in all cases, that's why it merits further study for its understanding and possible treatment.

Potential of Black Soldier Fly Production for Pacific Small Island Developing States

Organic waste such as food waste and livestock manure is a serious concern in the Pacific Islands, where landfills are overflowing and illegal dumping of waste threatens the fragile ecosystems. Organic waste also attracts filth flies, some of which are vectors for pathogens that cause human disease. The black soldier fly, Hermetia illucens, has tremendous potential for the Pacific Islands. Capable of digesting almost any organic matter and converting it into insect biomass, black soldier flies are already being used around the world to process organic waste into larvae. The system can be adapted to large-scale municipal composting as well as small sizes for individual livestock farms or even urban households. The larvae can be fed live to fish or poultry, processed into feed comparable to fishmeal or soy meal, or even used to generate biofuel. Thus, the fly not only eliminates waste, but also can improve the sustainability of livestock production. The Pacific Small Island Developing States stand to benefit immensely from black soldier fly bioconversion facilities, used primarily as a means to compost organic waste; however, several knowledge gaps must first be addressed. We reviewed the state of black soldier flies in the Pacific and identified where their use shows the most promise. Research priorities for the field include fly surveys and bioconversion assays using Pacific crop waste.

Entomophagy: A Narrative Review on Nutritional Value, Safety, Cultural Acceptance and A Focus on the Role of Food Neophobia in Italy

In recent years, the consumption of insects, or entomophagy, has produced an increasing interest amongst scientists and ecologists as a potential source of animal protein. Eating insects is also interesting in terms of low greenhouse gas emissions and low land use. In contrast to tropical countries, where most of the 2000 edible insect species are traditionally consumed, the concept of eating insects is still new to Western culture and diet. Culture and eating habits exert a great influence on what is considered edible in the Mediterranean area, especially in Italy, where the preservation of culinary traditions is a predominant factor affecting dietary behaviour. The purpose of this narrative paper is to provide an overview of the main topics related to entomophagy. The introduction presents some information about the nutrient content and safety aspects, the second part summarises the cultural acceptance of insect in the world, while the role of food neophobia on the intention to consume insects in Italy is focused on in part three. The discussion displays important viewpoints of previously published studies and based on these perspectives it can be concluded that the Italian diet is still clearly influenced by local tradition. In conclusion, in order to introduce insects into the Italian diet, psychological motivation has to be enhanced.

Lophomonas blattarum: A new flagellate causing respiratory tract infections

Lophomonas blattarum is a flagellate protozoan parasite which was originally described as a commensal in the gut of cockroaches. From the 1990s, reports started coming out of peoples Republic of China about its possible role in bronchopulmonary infections, and this was followed by reports from some other parts of the world as well. There had been some skepticism regarding the misidentification of bronchial ciliated epithelial cells as L. blattarum, but recent use of molecular diagnosis has come as an aid in clearing the controversy. This review focuses on the various aspects of the parasite including its biology, epidemiology, clinical manifestations, laboratory diagnosis, and the treatment aspects. Molecular diagnosis has recently been employed and more reports concerning its validation is needed. More basic research concerning the genomic and proteomic analysis is necessary to develop reliable molecular and serological tests for this parasite in future.

The role of environmental factors to transmission of SARS-CoV-2 (COVID-19)

The current outbreak of the novel coronavirus disease 2019 (COVID-19) in more than 250 countries has become a serious threat to the health of people around the world. Human-to-human transmission of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs most often when people are in the incubation stage of the disease or are carriers and have no symptoms. Therefore, in this study, was discussed the role of environmental factors and conditions such as temperature, humidity, wind speed as well as food, water and sewage, air, insects, inanimate surfaces, and hands in COVID-19 transmission. The results of studies on the stability of the SARS-CoV-2 on different levels showed that the resistance of this virus on smooth surfaces was higher than others. Temperature increase and sunlight can facilitate the destruction of SARS-COV-2 and the stability of it on surfaces. When the minimum ambient air temperature increases by 1 °C, the cumulative number of cases decreases by 0.86%. According to the latest evidence, the presence of coronavirus in the sewer has been confirmed, but there is no evidence that it is transmitted through sewage or contaminated drinking water. Also, SARS-COV-2 transmission through food, food packages, and food handlers has not been identified as a risk factor for the disease. According to the latest studies, the possibility of transmitting SARS-COV-2 bioaerosol through the air has been reported in the internal environment of ophthalmology. The results additionally show that infectious bio-aerosols can move up to 6 feet. There have been no reports of SARS-COV-2 transmission by blood-feeding arthropods such as mosquitoes.

Detection of antibiotic-resistant bacteria and their resistance genes from houseflies

Background and Aim:

Houseflies (Musca domestica) are synanthropic insects which serve as biological or mechanical vectors for spreading multidrug-resistant bacteria responsible for many infectious diseases. This study aimed to detect antibiotic-resistant bacteria from houseflies, and to examine their resistance genes.

Materials and Methods:

A total of 140 houseflies were captured using sterile nylon net from seven places of Mymensingh city, Bangladesh. Immediately after collection, flies were transferred to a sterile zipper bag and brought to microbiology laboratory within 1 h. Three bacterial species were isolated from houseflies, based on cultural and molecular tests. After that, the isolates were subjected to antimicrobial susceptibility testing against commonly used antibiotics, by the disk diffusion method. Finally, the detection of antibiotic resistance genes tetA, tetB, mcr-3, mecA, and mecC was performed by a polymerase chain reaction.

Results:

The most common isolates were Staphylococcus aureus (78.6%), Salmonella spp., (66.4%), and Escherichia coli (51.4%). These species of bacteria were recovered from 78.3% of isolates from the Mymensingh Medical College Hospital areas. Most of the isolates of the three bacterial species were resistant to erythromycin, tetracycline, penicillin and amoxicillin and were sensitive to ciprofloxacin, ceftriaxone, chloramphenicol, gentamicin, and azithromycin. Five antibiotic resistance genes of three bacteria were detected: tetA, tetB, mcr-3, and mecA were found in 37%, 20%, 20%, and 14% isolates, respectively, and no isolates were positive for mecC gene.

Conclusion:

S. aureus, Salmonella spp., and E. coli with genetically-mediated multiple antibiotic resistance are carried in houseflies in the Mymensingh region. Flies may, therefore, represent an important means of transmission of these antibiotic-resistant bacteria, with consequent risks to human and animal health.

Solid Wastes Provide Breeding Sites, Burrows, and Food for Biological Disease Vectors, and Urban Zoonotic Reservoirs: A Call to Action for Solutions-Based Research

Background: Infectious disease epidemiology and planetary health literature often cite solid waste and plastic pollution as risk factors for vector-borne diseases and urban zoonoses; however, no rigorous reviews of the risks to human health have been published since 1994. This paper aims to identify research gaps and outline potential solutions to interrupt the vicious cycle of solid wastes; disease vectors and reservoirs; infection and disease; and poverty.

Methods: We searched peer-reviewed publications from PubMed, Google Scholar, and Stanford Searchworks, and references from relevant articles using the search terms (“disease” OR “epidemiology”) AND (“plastic pollution,” “garbage,” and “trash,” “rubbish,” “refuse,” OR “solid waste”). Abstracts and reports from meetings were included only when they related directly to previously published work. Only articles published in English, Spanish, or Portuguese through 2018 were included, with a focus on post-1994, after the last comprehensive review was published. Cancer, diabetes, and food chain-specific articles were outside the scope and excluded. After completing the literature review, we further limited the literature to “urban zoonotic and biological vector-borne diseases” or to “zoonotic and biological vector-borne diseases of the urban environment.”

Results: Urban biological vector-borne diseases, especially Aedes-borne diseases, are associated with solid waste accumulation but vector preferences vary over season and region. Urban zoonosis, especially rodent and canine disease reservoirs, are associated with solid waste in urban settings, especially when garbage accumulates over time, creating burrowing sites and food for reservoirs. Although evidence suggests the link between plastic pollution/solid waste and human disease, measurements are not standardized, confounders are not rigorously controlled, and the quality of evidence varies. Here we propose a framework for solutions-based research in three areas: innovation, education, and policy.

Conclusions: Disease epidemics are increasing in scope and scale with urban populations growing, climate change providing newly suitable vector climates, and immunologically naïve populations becoming newly exposed. Sustainable solid waste management is crucial to prevention, specifically in urban environments that favor urban vectors such as Aedes species. We propose that next steps should include more robust epidemiological measurements and propose a framework for solutions-based research.