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Background: Cockroaches play a role in the mechanical transmission of microbial pathogens. This study was designed to determine the isolated bacteria and their susceptibility to conventional antibiotics from brown-banded cockroach, Supella longipalpa, in Qom province, central Iran. Methods: In this cross-sectional study, brown-banded cockroaches were bred in an insectary and caught from hospitals of Qom. The samples were taken from the surface and alimentary canal and then cultured on microbial culture media; next, grown specimens were identified using differential culture media. Finally, after performing diagnostic tests and identifying the bacteria species, their susceptibility to various antibiotics was evaluated. Results: A total of 120 adult cockroaches from the insectary and hospitals were included in the study. Ten bacterial genera were found; nine were Gram-negative and one was Gram-positive. The genus Klebsiella, Enterobacter, Staphylococcus, Citrobacter and Hafnia were isolated only from the hospital strain. On the other hand, Pseudomonas and Escherichia from both groups and other species such as Salmonella, Proteus and Shigella were isolated only from laboratory strains. The highest antibiotic resistance among Gram-positive cocci and Gram-negative bacilli were 100.0% and 98.1% for ampicillin and Ceftazidime, respectively. Conclusion: The results of this study showed that various pathogenic bacteria harbored by brown-banded cockroaches. Moreover, it was found that most of these bacteria belong to the Enterobacteriaceae family, which can be pathogenic and thus threaten human health. [ABSTRACT FROM AUTHOR]

Background: Owing to chitosan properties such as biocompatibility and antimicrobial activities, and several applications in biomedical field, some physicochemical and anti-bacterial properties, and the level of chitosan from three species of American cockroach, Periplaneta americana (Dictyoptera: Blattidae), the German cockroach, Blattella germanica (Dictyoptera: Ectobiidae) and the Mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae) were investigated. Methods: The cuticle of adults derived from specimens was dried and grounded. The powders were demineralized as well as deproteinized after deacetylation via NaOH. At last, the chitosan yields from insects were studied for antibacterial activity on Gram-positive bacteria (Proteus mirabilis, Klebsiella pneumoniae), and Gram-negative bacteria (Enterococcus faecalis and Staphylococcus epidermidis). The Fourier transform infrared spectroscopy (FTIR) was used to analyze the chitosan composition. Results: The chitosan ratios of the American and German cockroaches and the mealworm beetle were 5.80, 2.95, and 1.70% per 3 g of the dried bodies respectively. The chitin DD’s for the American cockroach, the German cockroach and the mealworm beetle were 36.8%, 31.5% and 27.3%, respectively. The bactericidal activity of chitosan obtained from the American cockroach at a concentration of 1% had the greatest effect on P. mirabilis compared to other concentrations, while chitosan obtained from the German cockroach at a concentration of 0.01% had the greatest effect on K. pneumoniae compared to other concentrations. Conclusion: According to the results, the anti-bacterial influence of the chitosan is based upon the insect species and chitosan concentration. Probably, the variation relates to the changes in the chitin structure among the three insect species. [ABSTRACT FROM AUTHOR]

Background: Due to the confirmation of the presence of the novel coronavirus in the feces and municipal sewerage system, and the feeding of domestic insects from fecal matter, as well as the ability of these insects to mechanically transmit microbes from the sewerage system. This study was aimed at molecular evaluation of the novel coronavirus infection isolated on cockroaches and flies collected from Kamkar-Arabnia Hospital in Qom City, Iran. Methods: Totally, 18 samples; (12 samples cockroaches and 6 flies) from the external surface of cockroaches and houseflies as well as their digestive system were prepared. After designed and synthetized exogenous heterologous internal control, the RNA was extracted to investigate the contamination of these samples with the novel coronavirus. To detect the virus, the E and RdRp genes were identified. Results: Investigation of coronavirus E gene using the multiplex one-step qPCR technique on the collected samples showed an amplification plot in CT= 35.70 related to the internal surfaces of cockroaches collected from the treatment and sick room of the hospital. Also, the design of internal control to ensure the accuracy of the extraction process was successful. Conclusion: According to the findings of the present study regarding detecting the presence of the coronavirus infection in the digestive system of domestic insects such as American cockroaches and considering their ability to mechanically transmit viruses, it is recommended to control the domestic insects that are in close contact with humans in crowded places such as hospitals and health centers during the Covid-19 pandemic. [ABSTRACT FROM AUTHOR]

Background: Cockroaches are one of the most common pests in many residential areas. In this study, the simultaneous effects of fungi, Metarhizium anisopliae and fenitrothion-coated baits on the mortality rate of the German cockroach nymphs were investigated. Methods: To determine the lethal level of fenitrothion insecticide, a bioassay test was performed on the last instar nymphs of the German cockroach reared at insectarium conditions. Various toxic concentrations of fenitrothion (0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.5%, and 2%) were used. Different concentrations of M. anisopliae (1×104, 1×105, 1×106, 1×107, 1×108 Conidia/ ml) were also applied to nymphs. Eventually, we combined the effective dose of fenitrothion (0.93%) with the effective concentration of M. anisopliae (6.6 ×106 Conidia/ml) to provide the fungus-coated bait to attract insects. Mortality was recorded 24–96 hours after exposure to the toxic bait. The resulting data were subjected to Probit analysis. Results: The results of applying M. anisopliae spores with fenitrothion composition showed that the mortality rate of German cockroach nymphs was significant. Therefore, the optimal dose of fenitrothion used in combination with M. anisopliae seems essential to reduce the German cockroach nymphs. Conclusion: The results of this study can be considered a suitable method as a mixture with low cost and minimal damage to the environment and other organisms. [ABSTRACT FROM AUTHOR]