9 research outputs found

    Evaluation of susceptibility status of Phlebotomus papatasi, the main vector of zoonotic Cutaneous Leishmaniasis, to different WHO recommended insecticides in an endemic focus, Central Iran

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    Background: Among neglected zoonotic diseases, leishmaniases caused by Leishmania parasite through infected female sand fly bite, are a group of diseases found in 98 countries and territories representing a critical burden of disease worldwide. Vector management plays a crucial role in reducing the burden of vector-borne diseases by WHO’s global plan. The objective of the current study was to assess the susceptibility status of wild phlebotomine sand flies from Esfahan Prov- ince, central Iran, to the recommended insecticides by WHO. Methods: Sand flies were collected by mouth aspirator in Matin Abad desert Eco-resort and were tested using WHO adult mosquito test kit against Dichlorodiphenyltrichloroethane (DDT) 4%, Deltamethrin 0.05%, Malathion 5% and Propoxur 0.1%. The number of knockdown sand flies were recorded during exposure time in ten minutes interval for DDT and Deltamethrin and they were allowed to recover for 24 hours. Knockdown Time50 (KD50) and KD90 were generated for them using Probit software. They were mounted and identified by valid keys. Results: Among the tested insecticides against female Phlebotomus papatasi, DDT, Deltame- thrin, and Malathion recorded the highest mortality rate of 100%, followed by Propoxur with 92.2% mortality for a one-hour exposure. For DDT, KD50 and KD90 were calculated 21.87 and 42.93 and for Deltamethrin, they were 23.74 and 56.50 minutes respectively. Total sand flies ex-posed with DDT and Deltamethrin shed their leg(s). Conclusion: It is concluded that Ph. papatasi from central Iran is susceptible to DDT, Deltame- thrin, Malathion, and Propoxur

    Evaluation of Repellency and Lethal Effects of Ultrasonic Waves on the Blat-tella germanica (Blattodea: Blattellidae)

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    Background: The German cockroach, Blattella germanica (Insecta: Blattodea, Blattellidae), which occurs widely in human buildings, is a small cockroach species. Cockroach control chemical pesticides are toxic to the environment, and it is sometimes impossible to prevent them. Controlling Blattella germanica through ultrasonic waves can be efficient and less dangerous for the environment. Methods: In this study, the repellency and lethal effect of ultrasonic waves on male and female German cockroaches was tested in a twin glass cubic chamber at laboratory condition. The wave frequencies tested ranged from 20 to 100kHz with 5kHz steps. A signal generator generated these frequencies, and the piezoelectric transmitter of these ultrasonic waves was positioned in the chamber's center on the upper side. Results: Fisher's test showed that there was the greatest repellency effect in both male and female at frequencies of 35 and 40kHz. According to the results of the regression test, the most lethal effect is at the frequencies of 40 and 75kHz. Conclusion: The operating ultrasonic frequencies investigated in this study can be used to repel and kill German cock­roaches as pests endangering human health and environment

    Phlebotomus (Adlerius) kabulensis (Diptera: Psychodidae) a new record sand fly species from Iran: Morphological and molecular aspects

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    Objective: To represent a new geographical record, Phlebotomus (Adlerius) kabulensis (P. kabulensis), which is suspected to be a potential vector of visceral leishmaniasis. Methods: For the first time, P. kabulensis specimens were collected using the sticky paper traps method in outdoor places in mountainous areas with vegetation coverage of three provinces in Iran. Identification of males was based on ecological, morphological, morphometric and molecular (mtDNA cytochrome b gene sequences) criteria. Generally, males have two ascoids on the 8th antennal segment and one ascoid on segments 9th to 15th, aedeagus with normal obtuse-angled sub-terminal notch and coxite with 27–50 groups of hairs on the distal half of its body. Results: Morphometric measurement revealed that P. kabulensis specimens were the same as compared with seven other morphological characters in three provinces of the country but lengths of the coxite were significantly different. The PCR result of the cytochrome b (Cyt b)-mtDNA fragment shows 550-bp length, with its special nucleotide arrangement. The male and female of P. kabulensis were newly discovered members of the subgenus Adlerius from Iran. Initial DNA analysis indicated how distinct this species is. Conclusions: The results show that the P. kabulensis female will be identified by comparing with other Adlerius female groups regarding its morphometric characters and molecular sequencing

    Prevalence and Antibiotic Resistance of Gram-Negative Pathogenic Bacteria Species Isolated from Periplaneta americana and Blattella germanica in Varanasi, India.

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    Background: Cockroaches are among the medically important pests found within the human habitations that cause serious public health problems. They may harbor a number of pathogenic bacteria on the external surface with anti- biotic resistance. Hence, they are regarded as major microbial vectors. This study investigates the prevalence and antibiotic resistance of Gram-negative pathogenic bacteria species isolated from Periplaneta americana and Blattella germanica in Varanasi, India. Methods: Totally, 203 adult cockroaches were collected form 44 households and 52 food-handling establishments by trapping. Bacteriological examination of external surfaces of Pe. americana and Bl. germanica were carried out using standard method and antibiotics susceptibility profiles of the isolates were determined using Kirby-Bauer disc diffusion methods. Results: Among the places, we found that 54% had cockroache infestation in households and 77% in food- handling establishments. There was no significant different between the overall bacteria load of the external surface in Pe. americana  (64.04%)  and  Bl.  germanica  (35.96%).  However  the  predominant  bacteria  on  cockroaches  were Klebsiella pneumonia, Escherichia coli,  Enterobacter aerogenes, and  Pseudomonas aeruginosa. However, Kl. pneumoniae and Ps. aeruginosa were the most prevalent, drug-resistant strains were isolated from the cockroaches with 100% resistance to sulfamethoxazole/ trimethoprim and ampicillin. For individual strains of bacteria, Escherichia coli was found to have multi-resistance to four antibiotic tested, Citrobacter freundii four, Enterobacter aerogenes and Proteus mirabilis to three. Conclusion: Cockroaches are uniformly distributed in domestic environment, which can be a possible vector for transmission of drug-resistant bacteria and food-borne diseases

    Study on Periplaneta americana (Blattodea: Blattidae) Fungal Infections in Hospital Sewer System, Esfahan City, Iran, 2017

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    Background. American cockroaches contaminated with pathogens inside hospital manholes can be one of the major problems that health care systems face. Objectives. The aim of this study was to investigate the fungal infections of American cockroaches in the Esfahan hospital sewage network. The principle goal of the study was about the roaches as a vector of fungi and other pathogens. Method. The type of study was descriptive-analytical. A total of 55 American cockroach specimens from the manhole walls of the sewerage system of 7 large hospitals were captured. Samples were taken from the surface of the body, digestive tract, and haemocoel of cockroaches. The specimens were then cultured on Sabouraud dextrose agar separately, and fungi were identified according to the macroscopic and microscopic characteristics. Results. All cockroaches collected from hospitals were infected with fungi. Among the 24 (13 infected and 11 noninfected) (44%) female cockroaches and 31 (18 infected and 13 noninfected) (56%) male cockroaches, it was identified that 40.00% was infected with Aspergillus niger, 3.64% with Rhizopus, 7.27% with Penicillium, and 5.45% with Mucor. 6 cockroaches had no yeast contamination. 17 (30.91%) cockroaches were contaminated with Candida glabrata, 23 (41.82%) cockroaches were contaminated with Candida krusei, and 22 (40%) cockroaches were contaminated with other yeast species. The results of this study showed that Candida krusei had the highest prevalence among the isolated fungi with 35.37% of the digestive system and Aspergillus niger with 70.97% of the surface of the cockroach body. Conclusion. The results emphasized the role played by cockroaches as potential pathogenic vectors in hospital environments. Therefore, suitable management is needed for controlling this insect to prevent disease transmission in hospitals

    Antimicrobial Activities of the Secondary Metabolite Extracted from a Nocardia Strain

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    Background & Objective: The emergence of antibiotic-resistant bacteria and limited treatment options for these infections is a challenging problem in the world. There is increasing interest in isolating bioactive molecules from actinobacteria and elucidating their antimicrobial mechanisms at the moment. The current study aimed to investigate the antimicrobial activities of a Nocardia strain (N4) that was previously isolated from the soil samples in Tehran, Iran.  Materials & Methods: The cultural, morphological, and physiological characteristics of the strain were determined and the identity of the strain was confirmed using 16SrRNA gene sequencing. The strain was screened for antimicrobial metabolite production. The in vitro anti-microbial activity of the extracted metabolite was assessed by agar well diffusion and minimum inhibitory concentrations methods. Finally, the structure of the extracted metabolite was confirmed by HPLC and mass spectrometry methods. Results: The isolate shared 99% sequence similarity with Nocardia soli. The strain showed broad-spectrum antimicrobial activities against some pathogenic bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 700603, Salmonella Typhimurium ATCC 14028 and Shigella sonnei RI366) and fungi (Aspergillus niger ATCC 1015 and Aspergillus fumigatus ATCC 1022) in the agar well diffusion method. The ethyl acetate extract of the strain exhibited the highest antimicrobial activity against E. coli (MIC= 4.67±3.055 μg/mL) and K. pneumoniae (MIC=3.33±1.155 μg/mL). The metabolite showed high similarity with C21H28N7O14. Conclusions: The current study confirmed the presence of a bioactive metabolite in strain N4, suggesting that this may be a promising candidate for discovering bioactive components with broad antibacterial activities against a variety of pathogens Keywords

    Rodents as vehicle for delivery of transgenic bacteria to make paratransgenic sand fly vectors of cutaneous leishmaniasis in field condition

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    Abstract Vector-borne diseases, among them leishmaniasis, cause more than 700,000 deaths annually. The lack of an effective vaccination and the increasing resistance of sand flies to insecticides require the urgent development of innovative approaches to contain the disease. The use of engineered bacteria that express anti-parasite molecules (paratransgenesis) shows much promise. However, a challenge for implementation of this strategy is to devise means to introduce modified bacteria into sand flies in the field. In this study, we use rodent food bait as a delivery strategy to introduce two mCherry-fluorescent bacteria, Serratia AS1 and Enterobacter cloacae, into adult sand flies in field settings. Bacteria-infected food was provided to Rhombomys opimus rodents. These bacteria transiently pass through the rodent alimentary tract and are delivered to larval habitats with the rodent feces. The feces are ingested by sand fly larvae and, in the case of Serratia AS1, are trans-stadially transmitted to adults. This is the first report of targeting delivery of Serratia AS1 in a paratransgenic system to control transmission of leishmaniasis under field condition. This novel strategy shows promise for delivering transgenic bacteria to Leishmania vectors in the field

    Morphological and Genotypic Variations among the Species of the Subgenus Adlerius (Diptera: Psychodidae, Phlebotomus) in Iran

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    Background: Female sand flies of subgenus Adlerius are considered as probable vectors of visceral leishmaniasis in Iran. The objective of this study was to determine the morphological and genotypic variations in the populations of this subgenus in the country. Methods: Sand flies collected using sticky traps from 17 provinces during 2008–2010. The morphometric measurements were conducted with an Ocular Micrometer. Data was analyzed by SPSS. The Cytb gene was used to estimate population genetic diversity and identify the female specimens. UPGMA phenetic tree was used for DNA haplotypes of Cytb gene. Results: Six species of subgenus Adlerius identified from which one species, P. (Adlerius) kabulensis, is new record. The identification key is provided for males. Results revealed the molecular systematic in the species of subgenus Adlerius and determine the relationship of three females of P. comatus, P. balcanicus and P. halepensis. Conclusion: The positions of three females and the males in the UPGMA tree are correct and the similarities among them confirm our results. The branches of each species are not genetically distinct which justify the overlapping morphological characters among them. Molecular sequencing of Cytb-mtDNA haplotypes can be used for female identification for different species of subgenus Adlerius in Iran
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