First Report of Biochemical Mechanisms of Insecticide Resistance in the Field Population of Culex pipiens (Diptera: Culicidae) From Sari, Mazandaran, North of Iran

Background: Culex pipiens play an important role in transmission of infectious diseases. Vector control by chemical pesticides, leads inevitably to resistance development. Understanding the underlying resistance mechanisms can help improve the control programmes and insecticide resistance management. Methods: The total contents of cytochrome p450s and the activities of glutathione S-transferases, alpha- and beta-esterases and inhibition rates of acetylcholine esterase (by propoxur) were measured in the field population of Cx. pipiens collected from Sari County, North of Iran, in 2016 and the results were compared with those of the laboratory susceptible strain according to the biochemical assay methods of WHO for adult mosquitoes. Independent sample t-test was used to compare the mean values of enzyme activities/contents between filed and laboratory susceptible popula-tions. Results: The enzyme ratio of cytochrome p450s, alpha- and beta-esterases in the field population was 2.07, 3.72 and 1.36 respectively when compared with the results of the laboratory population. Although not statistically significant, the mean GSTs activities in the field population was marginally less than the laboratory population (ER=0.92). Ace-tylcholinesterase was insensitive to propoxur in 62.82% of the individuals of the tested field population. There was a significant difference (P< 0.05) between all values of the activities/contents of the enzyme in the field population except for GSTs compared with the laboratory susceptible strain. The highest enzyme activity was related to alpha esterase. Conclusion: The present study showed a range of metabolic mechanisms, comprising p450s and esterases combined with target site insensitivity of AChE, contributing to organophosphate, carbamate and pyrethroid resistance in the field population of Cx. pipiens.

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Comparison of the knockdown resistance locus (kdr) in Anopheles stephensi, An. arabiensis, and Culex pipiens s.l. suggests differing mechanisms of pyrethroid resistance in east Ethiopia

10.1101/2020.05.13.093898 ◽

2020 ◽

Author(s):

Tamar E. Carter ◽

Araya Gebresilassie ◽

Shantoy Hansel ◽

Lambodhar Damodaran ◽

Callum Montgomery ◽

...

Keyword(s):

Insecticide Resistance ◽

Culex Pipiens ◽

Anopheles Stephensi ◽

Pyrethroid Resistance ◽

Resistance Mechanism ◽

Target Site ◽

Resistance Locus ◽

Knockdown Resistance ◽

Resistance Mutations ◽

Vector Species

AbstractThe malaria vector, Anopheles stephensi, which is typically restricted to South Asia and the Middle East, was recently detected in the Horn of Africa. Controlling the spread of this vector could involve integrated vector control that considers the status of insecticide resistance of multiple vector species in the region. Previous reports indicate that the knockdown resistance mutations (kdr) in the voltage-gated sodium channel (vgsc) are absent in both pyrethroid resistant and sensitive variants of An. stephensi in east Ethiopia but similar information on other vector species in the same areas is limited. In this study, kdr and the neighboring intron was analyzed in An. stephensi, An. arabiensis, and Culex pipiens s. l. collected in east Ethiopia between 2016 and 2017. Sequence analysis revealed that all of Cx. pipiens s.l. (n = 42) and 71.6% of the An. arabiensis (n=67) carried kdr L1014F known to confer target-site pyrethroid resistance. Intronic variation was only observed in An. stephensi (segregating sites = 6, haplotypes = 3) previously shown to have no kdr mutations. In addition, no evidence of non-neutral evolutionary processes was detected at the An. stephensi kdr intron which further supports target-site mechanism not being a major resistance mechanism in this An. stephensi population. Overall, these results suggest differences in evolved mechanisms of pyrethroid/DDT resistance in populations of vector species from the same region. Variation in insecticide resistance mechanisms in East Ethiopian mosquito vectors highlight possible species or population specific biological factors and distinct environmental exposures that shape their evolution.

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Comparison of Visit Length and Waiting Time of Patients in Public and Private Clinics in the North of Iran

Health Scope ◽

10.5812/jhealthscope.112698 ◽

2021 ◽

Vol In Press (In Press) ◽

Author(s):

Raana Gholamzadeh Nikjoo ◽

Mobin Sokhanvar ◽

Khadijeh Motahari ◽

Yegane Partovi ◽

Mohammad Taghi Khodayari

Keyword(s):

Waiting Time ◽

Random Sampling ◽

Simple Random Sampling ◽

Public And Private ◽

Patients Satisfaction ◽

The North ◽

Mean Waiting Time ◽

Significant Difference ◽

North Of Iran ◽

The Mean

Background: The visit length is considered one of the indicators for assessing patients’ satisfaction. Factors such as waiting time for getting a visit affects the desirability of the visit. Objectives: This study aimed to investigate the visit length and waiting time of patients in public and private clinics in Tabriz. Methods: This is a descriptive-analytic study conducted in five clinics in 2018. A questionnaire-based survey was used to collect data from 386 participants recruited through simple random sampling. Mann-Whitney U and Kruskal-Wallis tests were applied to analyze the data using SPSS version 22.0. Results: Overall, the mean visit length was 25.5 and 25.4 min in public and private centers, respectively, while the mean waiting time was 141.2 and 156.4 min in public and private centers, respectively. There was no significant difference between public and private centers regarding the visit length (P > 0.05); however, there was a significant difference between public and private centers in terms of waiting time (P < 0.05). Conclusions: The waiting time was too much, especially in private clinics, which can negatively affect patient satisfaction. Therefore, suggested interventions may consist of using internet and telephone admission, scheduling a waiting list, and requiring physicians to be present on time.

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Clinical Epidemiology and Paraclinical Findings in Tuberculosis Patients in North of Iran

BioMed Research International ◽

10.1155/2015/381572 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 6

Author(s):

Farhang Babamahmoodi ◽

Ahmad Alikhani ◽

Jamshid Yazdani Charati ◽

Amir Ghovvati ◽

Fatemeh Ahangarkani ◽

...

Keyword(s):

Clinical Epidemiology ◽

Wide Spectrum ◽

Cross Sectional Study ◽

Common Symptom ◽

Cross Sectional ◽

Significant Difference ◽

North Of Iran ◽

History Of ◽

The Mean ◽

Mean Time

Background. Mycobacterium tuberculosis (M.TB) causes a wide spectrum of clinical diseases. The prevalence of TB is different in various parts of Iran and throughout the world. The present study aimed to determine the clinical epidemiology and paraclinical findings of TB. Methods. A cross-sectional study was conducted from 2008 to 2013. Patient demographic, clinical, and radiologic characteristics, picked up from the TB patient’s files, were collected using a standard questionnaire format. Data was entered and analyzed using the SPSS version 16 statistical software and P value < 0.05 was considered statistically significant. Results. Out of 212 patients enrolled in this study 62% were male and the mean age was about 50 years old. 98.6% were Iranian, and 46.2% were rural. Prevalence of smear-positive TB was 66.4%. Prevalence of positive PPD was 50.7% with no significant difference between HIV-positive and -negative patients (P = 0.8). Prevalence of diabetes mellitus was 17%. 36% of the patients had history of smoking and about 29.3% were addicted to narcotics. Cough was the most common symptom (94.5%) and 84% had sputum. 15 cases (7%) had extrapulmonary TB. The mean time between the onset of symptoms and admission was 46.5 days. The delay for admission between urban and rural populations was not significantly different (P = 0.68); but for those who were in prison, the delay was significant (P = 0.02). About 46% of the patients had cavitary lesions in CXRs. Conclusion. Timely diagnosis of TB especially in prisoners by understanding its most important epidemiologic characteristics and clinical features can help to make an early treatment and prevent spread of mycobacteria and their complications.

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Comparative proteomics reveals mechanisms that underlie insecticide resistance in Culex pipiens pallens Coquillett

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009237 ◽

2021 ◽

Vol 15 (3) ◽

pp. e0009237

Author(s):

Chongxing Zhang ◽

Qiqi Shi ◽

Tao Li ◽

Peng Cheng ◽

Xiuxia Guo ◽

...

Keyword(s):

Cytochrome P450 ◽

Insecticide Resistance ◽

Culex Pipiens ◽

Mosquito Control ◽

Expression Profiles ◽

Susceptible Strain ◽

Culex Pipiens Pallens ◽

Metabolic Resistance ◽

Tandem Mass Spectrometric ◽

Pipiens Pallens

Mosquito control based on chemical insecticides is considered as an important element of the current global strategies for the control of mosquito-borne diseases. Unfortunately, the development of insecticide resistance of important vector mosquito species jeopardizes the effectiveness of insecticide-based mosquito control. In contrast to target site resistance, other mechanisms are far from being fully understood. Global protein profiles among cypermethrin-resistant, propoxur-resistant, dimethyl-dichloro-vinyl-phosphate-resistant and susceptible strain of Culex pipiens pallens were obtained and proteomic differences were evaluated by using isobaric tags for relative and absolute quantification labeling coupled with liquid chromatography/tandem mass spectrometric analysis. A susceptible strain of Culex pipiens pallens showed elevated resistance levels after 25 generations of insecticide selection, through iTRAQ data analysis detected 2,502 proteins, of which 1,513 were differentially expressed in insecticide-selected strains compared to the susceptible strain. Finally, midgut differential protein expression profiles were analyzed, and 62 proteins were selected for verification of differential expression using iTRAQ and parallel reaction monitoring strategy, respectively. iTRAQ profiles of adaptation selection to three insecticide strains combined with midgut profiles revealed that multiple insecticide resistance mechanisms operate simultaneously in resistant insects of Culex pipiens pallens. Significant molecular resources were developed for Culex pipiens pallens, potential candidates were involved in metabolic resistance and reducing penetration or sequestering insecticide. Future research that is targeted towards RNA interference of the identified metabolic targets, such as cuticular proteins, cytochrome P450s, glutathione S-transferases and ribosomal proteins proteins and biological pathways (drug metabolism—cytochrome P450, metabolism of xenobiotics by cytochrome P450, oxidative phosphorylation, ribosome) could lay the foundation for a better understanding of the genetic basis of insecticide resistance in Culex pipiens pallens.

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Introduction of suitable species for planting in gaps of different size (case study: Loveh forest, Golestan, Iran)

Journal of Forest Science ◽

10.17221/89/2016-jfs ◽

2017 ◽

Vol 63 (No. 1) ◽

pp. 9-15

Author(s):

Parhizkar Pejman ◽

Sagheb-Talebi Khosro ◽

Shahini Yaser ◽

Teimouri Maryam

Keyword(s):

Soil Surface ◽

Medium Size ◽

Annual Increment ◽

Significant Difference ◽

Quantitative Characteristics ◽

North Of Iran ◽

Collar Diameter ◽

The Mean ◽

Mean Annual Increment

This study was carried out in Loveh forest, north of Iran. We measured the quantitative characteristics of seedlings including collar diameter (measured at 1 cm above the soil surface), height, and current annual height increment and calculated the mean annual increments of height and diameter. Ten gaps with the same climatic, edaphic and topographic conditions were selected. In each gap, two transects, 2 m wide, were laid along the longest (North-South) and the shortest (West-East) axis. Nine sampling microplots, 4 m<sup>2</sup> area, were established: one at the centre, four at the edges and four under the canopy within the transects. Results showed that the highest frequency of seedlings was seen in medium-size gaps (200–500 m<sup>2</sup>). Quantitative characteristics of oak seedlings were better in small and medium-size gaps. There was a significant difference in the length of spring shoots, mean annual increment of height and mean annual increment of diameter between the species. Hornbeam, wild service and wild cherry seedlings are recommended for faster gap recovery, as the results showed that these species had the highest values of studied variables.

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Implementation of a Diagnostic-Concentration Bioassay for Detection of Susceptibility to Pyrethroids in Soybean Aphid (Hemiptera: Aphididae)

Journal of Economic Entomology ◽

10.1093/jee/toz351 ◽

2020 ◽

Vol 113 (2) ◽

pp. 932-939 ◽

Cited By ~ 1

Author(s):

James Menger ◽

Patrick Beauzay ◽

Anitha Chirumamilla ◽

Cole Dierks ◽

John Gavloski ◽

...

Keyword(s):

Insecticide Resistance ◽

Assessment Tool ◽

Pyrethroid Resistance ◽

Monitoring Program ◽

Soybean Aphid ◽

Cross Resistance ◽

Laboratory Population ◽

Glass Vial ◽

Aphis Glycines Matsumura ◽

Primary Management

Abstract Soybean aphid, Aphis glycines Matsumura, remains the most economically damaging arthropod pest of soybean in the midwestern United States and southern Canada. Foliar applications of a limited number of insecticide modes of action have been the primary management tactic, and pyrethroid resistance was documented recently with full concentration–response leaf-dip and glass-vial bioassays. Full concentration–response bioassays can be cumbersome, and a more efficient assessment tool was needed. In this study, we implemented a diagnostic-concentration glass-vial bioassay using bifenthrin and λ-cyhalothrin. Bioassays were conducted with field-collected soybean aphid populations to assess the geographic extent and severity of resistance to pyrethroids. In 2017, 10 of 18 and 11 of 21 field populations tested with bifenthrin and λ-cyhalothrin, respectively, had mean proportion mortalities less than the susceptible laboratory population. In 2018, 17 of 23 and 13 of 23 field populations tested with bifenthrin and λ-cyhalothrin, respectively, had mean proportion mortalities less than the susceptible laboratory population. Populations collected after reported field failures of a pyrethroid insecticide generally had mean proportion mortalities less than the susceptible laboratory population. In both years, there was a strong correlation between chemistries, which suggests cross-resistance between these insecticides. The diagnostic-concentration glass-vial bioassays reported here will provide the foundation for an insecticide resistance monitoring program with the ability to determine practical levels and geographic extent of insecticide resistance.

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Assessment the Changing Trend of Susceptibility to Two Insecticides Among Field-Population Culex quinquefasciatus Compared with the Same Population Undergoing to Multiple Colonization

Journal of Arthropod-Borne Diseases ◽

10.18502/jad.v14i2.3736 ◽

2020 ◽

Author(s):

Atieh Shemshadian ◽

Mohammad Reza Abai ◽

Hassan Vatandoost ◽

Navid DinparastDjadid ◽

Mohammad Ali Oshaghi ◽

...

Keyword(s):

Culex Quinquefasciatus ◽

Pyrethroid Resistance ◽

Rapid Development ◽

Field Population ◽

Cross Resistance ◽

Pyrethroid Insecticides ◽

Significant Difference ◽

Changing Trend ◽

Susceptibility Tests

Background: During the past decade, rapid development of insecticide resistance have been reported among many species of mosquito vectors against four main categories of insecticides worldwide. The aim of the research was to assess the variation trend of susceptibility levels of Culex quinquefasciatus to two insecticides separately for the field population compared with subsequent generations of the same sample after multiple colonization. Methods: Larvae and pupae of Cx. quinquefasciatus were collected from house sewages and reared to adult which blood-fed on roosters. Ten percent sucrose fed female mosquitoes aged 2–3 days were used for susceptibility tests with DDT and deltamethrin. Susceptibility levels was assessed in the adult stage of field stran Cx. quinquefasciatus against DDT 4.0% and deltamethrin 0.05% and continued up to next six generations undergoing multiple rearing at insectary condition. Results: The susceptibility levels to DDT 4.0% did not change compared to the field with the lab population to six generations. Regarding deltamethrin 0.05%, no significant difference was shown between field strain (58.3%) and 3 rd generation (52.7%) compared to the 6th one (33.8%). Conclusion: This finding may reflect the role of the kdr gene in resistance to organochlorine which has cross-resistance with pyrethroid insecticides. The results of this study clearly showed the irreversible trend of pyrethroid resistance among colonized mosquitoes. This is the first study of the resistance status of Cx. quinquefasciatus in Iran.

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Mechanisms of Insecticide Resistance in a Strain of Cat Fleas (Siphonaptera: Pulicidae)

Journal of Entomological Science ◽

10.18474/0749-8004-30.1.43 ◽

1995 ◽

Vol 30 (1) ◽

pp. 43-48 ◽

Cited By ~ 7

Author(s):

Nancy C. Hinkle ◽

Richard W. Wadleigh ◽

Philip G. Koehler ◽

Richard S. Patterson

Keyword(s):

Insecticide Resistance ◽

Enzyme Inhibition ◽

Resistant Strain ◽

Glutathione Transferase ◽

Resistance Mechanisms ◽

Ctenocephalides Felis ◽

Susceptible Strain ◽

Significant Difference ◽

Cat Fleas

Possible mechanisms of insecticide resistance were investigated in a known-resistant strain of cat fleas, Ctenocephalides felis Bouché. In the acetylcholinesterase study, ability of two insecticides, propoxur and chlorpyrifosoxon, to inhibit the activity of the enzyme was investigated using the Ellman method. In both cases, at least twice the amount of insecticide was required for 50% enzyme inhibition in the resistant fleas vs the susceptible fleas. Additionally, there was a significant difference in levels of glutathione transferase in the resistant strain of fleas compared with the susceptible strain. These results indicate that both insensitive acetylcholinesterase and detoxification via glutathione transferase conjugation may be involved in the insecticide resistance mechanisms of this strain of fleas.

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Vowel Recognition Threshold as a Function of Temporal Segmentations

Journal of Speech and Hearing Research ◽

10.1044/jshr.1304.715 ◽

1970 ◽

Vol 13 (4) ◽

pp. 715-724 ◽

Cited By ~ 6

Author(s):

Richard L. Powell ◽

Oscar Tosi

Keyword(s):

Normal Hearing ◽

Recognition Threshold ◽

Vowel Sound ◽

Significant Difference ◽

The Mean ◽

Vowel Recognition ◽

Temporal Segment

Vowels were segmented into 15 different temporal segments taken from the middle of the vowel and ranging from 4 to 60 msecs, then presented to 6 subjects with normal hearing. The mean temporal-segment recognition threshold of 15 msecs with a range from 9.3 msecs for the /u/ to 27.2 milliseconds for the /a/. Misidenti-fication of vowels was most often confused with the vowel sound adjacent to it on the vowel-hump diagram. There was no significant difference between the cardinal and noncardinal vowels.

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Left Ventricular Dysfunction and Blood Glycohemoglobin Levels in Young Diabetics

Nuklearmedizin ◽

10.1055/s-0038-1629573 ◽

1991 ◽

Vol 30 (05) ◽

pp. 183-188

Author(s):

A. Aydrner ◽

A. Oto ◽

E. Oram ◽

O. Gedik ◽

C. F. Bekdik ◽

...

Keyword(s):

Ejection Fraction ◽

Left Ventricular Function ◽

Ventricular Function ◽

Left Ventricular ◽

Diabetic Patients ◽

Filling Fraction ◽

Time To Peak ◽

Significant Difference ◽

The Mean ◽

Hba1c Levels

Left ventricular function including regional wall motion (RWM) was evaluated by 99mTc first-pass and equilibrium gated blood pool ventriculography and glycohemoglobin (HbA1c) blood levels determined by a quantitative column technique in 25 young patients with insulin-dependent diabetes mellitus without clinical evidence of heart disease, and in healthy controls matched for age and sex. Phase analysis revealed abnormal RWM in 19 of 21 diabetic patients. The mean left ventricular global ejection fraction, the mean regional ejection fraction and the mean 1/3 filling fraction were lower and the time to peak ejection, the time to peak filling and the time to peak ejection /cardiac cycle were longer in diabetics than in controls. We found high HbA1c levels in all diabetics. There was no significant difference between patients with and without retinopathy and with and without peripheral neuropathy in terms of left ventricular function and HbA1c levels.

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