Bacterial Contamination of Adult House Flies (Musca domestica) and Sensitivity of these Bacteria to Various Antibiotics, Captured from Hamadan City, Iran

kdr mutations and deltamethrin resistance in house flies in Abu Dhabi, UAE

BACKGROUND

The house fly, Musca domestica, is a significant carrier of diseases that can impact public health. Repeated use of pyrethroid insecticides may act as a selection pressure for mutations and amino acid substitutions in the house fly voltage-sensitive sodium channel (VSSC), which ultimately confers resistance. The objectives of this study were to determine the presence of knockdown resistance (kdr) mutations using molecular tools and to set up a CDC bottle bioassay specific for house flies in the United Arab Emirates (UAE) to screen for deltamethrin resistance.

METHODS

Adult flies were collected from 19 locations in Abu Dhabi, UAE, and DNA was extracted, followed by PCR amplification of specific alleles (PASA) and conventional PCR using several primers to amplify regions of the VSSC gene. Sanger sequencing was performed on PCR products. We also designed primers that detect four kdr mutations using complementary DNA (cDNA) in reverse transcriptase (RT)-PCR followed by Sanger sequencing. Additionally, a CDC bottle bioassay was set up for detecting deltamethrin resistance in adult house flies.

RESULTS

In PASA, the primers successfully amplified the target bands (480, 280 and 200 bp). The kdr allele was found in flies collected from 18 of the 19 locations, at the highest and lowest prevalence of 46.9% and 9.4%, respectively. Resistant homozygous (RR) insects constituted 5.0% of the tested populations, and heterozygous (RS) insects accounted for 36.5%. The RR genotype was prevalent in house flies collected at 10 of 19 sampling locations. House fly populations were mostly in Hardy-Weinberg equilibrium, except in three locations. In addition to verifying the presence of the previously identified kdr mutation L1014F, in this study we detected two kdr mutations, L1014H and T929I, that have not previously been reported in the UAE. Also, for the first time in the UAE, a CDC bottle bioassay for deltamethrin resistance was used, which found that 60 min and 4.5 µg/ml were the diagnostic time and dose, respectively. Using this assay, we detected deltamethrin resistance in house flies from two of 16 locations, with a resistance level of 12.5%.

CONCLUSIONS

Using DNA sequencing, we confirmed the presence of a known kdr mutation and uncovered two new kdr mutations in house flies from Abu Dhabi. Additionally, we detected deltamethrin resistance in these flies using a CDC bottle bioassay. Further research is recommended to comprehensively identify more kdr mutations in UAE house fly populations and assess their impacts on control strategies.

Bacterial Contamination of Collected Cockroaches and Determination Their Antibiotic Susceptibility in Khorramabad City, Iran

Background

Cockroaches are one of the most important carriers of pathogenic microorganisms. Therefore, the presence of cockroaches in public places, especially in hospitals, homes, and restaurants, is dangerous, and threatens the health of society, people, and the environment. The aim of this study was evaluation of bacterial contamination of cockroaches and the sensitivity of these bacteria to various antibiotics, captured from Khorramabad City, Iran.

Methods

This descriptive cross-sectional study was performed on 150 cockroaches collected from hospital environments, homes, and restaurants in Khorramabad. The outer surface of the cockroaches was washed with physiological saline. The suspension was centrifuged for 5 minutes at 2000rpm. Isolation and identification of bacteria was performed using phenotypic methods. Antibiotic susceptibility testing was performed by disk diffusion method according to Clinical and Laboratory Standard Institute (CLSI) guideline.

Results

A total of 100 American cockroaches (66.66%), 28 B. germanica (18.66%) and 22 Blatta orientalis (14.66%) were identified. In total, 97.33% of the collected cockroaches were infected with bacteria. The most bacterial infection of the cockroaches was Escherichia coli, coagulase-negative Staphylococci and Bacillus respectively. The overall results of the antibiogram test showed that the identified bacteria were resistant to cephalothin, ampicillin, cefotaxime, and kanamycin antibiotics, semi-sensitive to ciprofloxacin and sensitive to tetracycline, gentamicin, nitrofurantoin, Trimethoprim/sulfamethoxazole, and Chloramphenicol.

Conclusion

Infection of cockroaches with pathogenic bacterial agents in hospital, residential, and restaurant environments, as well as the observation of bacterial resistance to some common antibiotics is worrying.

A Review of the Antimicrobial Potential of Musca domestica as a Natural Approach with Promising Prospects to Countermeasure Antibiotic Resistance

Drug-resistant pathogens have become a serious public health concern worldwide considering the rapid emergence and distribution of new strains, which outpace the development of antimicrobial drugs. It is a complex and serious clinical problem that can cause an epidemic of a disease; consequently, numerous research studies are conducted to determine the solution to these problems, including the development of new antibiotics derived from natural sources such as insects. The housefly (Musca domestica L.), an insect known as a cosmopolitan pest, possesses several qualities that can ameliorate diseases; consequently, they can be used as a bioactive component in the development of medicines. These qualities include its potential as a source of antibacterial agents. The external surface components, wings, internal organs, and whole body extract of M. domestica can all contribute antimicrobial potential due to bioactive compounds they produce. This article discusses several antimicrobial properties of M. domestica that could be utilized for healthcare benefits.

Incidence rates of dysentery among humans in Lemghaier province, Algeria

Introduction

Dysentery is an infectious clinical syndrome which can cause high morbidity and mortality, especially in developing countries. This research highlights the epidemiological features of dysentery in Lemghaier province, Algeria.

Methods

A retrospective study of the incidence rates of dysentery in Lemghaier province, Algeria and overall for the whole country for the period from January 2001 to December 2018 was carried out. On a local level data were provided by the Directorate of Health and Population of El-Oued province, Algeria. At the national level data were provided by the National Public Health Institute, Algeria.

Results

An overall number of 1,786 cases of dysentery were notified, with an incidence rate of 58.5 cases per 100,000 population (mean±SD: 58.54±47.20; 95% CI: 36.73-80.35). The high incidence rate was reported in autumn and summer, respectively, with 23.4 and 20.1 cases per 100,000 population. The high incidence rate observed in the persons aged 20-44 years with 76.4 cases per 100,000 population. Females were more likely to have dysentery than males, respectively, with 63.6 against 53.7 cases per 100,000 population. The highest incidence rate was reported in Lemghaier municipality (capital of the province) with 176.9 cases per 100,000 population.

Conclusions

The results from this research showed high incidence rates of dysentery in Lemghaier province, Algeria. Тhis fact is a serious reason for national public health organizations to take adequate and timely measures to reduce the incidence rates of dysentery in this part of the country.

Higher seasonal temperature enhances the occurrence of methicillin resistance of Staphylococcus aureus in house flies (Musca domestica) under hospital and environmental settings

Antimicrobial resistance (AMR) emergence in commensal and pathogenic bacteria is a global health issue. House flies (Musca domestica) are considered as biological and mechanical vectors for pathogens causing nosocomial infections, including methicillin-resistant Staphylococcus aureus (MRSA). However, the prevalence of antimicrobial resistance and the role of temperature on the occurrence of Staphylococcus aureus and MRSA in house flies in a hospital environment have not been studied. A total of 400 house flies were collected in winter and summer from four hospital-associated areas in Mymensingh, Bangladesh. Detection of S. aureus and MRSA in flies was done by culturing, staining, and PCR methods targeting nuc and mec genes (mecA and mecC), respectively. Disc diffusion test was used to detect resistance phenotype against six antimicrobials. Logistic regression models were constructed to assess the effect of temperature on the frequency of antimicrobial resistance, and on the presence of the nuc and mecA genes, and location of samples in and around a hospital environment. By PCR, S. aureus was detected in 208 (52%) samples. High frequencies of resistance (≥ 80% of isolates) to amoxicillin, azithromycin, and oxacillin were observed by disk diffusion test. Increase in temperature had a positive effect on the occurrence of S. aureus and MRSA isolates as well as on their resistance to individual and multiple antimicrobials. Among the study areas, hospital premises had increased odds of having S. aureus. Increased temperature of summer significantly increased the occurrence of MRSA in house flies in and around the hospital environment, which might pose a human and animal health risk.

Carriage of ESBL-producing Gram-negative bacteria by flies captured in a hospital and its suburban surroundings in Ethiopia

BACKGROUND

Local data from the Asella Teaching and Referral Hospital in the town of Asella, Ethiopia reveal a high prevalence of extended-spectrum β-lactamase- (ESBL) producing Gram-negative bacteria (GNB) in clinical isolates. To investigate a possible route of transmission, we determined the proportions ESBL-producing GNB in isolates from flies caught in the hospital and in the town of Asella.

METHODS

Flies were collected in August 2019 from the neonatal intensive care unit (NICU), the orthopedic ward, the hospital's waste disposal area, and from a butchery situated 1.5 km from the hospital. After trapping, the flies were macerated and suspended in sterile normal saline. The suspensions were inoculated on MacConkey agar and incubated overnight. Species identification and antimicrobial susceptibility testing were performed using Vitek®-MS and VITEK® 2.

RESULTS

In total, 103 bacterial isolates were obtained from 85 flies (NICU: 11 isolates from 20 flies, orthopedic ward: 10 isolates from 12 flies, waste disposal area: 37 isolates from 26 flies, butchery: 45 isolates from 27 flies). The proportions of ESBL-producing bacteria among isolates obtained from flies collected in the hospital compound were significantly higher (82%, 90%, and 57% in NICU, orthopedic ward and waste disposal area, respectively) compared to flies collected outside of the hospital compound (2% (@1/45) in the butchery) (p ≤ 0.001). The proportion of ESBL was 67% (6/9) among Raoultella spp. 67% (4/6) among Kluyvera spp., 56% (5/9) among Enterobacter spp., 50% (5/10) among E. coli, and 44% (8/18) among Klebsiella spp.. Of the 40 ESBL-genes detected, 85% were CTX-M-like, 83% TEM-like, 23% SHV-like, and 2% CTX-M-2-like. ESBL-producing bacteria showed higher rates of resistance against ciprofloxacin (66% vs. 5%), gentamicin (68% vs. 3%), piperacillin-tazobactam (78% vs. 5%), and trimethoprim-sulfamethoxazole (88% vs. 16%), compared to non-ESBL-producing bacteria.

CONCLUSION

A high proportion of ESBL was identified in isolates from flies caught in the hospital compound compared with isolates of flies collected at a distance of 1.5 km from the hospital. Flies can be potential vectors for transmission of multidrug-resistant (MDR) bacteria within hospitals. Further studies are needed to determine the source of MDR colonization in flies and possible impact of MDR for nosocomial infections.

Environmental and Sex Effects on Bacterial Carriage by Adult House Flies (Musca domestica L.)

Adult house flies frequent microbe-rich sites such as urban dumpsters and animal facilities, and encounter and ingest bacteria during feeding and reproductive activities. Due to unique nutritional and reproductive needs, male and female flies demonstrate different interactions with microbe-rich substrates and therefore dissemination potential. We investigated culturable aerobic bacteria and coliform abundance in male and female flies (n = 107) collected from urban (restaurant dumpsters) and agricultural (dairy farm) sites. Whole-fly homogenate was aerobically cultured and enumerated on nonselective (tryptic soy agar; culturable bacteria) and selective (violet-red bile agar, VRBA; coliforms) media. Unique morphotypes from VRBA cultures of agricultural flies were identified and tested for susceptibility to 14 antimicrobials. Female flies harbored more bacteria than males and there was a sex by site interaction with sex effects on bacterial abundance at the urban site. Coliform abundance did not differ by sex, site or sex within site. Both male and female flies carried antimicrobial-resistant (AMR) bacteria: 36/38 isolates (95%) were resistant to ≥1 antimicrobial, 33/38 were multidrug-resistant (≥2), and 24/38 isolates were resistant to ≥4 antimicrobials. Our results emphasize the role of house flies in harboring bacteria including AMR strains that pose a risk to human and animal health.

Frequency and Antimicrobial Resistance Patterns of Bacterial Species Isolated from the Body Surface of the Housefly (Musca domestica) in Akure, Ondo State, Nigeria

BACKGROUND

The emergence and spread of antibiotic resistant bacteria has become a serious problem worldwide. Houseflies are potential carriers of pathogenic and resistant bacteria and could be contributing to the global spread of these strains in the environments. We investigated the prevalence and antimicrobial resistant profiles of bacteria isolated from houseflies in Akure.

METHODS

Twenty-five houseflies were captured by a sterile nylon net from the slaughterhouse, garbage dump, human house, hospital, and eatery from 9:00am to 1:00pm when the flies were active and transported immediately to the laboratory in sterile containers for processing. Bacterial loads were enumerated by serial dilution and plating on nutrient agar and selective media. Bacteria species were isolated by conventional isolation technique. Antibiotic susceptibility test was determined by the Kirby-Bauer disc diffusion technique.

RESULTS

Sixty-seven bacterial species were isolated from 25 samples that were collected. The predominant bacterial species was Escherichia coli (n= 31, 45%), followed by Klebsiella pneumoniae (n= 17, 25%), Staphylococcus aureus (n= 11, 16%) and Pseudomonas aeruginosa (n= 3, 4.3%). The bacterial load of the samples ranged from 9.7×105CFU/mL to 1.65×106CFU/mL. The results revealed that all isolates of Pseudomonas aeruginosa, Salmonella spp, and Proteus mirabilis were resistant to streptomycin and cotrimoxazole, augmentin and amoxicillin respectively. None of the S. aureus isolates was resistant to cotrimoxazole, chloramphenicol, sparfloxacin, augmentin, and ofloxacin. All isolates were multi-drug resistant.

CONCLUSION

House flies that were collected from the slaughterhouse, garbage dump, human house, hospital, and eatery may participate in the dispersal of pathogenic and resistant bacteria in the study environment.

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.

Fermented crop straws by Trichoderma viride and Saccharomyces cerevisiae enhanced the bioconversion rate of Musca domestica (Diptera: Muscidae)

Crop straw is an abundant renewable resource whose usage is limited due to its high cellulose, hemicellulose, and lignin contents. Here, Trichoderma viride, Saccharomyces cerevisiae, and Musca domestica were used to transform crop straws, and we investigated their impact on housefly rearing performance and optimized their utilization. The weights of cellulose, hemicellulose, and lignin in fermented crop straw diets significantly decreased after bioconversion by M. domestica larvae. The highest bioconversion rate was recorded in corn straw diet (16.19%), followed by wheat straw diet (10.31%) and wheat bran diet (8.97%). Similarly, high larval weight (yield) and pupation rate and fecundity and fertility rate were recorded in fermented crop straw diets composed of corn straw and wheat bran in 1:1 proportions. These results indicated that fermenting crop straw with T. viride and S. cerevisiae represented an efficient strategy that enhanced crop straw bioconversion and improved the rearing capacity of the housefly larvae. The resulting larvae could further be used as proteinaceous feed in poultry and aquaculture industries. Graphical abstract.

Isolation of multi-drug resistant Klebsiella sp. from bovine mastitis samples in Rangpur, Bangladesh

Objective:

The objective of this study was to identify the multi-drug resistance (MDR) Klebsiella sp. from mastitis milk samples.

Materials and Methods:

In the current research, 48 clinical mastitis milk samples were collected from Rangpur division, Bangladesh. Confirmation of bovine mastitis (BM) was done by the California Mastitis Test (CMT). All the CMT positive isolates were subjected for the identification of Klebsiella sp. using through a series of cultural and biochemical tests. MDR Klebsiella sp. isolates were determined using the disk diffusion method, and minimum inhibitory zones were measured by following Clinical and Laboratory Standards Institute. MDR patterns of the isolates were also subjected to study by using housefly (Musca domestica).

Results:

Among the isolates, 62.5% (n = 30/48) revealed the presence of Klebsiella sp. Eight antimicrobial agents including Amoxicillin, Novobiocin, Erythromycin, Vancomycin, Cephradine, Tetracycline, Bacitracin, Methicillin, and housefly (M. domestica) showed complete resistance to Klebsiella sp. On the other hand, Chloramphenicol, Gentamicin, Ciprofloxacin, Azithromycin, Norfloxacin, Levofloxacin, and Nalidixic acid showed sensitivity.

Conclusion:

This study helps to treat BM with effective antibiotics and helps in an epidemiological study in Rangpur division as well as helps to create public health awareness.

Synergistic and antagonistic effects of insecticide binary mixtures against house flies (Musca domestica)

The house fly, Musca domestica Linnaeus, 1758 (Diptera, Muscidae), is known as a globally distributed parasite with veterinary and medical importance and the ability to develop resistance to insecticides Insecticide mixtures can contribute to enhancing the effectiveness of existing insecticides against house flies and to implementing insecticide resistance management. The present study was conducted to assess the efficacy of four insecticides with different modes of action, applied alone and in binary mixtures, against adults of the M. domestica laboratory strain by no-choice feeding bioassays. The interaction patterns of neonicotinoid acetamiprid, phenylpyrazole fipronil, avermectin ivermectin, and pyrrole chlorfenapyr in the binary mixtures were likewise analyzed by calculating the combination indices to find out combinations with the synergistic effect. The analysis of values of insecticide lethal concentrations for 50% mortality revealed that the toxicity of acetamiprid, fipronil, and ivermectin increased in the binary mixtures compared to when they applied alone, while the toxicity of chlorfenapyr depended on the second insecticide in the mixtures. The combination index values of five insecticide mixtures, fipronil/acetamiprid (1:10), fipronil/chlorfenapyr (1:4), ivermectin/acetamiprid (1:2.5), ivermectin/chlorfenapyr (1:3 and 1:10) were <1, which displays a synergism. Three insecticide mixtures, acetamiprid/chlorfenapyr (1:4), fipronil/ivermectin (1:4), fipronil/chlorfenapyr (1:40), had combination index values >1, which indicates an antagonism. The fipronil/chlorfenapyr (1:4) mixture was the more toxic to adults of M. domestica. The ivermectin/chlorfenapyr (1:10) mixture and the ivermectin/acetamiprid (1:2.5) mixture produced the highest synergistic effects. The results of the present study suggest that the interaction patterns (synergistic or antagonistic) in the insecticide mixtures can depend on both the combination of insecticides and their ratio. Further studies are required in order to evaluate the synergistic combinations against field populations of M. domestica.

Emergence of colistin-resistant Escherichia coli in poultry, house flies, and pond water in Mymensingh, Bangladesh

Objective:

Emergence of colistin-resistant Escherichia coli (CREC) has generated a sense of public alarm. The objective of this study was to detect the CREC and identification of the gene responsible for such resistance.

Materials and Methods:

A total of 150 samples comprising poultry cloacal swab, house flies (Musca domestica), and pond water were collected randomly from Mymensingh, Bangladesh and analyzed. Isolation and identification of E. coli were done based on culture and E. coli 16S rRNA gene-specific polymerase chain reaction (PCR). Phenotypic detection of CREC was done by disk diffusion method. Finally, colistin resistance genes were detected by PCR by using colistin resistant gene mcr3 specific primers.

Results:

Among the 150 samples, phenotypically 18.00% (n = 27/150) isolates were found as colistin resistant. By PCR, 8.00% of the E. coli isolates were found positive for the presence of mcr3 gene.

Conclusions:

Colistin resistant E. coli carrying mcr3 are detected in poultry, house flies and water that are of great public health concern.

Efficacy of acetamiprid and fipronil fly baits against the housefly (Musca domestica L.) under laboratory conditions

Background:

The housefly Musca domestica L. (Diptera: Muscidae) is permanent pests in livestock facilities. High fly density in livestock and poultry farms can increase the risks of economic loss and public health. Treatment with toxic baits is one of the methods for housefly control. However, development of resistance to insecticides makes it difficult to manage of flies. Anti-resistance strategies include the use of multiple pesticides with different modes of action.

Aim:

This study was conducted to estimate the efficacy of neonicotinoid acetamiprid and phenylpyrazole fipronil, applied alone or in the mixture, against adults of M. domestica and to evaluate the efficacy of fly bait formulations containing acetamiprid and fipronil under laboratory conditions.

Materials and Methods:

The adult flies, M. domestica of laboratory strain, were used in laboratory bioassays. The efficacy of acetamiprid and fipronil as technical substances, when applied alone and in the mixture, against adult flies was tested by no-choice feeding bioassays. The insecticidal efficacy of bait formulations (wet powder) with acetamiprid or fipronil or their mixture was tested against flies by choice feeding bioassays. The probit analysis was used to calculate lethal concentrations of insecticides, and the χ² test was used to analyze the interaction between fipronil and acetamiprid in the mixture.

Results:

Fipronil was more toxic to adults of M. domestica than acetamiprid in laboratory tests. Lethal concentrations for 50% mortality (95% confidence interval) of flies were 0.0159% (0.0124-0.0205) of acetamiprid and 0.000119% (0.000039-0.0002640) of fipronil. The mixture containing fipronil at concentration 0.005% and acetamiprid at concentration 0.05% had the additive effect on fly mortality.

Conclusion:

The results of laboratory feeding bioassays indicate that the mixture of fipronil and acetamiprid might have a potential to use in toxic bait formulations against houseflies.

A systematic review of human pathogens carried by the housefly (Musca domestica L.)

BACKGROUND

The synanthropic house fly, Musca domestica (Diptera: Muscidae), is a mechanical vector of pathogens (bacteria, fungi, viruses, and parasites), some of which cause serious diseases in humans and domestic animals. In the present study, a systematic review was done on the types and prevalence of human pathogens carried by the house fly.

METHODS

Major health-related electronic databases including PubMed, PubMed Central, Google Scholar, and Science Direct were searched (Last update 31/11/2017) for relevant literature on pathogens that have been isolated from the house fly.

RESULTS

Of the 1718 titles produced by bibliographic search, 99 were included in the review. Among the titles included, 69, 15, 3, 4, 1 and 7 described bacterial, fungi, bacteria+fungi, parasites, parasite+bacteria, and viral pathogens, respectively. Most of the house flies were captured in/around human habitation and animal farms. Pathogens were frequently isolated from body surfaces of the flies. Over 130 pathogens, predominantly bacteria (including some serious and life-threatening species) were identified from the house flies. Numerous publications also reported antimicrobial resistant bacteria and fungi isolated from house flies.

CONCLUSIONS

This review showed that house flies carry a large number of pathogens which can cause serious infections in humans and animals. More studies are needed to identify new pathogens carried by the house fly.