Background and Aim: Staphylococcus pseudintermedius is a zoonotic bacterium commonly found in ani... more Background and Aim: Staphylococcus pseudintermedius is a zoonotic bacterium commonly found in animals, especially dogs. These bacteria can survive on environmental surfaces for several months. The infection of S. pseudintermedius from the environment is possible, but properly cleaning surface objects can prevent it. This study aimed to investigate the prevalence of methicillin-resistant S. pseudintermedius (MRSP) in the environment of a recently constructed veterinary hospital in Southern Thailand, where we hypothesized that the prevalence of MRSP might be very low. Materials and Methods: At three different time points, 150 samples were collected from different environmental surfaces and wastewater across the veterinary hospital. The collection was done after the hospital's cleaning. Bacteria were purified in the culture before being identified as species by biochemical tests and polymerase chain reaction (PCR). Next, the antimicrobial-resistant profile was performed using an automated system (Vitek 2). Finally, the antimicrobial resistance genes were identified using PCR. Results: Fifteen colonies of S. pseudintermedius were isolated from the surfaces of eight floors, four tables, two chairs, and one rebreathing tube. Fourteen colonies (93.3%) were multidrug-resistant (MDR) and carried the blaZ gene (93.3%). The majority of colonies were resistant to benzylpenicillin (93.3%), cefovecin (93.3%), ceftiofur (93.3%), kanamycin (93.3%), and neomycin (93.3%). Notably, only four colonies (26.7%) were methicillin-susceptible S. pseudintermedius, whereas 11 colonies (73.3%) were MRSP and carried both the mecA and blaZ genes. Five MRSP (45.5%) were resistant to at least 14 antimicrobial drugs, represented as extensively drug-resistant (XDR) bacteria. Ten of eleven MRSP (90.9%) were Staphylococcal chromosomal mec type V, while another displayed untypeable. Despite the routine and extensive cleaning with detergent and disinfectant, MRSP isolates were still detectable. Conclusion: Many isolates of MRSP were found in this veterinary hospital. Almost all of them were MDR, and nearly half were XDR, posing a threat to animals and humans. In addition, the current hospital cleaning procedure proved ineffective. Future research should be conducted to determine the bacterial biofilm properties and bacterial sensitivity to certain detergents and disinfectants.
Background and Aim: Mammaliicoccus sciuri, formerly known as Staphylococcus sciuri, is an opportu... more Background and Aim: Mammaliicoccus sciuri, formerly known as Staphylococcus sciuri, is an opportunistic pathogen in the environment, human and animal mucosa, and skin. Although this pathogen is becoming more resistant to drugs and harmful to animals and humans, basic knowledge of this pathogen remains limited. This study aimed to investigate a new multilocus sequencing type (MLST) related to the antibiotic resistance pattern of M. sciuri from animals in southern Thailand. Materials and Methods: We used 11 methicillin-resistant M. sciuri (MRMS) isolates in this study which were obtained from six horses, four cows, and one chicken of the previous study. Antimicrobial resistance (AMR) was re-evaluated based on the minimum inhibitory concentration using the VITEK® 2 automated system. Three AMR genes were examined, namely mecA, mecC, and blaZ. Staphylococcal chromosomal cassette mec (SCCmec) gene detection was performed through the multiplex polymerase chain reaction (PCR). Internal segm...
Background and Aim: Stomoxys and tabanid flies are of medical and veterinary importance because t... more Background and Aim: Stomoxys and tabanid flies are of medical and veterinary importance because they play crucial roles in disease transmission as mechanical vectors of various hemopathogens. However, its role as a hemoprotozoan parasite vector in horse farms has not been studied. Therefore, we investigated the occurrence of hemoprotozoan parasites belonging to the genera Babesia, Theileria, and Trypanosoma in Stomoxys and tabanid flies using conventional polymerase chain reaction (PCR) and DNA sequencing. Materials and Methods: All samples (Stomoxys and tabanid flies) were collected using an Nzi trap for three consecutive days each month from November 2022 to March 2023. The flies were morphologically identified to the species level and separated according to sex. Individual (for tabanid flies) or pooled samples (consisting of three specimens of Stomoxys flies of the same species and sex collected from the same site) were used for DNA extraction. Conventional PCR was used to screen...
Background and Aim: Blood parasite infections such as anaplasmosis, babesiosis, and ehrlichiosis ... more Background and Aim: Blood parasite infections such as anaplasmosis, babesiosis, and ehrlichiosis are commonly found in domestic dogs, which adversely influence their health. Many dogs are infected with multiple blood parasites that cause more severe diseases than a single infection. This study aimed to investigate the effect of multiple blood parasite infections on the hematological profiles of dogs at a shelter in Southern Thailand. Materials and Methods: The blood samples from 122 dogs were collected to assess the hematology profiles of uninfected, single-infected, and multiple blood parasite-infected dogs. The results were compared using Kruskal-Wallis test and Dwass-Steel-Critchlow-Fligner pairwise comparisons. The infections were confirmed by polymerase chain reaction. Results: The results showed that all the infected dogs had significantly lower red blood cell (RBC) count, hemoglobin (HB), hematocrit (HCT), and platelet count (PLT) than the uninfected dogs. Although the dogs w...
Background and Aim: Antimicrobial resistance (AMR) is a significant threat to global health and d... more Background and Aim: Antimicrobial resistance (AMR) is a significant threat to global health and development. Inappropriate antimicrobial drug use in animals cause AMR, and most studies focus on livestock because of the widespread use of antimicrobial medicines. There is a lack of studies on sports animals and AMR issues. This study aimed to characterize the AMR profile of E. coli found in sports animals (fighting cocks, fighting bulls, and sport horses) and soils from their environment. Materials and Methods: Bacterial isolation and identification were conducted to identify E. coli isolates recovered from fresh feces that were obtained from fighting cocks (n = 32), fighting bulls (n = 57), sport horses (n = 33), and soils from those farms (n = 32) at Nakhon Si Thammarat. Antimicrobial resistance was determined using 15 tested antimicrobial agents - ampicillin (AM), amoxicillin-clavulanic acid, cephalexin (CN), cefalotin (CF), cefoperazone, ceftiofur, cefquinome, gentamicin, neomycin...
Background and Aim: Female tabanids play a key role in disease transmission as mechanical vectors... more Background and Aim: Female tabanids play a key role in disease transmission as mechanical vectors for various hemopathogens, but only a limited number of studies have been conducted on them. This study aimed to investigate the occurrence of hemopathogens in tabanid flies compared to those found in nearby cattle hosts. Materials and Methods: Tabanids were collected using a Nzi trap for three consecutive days per month during the dry season (February–May 2021). Furthermore, blood samples were collected from 20 beef cattle (Bos taurus) raised in the same area where the flies were captured. Conventional polymerase chain reaction (PCR) was used to detect hemopathogenic DNA in flies and beef cattle. Results: In total, 279 female tabanids belonging to five species were collected: Tabanus megalops, Tabanus rubidus, Tabanus mesogaeus, Chrysops dispar, and Chrysops fuscomarginalis. Notably, T. megalops was the most abundant species, accounting for 89.2% of the flies collected (n = 249). PCR t...
<p>Geographic locations of the sampled areas and number of specimens for wing morphometric ... more <p>Geographic locations of the sampled areas and number of specimens for wing morphometric and for cytochrome b gene analyses.</p
<p>Mean time (days; n = 3 replicates) for <i>C</i>. <i>vicina</i> t... more <p>Mean time (days; n = 3 replicates) for <i>C</i>. <i>vicina</i> to reach the post-feeding, puparial, and adult stages.</p
<p>The evolutionary history was inferred by using the maximum likelihood method based on th... more <p>The evolutionary history was inferred by using the maximum likelihood method based on the Tamura 3-parameter model [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0207188#pone.0207188.ref037" target="_blank">37</a>]. There were a total of 528 positions in the final dataset. Evolutionary analyses were conducted in MEGA6 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0207188#pone.0207188.ref036" target="_blank">36</a>]. The symbol ○ indicates <i>C</i>. <i>vicina</i> samples from Germany, ● indicates <i>C</i>. <i>vicina</i> samples from England, and θ indicates outgroups.</p
Mosquitoes are hematophagous insects that transmit parasites and pathogens with devastating effec... more Mosquitoes are hematophagous insects that transmit parasites and pathogens with devastating effects on humans, particularly in subtropical regions. Different mosquito species display various behaviors, breeding sites, and geographic distribution; however, they can be difficult to distinguish in the field due to morphological similarities between species and damage caused during trapping and transportation. Vector control methods for controlling mosquito-borne disease epidemics require an understanding of which vector species are present in the area as well as the epidemiological patterns of disease transmission. Although molecular techniques can accurately distinguish between mosquito species, they are costly and laborious, making them unsuitable for extensive use in the field. Thus, alternative techniques are required. Geometric morphometrics (GM) is a rapid and inexpensive technique that can be used to analyze the size, shape, and shape variation of individuals based on a range of...
Many muscid flies (Diptera: Muscidae) are well-known as medical, veterinary, and forensically sig... more Many muscid flies (Diptera: Muscidae) are well-known as medical, veterinary, and forensically significant insects, thus correct species identification is critically important before applying for fly control and determining a minimal post-mortem interval (PMImin) in forensic investigations. Limited in taxonomic keys and taxonomists, as well as scanty in advanced molecular laboratories lead to difficulty in identification of muscids. To date, a landmark-based geometric morphometric analysis of wings has proven to be a promising alternative technique for identifying many insect species. Herein, we assessed wing morphometric analysis for identification of 6 medically and forensically important muscids, namely Musca domestica Linnaeus, Musca pattoni Austen, Musca ventrosa Wiedemann, Hydrotaea chalcogaster (Wiedemann), Hydrotaea spinigera Stein and Dichaetomyia quadrata (Wiedemann). A total of 302 right wing images were digitized based on 15 homologous landmarks and wing shape variation among genera and species was analyzed using canonical variate analysis, whereas sexual shape dimorphism of M. domestica, M. ventrosa and D. quadrata was analyzed using discriminant function analysis. The cross-validation revealed a relatively high percentage of correct classification in most species, ranging from 86.4% to 100%, except for M. pattoni, being 67.5%. Misidentifications were mainly due to cross-pairings of the genus Musca; M. domestica VS M. pattoni VS M. ventrosa. The accuracy of classification using cross-validation test demonstrated that wing shape can be used to evaluate muscids flies at the genus- and species-level, and separate sexes of the three species analyzed, with a high reliability. This study sheds light on genus, species and sex discrimination of six muscid species that have been approached using wing morphometric analysis.
Although myiasis caused by the blow fly, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae), ... more Although myiasis caused by the blow fly, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae), has been reported in Thailand, all of the cases were human. This study described three cutaneous myiasis cases caused by C. bezziana in dogs in Chiang Mai province, northern Thailand. The removal of fly larvae together with specific treatment to cure all cases in this study was represented.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Effective control of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae), a blow fly species... more Effective control of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae), a blow fly species of medical and forensic importance, requires information on seasonal prevalence and bionomics. Therefore, daily and seasonal activity patterns of C. rufifacies were studied in 3 locations representing different microhabitats (palm plantation, forested area, longan orchard) in a suburban area of Chiang Mai Province, northern Thailand. Investigations were conducted hourly for 24 h using a semi-automatic trap baited with 1-d-old beef offal (300 g). Collections were carried out twice per mo from Jul 2013 to Jun 2014. A total of 55,966 adult C. rufifacies were collected, with 52.4% of individuals trapped in the forested area. Chrysomya rufifacies was present in collections throughout the yr with peak abundance in summer. This species was active during the d with peak activity in late afternoon (3:00 to 6:00 PM). Fly abundance in traps was positively correlated with temperature (r = 0.391; P < 0.001) but negatively correlated with relative humidity (r = −0.388; P < 0.001). Female flies were more abundant in collections (0.26 male per female sex ratio), with 80% of individuals being nongravid. The baseline information provided by our study suggests that C. rufifacies is well-adapted to variable climatic conditions present in northern Thailand, specifically suburban Chiang Mai Province.
Flesh flies are insects of forensic importance as the larvae associated with human remains can be... more Flesh flies are insects of forensic importance as the larvae associated with human remains can be used to estimate a minimum post-mortem interval (PMI min) in most cases. And, because life-history traits can vary across species, correct identification is a mandatory step before being used as evidence. Adult flesh flies are extremely similar in general appearance, which causes difficulty in species identification as it is largely based on the morphology of the male genitalia; this also makes it difficult to identify females. Currently, landmark-based geometric morphometric analysis of insect wings has proven to be a valuable tool for species identification. Herein, we applied wing morphometric analysis of 524 flesh fly specimens comprising 12 species from Thailand. The right wing of each specimen was removed, mounted on a microscope slide, photographed, and digitized using 18 landmarks. Wing shape variation among genera and species were analyzed using canonical variate analysis, while wing shape variation between sexes of each species was analyzed using discriminant function analysis. A cross-validation test was used to evaluate the reliability of classification. Results of this study demonstrate wing shape can be used to separate genera and species, and distinguish between sexes of the same species, with high reliability. Therefore, the landmark-based geometric morphometric analysis of wings is a useful additional method for species and sex discrimination of flesh flies.
The bluebottle blow fly Calliphora vicina is a common species distributed throughout Europe that ... more The bluebottle blow fly Calliphora vicina is a common species distributed throughout Europe that can play an important role as forensic evidence in crime investigations. Developmental rates of C. vicina from distinct populations from Germany and England were compared under different temperature regimes to explore the use of growth data from different geographical regions for local case work. Wing morphometrics and molecular analysis between these populations were also studied as indicators for biological differences. One colony each of German and English C. vicina were cultured at the Institute of Legal Medicine in Frankfurt, Germany. Three different temperature regimes were applied, two constant (16˚C & 25˚C) and one variable (17-26˚C, room temperature = RT). At seven time points (600, 850, 1200, 1450, 1800, 2050, and 2400 accumulated degree hours), larval lengths were measured; additionally, the durations of the post feeding stage and intrapuparial metamorphosis were recorded. For the morphometric and molecular study, 184 females and 133 males from each C. vicina population (Germany n = 3, England n = 4) were sampled. Right wings were measured based on 19 landmarks and analyzed using canonical variates analysis and discriminant function analysis. DNA was isolated from three legs per specimen (n = 61) using 5% chelex. A 784 bp long fragment of the mitochondrial cytochrome b gene was sequenced; sequences were aligned and phylogenetically analyzed. Similar larval growth rates of C. vicina were found from different geographic populations at different temperatures during the major part of development. Nevertheless, because minor differences were found a wider range of temperatures and sampling more time points should be analyzed to obtain more information relevant for forensic case work. Wing shape variation showed a difference between the German and English populations (P<0.0001). However, separation between the seven German and English populations at the smaller geographic scale remained ambiguous. Molecular phylogenetic analysis by maximum likelihood method could not
Male genitalia of blow flies (Diptera: Calliphoridae) are distinctive in their morphological feat... more Male genitalia of blow flies (Diptera: Calliphoridae) are distinctive in their morphological features and are often used for species identification. The aim of this work was to investigate the male genitalia of blow flies of medical and forensic importance from Thailand at the ultrastructural level, using scanning electron microscopy (SEM). Flies in two subfamilies were examined: Chrysomyinae [Chrysomya bezziana Villeneuve, Chrysomya chani Kurahashi, Chrysomya nigripes Aubertin, Chrysomya pinguis (Walker), Chrysomya rufifacies (Macquart), Chrysomya thanomthini Kurahashi & Tumrasvin, and Chrysomya villeneuvi Patton] and Luciliinae [Hemipyrellia ligurriens (Wiedemann), Hypopygiopsis infumata (Bigot), Hypopygiopsis tumrasvini Kurahashi, Lucilia cuprina (Wiedemann), Lucilia papuensis Macquart, Lucilia porphyrina (Walker), and Lucilia sinensis Aubertin]. Particular attention was paid to the main distinguishing features such as the shapes of the cercus and the surstylus, and the complex structure of the distiphallus. The differentiation of the male genitalia of these species at the SEM level is discussed and compared to the conditions in closely related species such as Chrysomya megacephala (Fabricius). A key for the identification of 14 blow fly species based on male genitalia is provided.
Background and Aim: Staphylococcus pseudintermedius is a zoonotic bacterium commonly found in ani... more Background and Aim: Staphylococcus pseudintermedius is a zoonotic bacterium commonly found in animals, especially dogs. These bacteria can survive on environmental surfaces for several months. The infection of S. pseudintermedius from the environment is possible, but properly cleaning surface objects can prevent it. This study aimed to investigate the prevalence of methicillin-resistant S. pseudintermedius (MRSP) in the environment of a recently constructed veterinary hospital in Southern Thailand, where we hypothesized that the prevalence of MRSP might be very low. Materials and Methods: At three different time points, 150 samples were collected from different environmental surfaces and wastewater across the veterinary hospital. The collection was done after the hospital's cleaning. Bacteria were purified in the culture before being identified as species by biochemical tests and polymerase chain reaction (PCR). Next, the antimicrobial-resistant profile was performed using an automated system (Vitek 2). Finally, the antimicrobial resistance genes were identified using PCR. Results: Fifteen colonies of S. pseudintermedius were isolated from the surfaces of eight floors, four tables, two chairs, and one rebreathing tube. Fourteen colonies (93.3%) were multidrug-resistant (MDR) and carried the blaZ gene (93.3%). The majority of colonies were resistant to benzylpenicillin (93.3%), cefovecin (93.3%), ceftiofur (93.3%), kanamycin (93.3%), and neomycin (93.3%). Notably, only four colonies (26.7%) were methicillin-susceptible S. pseudintermedius, whereas 11 colonies (73.3%) were MRSP and carried both the mecA and blaZ genes. Five MRSP (45.5%) were resistant to at least 14 antimicrobial drugs, represented as extensively drug-resistant (XDR) bacteria. Ten of eleven MRSP (90.9%) were Staphylococcal chromosomal mec type V, while another displayed untypeable. Despite the routine and extensive cleaning with detergent and disinfectant, MRSP isolates were still detectable. Conclusion: Many isolates of MRSP were found in this veterinary hospital. Almost all of them were MDR, and nearly half were XDR, posing a threat to animals and humans. In addition, the current hospital cleaning procedure proved ineffective. Future research should be conducted to determine the bacterial biofilm properties and bacterial sensitivity to certain detergents and disinfectants.
Background and Aim: Mammaliicoccus sciuri, formerly known as Staphylococcus sciuri, is an opportu... more Background and Aim: Mammaliicoccus sciuri, formerly known as Staphylococcus sciuri, is an opportunistic pathogen in the environment, human and animal mucosa, and skin. Although this pathogen is becoming more resistant to drugs and harmful to animals and humans, basic knowledge of this pathogen remains limited. This study aimed to investigate a new multilocus sequencing type (MLST) related to the antibiotic resistance pattern of M. sciuri from animals in southern Thailand. Materials and Methods: We used 11 methicillin-resistant M. sciuri (MRMS) isolates in this study which were obtained from six horses, four cows, and one chicken of the previous study. Antimicrobial resistance (AMR) was re-evaluated based on the minimum inhibitory concentration using the VITEK® 2 automated system. Three AMR genes were examined, namely mecA, mecC, and blaZ. Staphylococcal chromosomal cassette mec (SCCmec) gene detection was performed through the multiplex polymerase chain reaction (PCR). Internal segm...
Background and Aim: Stomoxys and tabanid flies are of medical and veterinary importance because t... more Background and Aim: Stomoxys and tabanid flies are of medical and veterinary importance because they play crucial roles in disease transmission as mechanical vectors of various hemopathogens. However, its role as a hemoprotozoan parasite vector in horse farms has not been studied. Therefore, we investigated the occurrence of hemoprotozoan parasites belonging to the genera Babesia, Theileria, and Trypanosoma in Stomoxys and tabanid flies using conventional polymerase chain reaction (PCR) and DNA sequencing. Materials and Methods: All samples (Stomoxys and tabanid flies) were collected using an Nzi trap for three consecutive days each month from November 2022 to March 2023. The flies were morphologically identified to the species level and separated according to sex. Individual (for tabanid flies) or pooled samples (consisting of three specimens of Stomoxys flies of the same species and sex collected from the same site) were used for DNA extraction. Conventional PCR was used to screen...
Background and Aim: Blood parasite infections such as anaplasmosis, babesiosis, and ehrlichiosis ... more Background and Aim: Blood parasite infections such as anaplasmosis, babesiosis, and ehrlichiosis are commonly found in domestic dogs, which adversely influence their health. Many dogs are infected with multiple blood parasites that cause more severe diseases than a single infection. This study aimed to investigate the effect of multiple blood parasite infections on the hematological profiles of dogs at a shelter in Southern Thailand. Materials and Methods: The blood samples from 122 dogs were collected to assess the hematology profiles of uninfected, single-infected, and multiple blood parasite-infected dogs. The results were compared using Kruskal-Wallis test and Dwass-Steel-Critchlow-Fligner pairwise comparisons. The infections were confirmed by polymerase chain reaction. Results: The results showed that all the infected dogs had significantly lower red blood cell (RBC) count, hemoglobin (HB), hematocrit (HCT), and platelet count (PLT) than the uninfected dogs. Although the dogs w...
Background and Aim: Antimicrobial resistance (AMR) is a significant threat to global health and d... more Background and Aim: Antimicrobial resistance (AMR) is a significant threat to global health and development. Inappropriate antimicrobial drug use in animals cause AMR, and most studies focus on livestock because of the widespread use of antimicrobial medicines. There is a lack of studies on sports animals and AMR issues. This study aimed to characterize the AMR profile of E. coli found in sports animals (fighting cocks, fighting bulls, and sport horses) and soils from their environment. Materials and Methods: Bacterial isolation and identification were conducted to identify E. coli isolates recovered from fresh feces that were obtained from fighting cocks (n = 32), fighting bulls (n = 57), sport horses (n = 33), and soils from those farms (n = 32) at Nakhon Si Thammarat. Antimicrobial resistance was determined using 15 tested antimicrobial agents - ampicillin (AM), amoxicillin-clavulanic acid, cephalexin (CN), cefalotin (CF), cefoperazone, ceftiofur, cefquinome, gentamicin, neomycin...
Background and Aim: Female tabanids play a key role in disease transmission as mechanical vectors... more Background and Aim: Female tabanids play a key role in disease transmission as mechanical vectors for various hemopathogens, but only a limited number of studies have been conducted on them. This study aimed to investigate the occurrence of hemopathogens in tabanid flies compared to those found in nearby cattle hosts. Materials and Methods: Tabanids were collected using a Nzi trap for three consecutive days per month during the dry season (February–May 2021). Furthermore, blood samples were collected from 20 beef cattle (Bos taurus) raised in the same area where the flies were captured. Conventional polymerase chain reaction (PCR) was used to detect hemopathogenic DNA in flies and beef cattle. Results: In total, 279 female tabanids belonging to five species were collected: Tabanus megalops, Tabanus rubidus, Tabanus mesogaeus, Chrysops dispar, and Chrysops fuscomarginalis. Notably, T. megalops was the most abundant species, accounting for 89.2% of the flies collected (n = 249). PCR t...
<p>Geographic locations of the sampled areas and number of specimens for wing morphometric ... more <p>Geographic locations of the sampled areas and number of specimens for wing morphometric and for cytochrome b gene analyses.</p
<p>Mean time (days; n = 3 replicates) for <i>C</i>. <i>vicina</i> t... more <p>Mean time (days; n = 3 replicates) for <i>C</i>. <i>vicina</i> to reach the post-feeding, puparial, and adult stages.</p
<p>The evolutionary history was inferred by using the maximum likelihood method based on th... more <p>The evolutionary history was inferred by using the maximum likelihood method based on the Tamura 3-parameter model [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0207188#pone.0207188.ref037" target="_blank">37</a>]. There were a total of 528 positions in the final dataset. Evolutionary analyses were conducted in MEGA6 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0207188#pone.0207188.ref036" target="_blank">36</a>]. The symbol ○ indicates <i>C</i>. <i>vicina</i> samples from Germany, ● indicates <i>C</i>. <i>vicina</i> samples from England, and θ indicates outgroups.</p
Mosquitoes are hematophagous insects that transmit parasites and pathogens with devastating effec... more Mosquitoes are hematophagous insects that transmit parasites and pathogens with devastating effects on humans, particularly in subtropical regions. Different mosquito species display various behaviors, breeding sites, and geographic distribution; however, they can be difficult to distinguish in the field due to morphological similarities between species and damage caused during trapping and transportation. Vector control methods for controlling mosquito-borne disease epidemics require an understanding of which vector species are present in the area as well as the epidemiological patterns of disease transmission. Although molecular techniques can accurately distinguish between mosquito species, they are costly and laborious, making them unsuitable for extensive use in the field. Thus, alternative techniques are required. Geometric morphometrics (GM) is a rapid and inexpensive technique that can be used to analyze the size, shape, and shape variation of individuals based on a range of...
Many muscid flies (Diptera: Muscidae) are well-known as medical, veterinary, and forensically sig... more Many muscid flies (Diptera: Muscidae) are well-known as medical, veterinary, and forensically significant insects, thus correct species identification is critically important before applying for fly control and determining a minimal post-mortem interval (PMImin) in forensic investigations. Limited in taxonomic keys and taxonomists, as well as scanty in advanced molecular laboratories lead to difficulty in identification of muscids. To date, a landmark-based geometric morphometric analysis of wings has proven to be a promising alternative technique for identifying many insect species. Herein, we assessed wing morphometric analysis for identification of 6 medically and forensically important muscids, namely Musca domestica Linnaeus, Musca pattoni Austen, Musca ventrosa Wiedemann, Hydrotaea chalcogaster (Wiedemann), Hydrotaea spinigera Stein and Dichaetomyia quadrata (Wiedemann). A total of 302 right wing images were digitized based on 15 homologous landmarks and wing shape variation among genera and species was analyzed using canonical variate analysis, whereas sexual shape dimorphism of M. domestica, M. ventrosa and D. quadrata was analyzed using discriminant function analysis. The cross-validation revealed a relatively high percentage of correct classification in most species, ranging from 86.4% to 100%, except for M. pattoni, being 67.5%. Misidentifications were mainly due to cross-pairings of the genus Musca; M. domestica VS M. pattoni VS M. ventrosa. The accuracy of classification using cross-validation test demonstrated that wing shape can be used to evaluate muscids flies at the genus- and species-level, and separate sexes of the three species analyzed, with a high reliability. This study sheds light on genus, species and sex discrimination of six muscid species that have been approached using wing morphometric analysis.
Although myiasis caused by the blow fly, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae), ... more Although myiasis caused by the blow fly, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae), has been reported in Thailand, all of the cases were human. This study described three cutaneous myiasis cases caused by C. bezziana in dogs in Chiang Mai province, northern Thailand. The removal of fly larvae together with specific treatment to cure all cases in this study was represented.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Effective control of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae), a blow fly species... more Effective control of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae), a blow fly species of medical and forensic importance, requires information on seasonal prevalence and bionomics. Therefore, daily and seasonal activity patterns of C. rufifacies were studied in 3 locations representing different microhabitats (palm plantation, forested area, longan orchard) in a suburban area of Chiang Mai Province, northern Thailand. Investigations were conducted hourly for 24 h using a semi-automatic trap baited with 1-d-old beef offal (300 g). Collections were carried out twice per mo from Jul 2013 to Jun 2014. A total of 55,966 adult C. rufifacies were collected, with 52.4% of individuals trapped in the forested area. Chrysomya rufifacies was present in collections throughout the yr with peak abundance in summer. This species was active during the d with peak activity in late afternoon (3:00 to 6:00 PM). Fly abundance in traps was positively correlated with temperature (r = 0.391; P < 0.001) but negatively correlated with relative humidity (r = −0.388; P < 0.001). Female flies were more abundant in collections (0.26 male per female sex ratio), with 80% of individuals being nongravid. The baseline information provided by our study suggests that C. rufifacies is well-adapted to variable climatic conditions present in northern Thailand, specifically suburban Chiang Mai Province.
Flesh flies are insects of forensic importance as the larvae associated with human remains can be... more Flesh flies are insects of forensic importance as the larvae associated with human remains can be used to estimate a minimum post-mortem interval (PMI min) in most cases. And, because life-history traits can vary across species, correct identification is a mandatory step before being used as evidence. Adult flesh flies are extremely similar in general appearance, which causes difficulty in species identification as it is largely based on the morphology of the male genitalia; this also makes it difficult to identify females. Currently, landmark-based geometric morphometric analysis of insect wings has proven to be a valuable tool for species identification. Herein, we applied wing morphometric analysis of 524 flesh fly specimens comprising 12 species from Thailand. The right wing of each specimen was removed, mounted on a microscope slide, photographed, and digitized using 18 landmarks. Wing shape variation among genera and species were analyzed using canonical variate analysis, while wing shape variation between sexes of each species was analyzed using discriminant function analysis. A cross-validation test was used to evaluate the reliability of classification. Results of this study demonstrate wing shape can be used to separate genera and species, and distinguish between sexes of the same species, with high reliability. Therefore, the landmark-based geometric morphometric analysis of wings is a useful additional method for species and sex discrimination of flesh flies.
The bluebottle blow fly Calliphora vicina is a common species distributed throughout Europe that ... more The bluebottle blow fly Calliphora vicina is a common species distributed throughout Europe that can play an important role as forensic evidence in crime investigations. Developmental rates of C. vicina from distinct populations from Germany and England were compared under different temperature regimes to explore the use of growth data from different geographical regions for local case work. Wing morphometrics and molecular analysis between these populations were also studied as indicators for biological differences. One colony each of German and English C. vicina were cultured at the Institute of Legal Medicine in Frankfurt, Germany. Three different temperature regimes were applied, two constant (16˚C & 25˚C) and one variable (17-26˚C, room temperature = RT). At seven time points (600, 850, 1200, 1450, 1800, 2050, and 2400 accumulated degree hours), larval lengths were measured; additionally, the durations of the post feeding stage and intrapuparial metamorphosis were recorded. For the morphometric and molecular study, 184 females and 133 males from each C. vicina population (Germany n = 3, England n = 4) were sampled. Right wings were measured based on 19 landmarks and analyzed using canonical variates analysis and discriminant function analysis. DNA was isolated from three legs per specimen (n = 61) using 5% chelex. A 784 bp long fragment of the mitochondrial cytochrome b gene was sequenced; sequences were aligned and phylogenetically analyzed. Similar larval growth rates of C. vicina were found from different geographic populations at different temperatures during the major part of development. Nevertheless, because minor differences were found a wider range of temperatures and sampling more time points should be analyzed to obtain more information relevant for forensic case work. Wing shape variation showed a difference between the German and English populations (P<0.0001). However, separation between the seven German and English populations at the smaller geographic scale remained ambiguous. Molecular phylogenetic analysis by maximum likelihood method could not
Male genitalia of blow flies (Diptera: Calliphoridae) are distinctive in their morphological feat... more Male genitalia of blow flies (Diptera: Calliphoridae) are distinctive in their morphological features and are often used for species identification. The aim of this work was to investigate the male genitalia of blow flies of medical and forensic importance from Thailand at the ultrastructural level, using scanning electron microscopy (SEM). Flies in two subfamilies were examined: Chrysomyinae [Chrysomya bezziana Villeneuve, Chrysomya chani Kurahashi, Chrysomya nigripes Aubertin, Chrysomya pinguis (Walker), Chrysomya rufifacies (Macquart), Chrysomya thanomthini Kurahashi & Tumrasvin, and Chrysomya villeneuvi Patton] and Luciliinae [Hemipyrellia ligurriens (Wiedemann), Hypopygiopsis infumata (Bigot), Hypopygiopsis tumrasvini Kurahashi, Lucilia cuprina (Wiedemann), Lucilia papuensis Macquart, Lucilia porphyrina (Walker), and Lucilia sinensis Aubertin]. Particular attention was paid to the main distinguishing features such as the shapes of the cercus and the surstylus, and the complex structure of the distiphallus. The differentiation of the male genitalia of these species at the SEM level is discussed and compared to the conditions in closely related species such as Chrysomya megacephala (Fabricius). A key for the identification of 14 blow fly species based on male genitalia is provided.
Uploads
Papers by Narin Sontigun