Showing papers on "Lucilia cuprina published in 2012"

Prevalence and relative risk of Cronobacter spp., Salmonella spp., and Listeria monocytogenes associated with the body surfaces and guts of individual filth flies.

Abstract: Although flies are important vectors of food-borne pathogens, there is little information to accurately assess the food-related health risk of the presence of individual flies, especially in urban areas. This study quantifies the prevalence and the relative risk of food-borne pathogens associated with the body surfaces and guts of individual wild flies. One hundred flies were collected from the dumpsters of 10 randomly selected urban restaurants. Flies were identified using taxonomic keys before being individually dissected. Cronobacter spp., Salmonella spp., and Listeria monocytogenes were detected using the PCR-based BAX system Q7. Positive samples were confirmed by culture on specific media and through PCR amplification and sequencing or ribotyping. Among collected flies were the housefly, Musca domestica (47%), the blowflies, Lucilia cuprina (33%) and Lucilia sericata (14%), and others (6%). Cronobacter species were detected in 14% of flies, including C. sakazakii, C. turicensis, and C. universalis, leading to the proposal of flies as a natural reservoir of this food-borne pathogen. Six percent of flies carried Salmonella enterica, including the serovars Poona, Hadar, Schwarzengrund, Senftenberg, and Brackenridge. L. monocytogenes was detected in 3% of flies. Overall, the prevalence of food-borne pathogens was three times greater in the guts than on the body surfaces of the flies. The relative risk of flies carrying any of the three pathogens was associated with the type of pathogen, the body part of the fly, and the ambient temperature. These data enhance the ability to predict the microbiological risk associated with the presence of individual flies in food and food facilities.

Organization and expression of the Australian sheep blowfly (Lucilia cuprina) hsp23, hsp24, hsp70 and hsp83 genes

Abstract: In this study we report the isolation and characterization of a heat shock protein 70 (hsp70) gene, the hsp83 gene and two genes that encode small Hsps (Lchsp23 and Lchsp24) from the Australian sheep blowfly, Lucilia cuprina, a major agricultural pest. Phylogenetic analyses indicate that the LcHsp23 protein is the orthologue of Drosophila melanogaster Hsp23 and LcHsp24 is the orthologue of Sarcophaga crassipalpis Hsp23. Quantitative reverse-transcriptase PCR analysis showed that the basal level of Lchsp83 RNA is relatively high at all developmental stages and only moderately induced by heat shock. In contrast, Lchsp70 transcripts are present at low levels and strongly induced by heat shock at all stages. The basal levels of expression and degrees of heat induction of the Lchsp23 and Lchsp24 transcripts were more variable across the different developmental stages. Putative heat shock factor binding sites were identified in the Lchsp24, Lchsp70 and Lchsp83 gene promoters. The isolation of these hsp gene promoters will facilitate constitutive or conditional expression of a gene of interest in transgenic Lucilia.

Cyromazine resistance detected in Australian sheep blowfly.

Abstract: Objective To investigate the cause of cyromazine failure to protect lambs from flystrike. Methods Lucilia cuprina larvae from a Nimmitabel (New South Wales) population associated with failure of a cyromazine spray-on to protect lambs from flystrike were compared with larvae from a susceptible field strain and a reference susceptible laboratory strain in laboratory bioassays. Batches of neonate blowfly larvae were transferred onto homogenised bovine liver containing varying concentrations of cyromazine or dicyclanil and the numbers of larvae pupating and completing development were recorded. Results Based on the ability of larvae to complete development on liver homogenate containing 1 mg/kg cyromazine, the phenotypic frequency of resistance in the Nimmitabel population was estimated to be approximately 4%. Compared with a susceptible field strain, the Nimmitabel population was 3-fold more resistant to cyromazine and twice as resistant to dicyclanil at the LC95 level (lethal concentration killing 95% of larvae). In the laboratory, the Nimmitabel strain responded to sequential exposure of larvae to food containing cyromazine by becoming more resistant. Resistance to cyromazine was incompletely dominant, giving resistant larvae a survival advantage over susceptible types over a relatively narrow range of cyromazine concentrations. Conclusion Cyromazine resistance was detected in a field population of L. cuprina. Low-level cross-resistance to dicyclanil was also confirmed. Until more is known about the resistance, the prudent recommendation to control flystrike by this blowfly population is topical treatment with ivermectin.

Observations on morphology of immature Lucilia porphyrina (Diptera: Calliphoridae), a fly species of forensic importance.

Abstract: Lucilia porphyrina (Walker) is a blow fly of forensic importance, and shares its geographical distribution with a related forensically important species, Lucilia cuprina (Wiedemann). The immature stages of both species are similar in general appearance; therefore, correct identification should be given special consideration. This study highlighted the main features of L. porphyrina larvae, as observed under light microscopy and scanning electron microscopy. Particular attention is given to the anterior and posterior spiracles, cephalopharyngeal skeleton, and characteristics of the dorsal spines between the prothorax and mesothorax. In the third instar specifically, morphological information on L. porphyrina showed several features that are shared by L. cuprina, and therefore need certain identification to distinguish between them. Such key features are (1) greater posterior spiracle, (2) apparent inner projection between the middle and lower slits of the posterior spiracle, and (3) strongly sclerotized peritreme. The number of papillae on the anterior spiracle may be a supplement, five to nine and three to six in L. porphyrina and L. cuprina, respectively. The key for identifying third instar of forensically important flies in Thailand has been updated to include L. porphyrina.

Cutaneous Myiasis: Is Lucilia cuprina Safe and Acceptable for Maggot Debridement Therapy?

Abstract: Preservation of viable tissue is important in wound management. It is achieved by small, incremental removal of devitalised, necrotic and infected tissues. Maggot debridement therapy (MDT) is used in septic necrotic wounds that fail to respond to conventional modalities. MDT has relied on Lucilia cuprina, which consumes only necrotic tissues, as opposed to Lucilia cuprina, which devours both flesh and necrotic tissues. Recent findings have shown that L. cuprina consumes mainly necrotic and very small amounts of viable tissues and may be used in MDT where L. sericata is very rare or absent. Here we describe wound healing in a patient from rural South Africa with cutaneous myiasis. Our findings agree with workers who indicated that L. cuprina could be used in MDT.

Cytochrome oxidase II gene "short fragment" applicability in identification of forensically important insects

Abstract: Correct insect identification is an important issue in the forensic entomological analysis. Short DNA segments can be used to uniquely identify species. In order to be useful as a forensic tool, a short DNA sequence must be not only easily sequenced, but also contains enough variation to generate unique identifiers at either the species or population levels. In the present study, we assessed the applicability of a 189-bp mitochondrial cytochrome oxidase subunit II (COII) gene fragment in identification. We analyzed 53 specimens representing 14 species belong to Sarcophagidae (Sarcophaga carnaria, Sarcophaga dux, Sarcophaga albiceps, Helicophagella melanura, Phallosphaera gravelyi, Boettcherisca peregrina and Wohlfahrtia nuba), Calliphoridae (Lucilia cuprina, Lucilia sericate, Chrysomya megacephala, Chrysomya rufifacie and Chrysomya albiceps) and Muscidae (Musca domestica and Musca autumnalis). This region was amplified using polymerase chain reaction (PCR) followed by direct sequencing of the amplification products. Nucleotide sequence divergences were calculated using the Kimura two- parameter (K2P) distance model and a neighbour-joining (NJ) phylogenetic tree generated. No intraspecific variation within same species (0%), while interspecific variation ranged from 2% to 25%. All specimens were properly assigned into correct species apart from H. melanura and M. autumalis. Although molecular methods are very useful to identify forensically important insect, we propose to use it only in addition to the conventional methods.

Structure and ultrastructure of spermatozoa and spermiogenesis in three species of Lucilia Robineau-desvoidy, 1830 (Diptera: Calliphoridae)

Abstract: Morphology of male internal reproductive organs, spermatozoa, and spermiogenesis of the blow-flies Lucilia cuprina, Lucilia eximia, and Lucilia peruviana is first described here, using light and transmission electron microscopy. Spermiogenesis follows the characteristics described for others insect species. The spermatozoa of L. cuprina are similar to those described for other Brachycera. However, in L. eximia and L. peruviana, some differences were found. In L. cuprina and L. eximia species, the spermatozoa are long and thin, measuring about 211 μm and 146 μm in length, of which the head region measures approximately 19 μm and 17 μm, respectively. A polymorphism was observed in L. cuprina and L. eximia spermatozoa. In all three species, the head includes a monolayered acrosome with electron-lucent material. The shape of the nucleus, in cross sections, varies from circular to oval with completely condensed chromatin. Implantation of the axoneme was observed in the middle region of the nucleus, known as the “peg” region. In the next region, the beginning of two mitochondrial derivatives of similar diameter and different lengths in L. cuprina and only one in L. eximia and L. peruviana was observed. In the overlap region, the following structures were observed: nucleus, centriolar adjunct, mitochondrial derivatives, and axoneme. The axoneme is of a conventional insectan type with a 9 + 9 + 2 microtubular arrangement. The male internal reproductive tract consists of testis, deferent ducts, a strongly developed seminal vesicle, accessory glands, and ejaculatory duct. These features are consistent with the structural diversity of the dipteran reproductive tract and spermatozoa, comprising an essential tool for understanding the complex variations found in the Diptera. J. Morphol. 2011. © 2011 Wiley Periodicals, Inc.

Survival over winter and spring emergence of Lucilia cuprina (Diptera: Calliphoridae) in south-eastern Australia

Abstract: Overwintering of larvae of the Australian sheep blowfly, Lucilia cuprina (Wiedemann), was studied over 2 years in south-eastern Australia. There was a biphasic pattern of emergence of flies from larvae entering the ground during April. Some larvae deposited in April developed immediately and emerged in late autumn, whereas others entered a state of arrested development and resumed development the following spring. Overwintering mortality was generally high, but varied between years and between replicate cohorts deposited at the same time. Overwintering larvae resumed development in early to mid-September, coinciding with an increase in soil temperatures of 1.5°C over a 4-day period and soil temperatures remaining above 11°C for at least 7 consecutive days. Spring emergence of the first generation of flies after winter was synchronous from larvae deposited at different times. The first flies were detected on 2 October and 26 September in consecutive years and emergence continued for up to 50 days. Free-ranging flies were first caught in traps on 17 and 7 October in consecutive years, and numbers showed a large peak in late November and a smaller one in early March. No flies were caught from May to September. More detailed studies on the immature stages of L. cuprina, such as the conditions that induce and terminate arrested development of post-feeding larvae, and those that determine the survival of larvae and pupae in the soil, are needed. This knowledge could be used to refine control programs based on the treatment of sheep with long-acting insecticide in September or October (‘early season treatment’), which aims to prevent propagation of fly numbers from the first generation of flies and thus reduce the prevalence of fly-strike on sheep farms.

[Sequencing of mitochondrial DNA CO II gene in carrion-breeding flies and larvae in Zhengzhou].

Abstract: OBJECTIVE Using CO II sequences to identify common species of carrion-breeding flies and larvae. METHODS flies and larvae were collected on the corpses of rats in Zhengzhou district, DNA was extracted, CO II sequences were amplified and sequenced. Clustalx and MEGA 4.0 software were used to analyze the gene sequences and to construct the phylogenetic trees. RESULTS There was no significant gene difference between adults and larvae. COII gene sequences could be used to identify Boettcherisca peregrina, Aldrichina grahami and Lucilia illustris but they could not distinguish Lucilia cuprina from the Lucilia sericata because of their close evolutionary distance and single nucleotide polymorphisms in aldrichina grahami and Lucilia illustris populations were found. CONCLUSION CO II sequence of mtDNA in Zhengzhou district can be used effectively to identify some common species of carrion-breeding fly. The method is simple and accurate.

Frequency‐dependent and density‐dependent larval competition between life‐history strains of a fly, Lucilia cuprina

Abstract: 1. Competition was created between the larvae of two life-history strains of the blowfly Lucilia cuprina (Wiedemann) that have different requirements for larval resource acquisition. Adult females of one strain had the ability to mature eggs in the absence of adult feeding (autogeny) whereas the other strain lacked this ability. Autogeny shifts the burden of resource acquisition from adults to larvae, potentially leading to greater competition at this earlier life history stage. 2. A replacement series was used to determine the per-capita competitive effect between strains relative to the intra-strain effect, and density- and frequency-dependent variation in this per-capita effect was then evaluated. Evidence was found of competitive superiority of autogenous larvae when they occurred at a low frequency and low density, but their competitive ability was lost or reversed at higher frequencies and densities. 3. A dynamic competitive environment created by frequency and density dependence can account for the maintenance of genetic diversity for major life-history traits. Such competition may explain why autogeny is rare in field populations of L. cuprina even although underlying genetic variation for the trait seems to be present.

Efficacy of Monosodium Glutamate in the Australian Blowfly, Lucilia Cuprina Wiedmann (Diptera : Calliphoridae)

Abstract: Efficacy of monosodium glutamate (MSG) was studied in the Australian blowfly, Lucilia cuprina at six different doses, viz. 0.5, 1, 2, 3, 5 and 10 g, and the results were compared with the control. The effects of MSG were observed on the mortality, width and histology of Malpighian tubules (MTs) of the fly. The highest (100%) and lowest (16.67%) mortalities of the flies were recorded at 10g and 0.5g doses, respectively. Average widths of the MTs of flies in treatment (5g dose) and control were 48.62 μm and 58.85 μm, respectively. Histological observations through the cross section of the MTs showed the constriction at 0.5g and 5g doses. DOI: http://dx.doi.org/10.3329/bjz.v40i1.12896 Bangladesh J. Zool. 40 (1): 69-75, 2012