90 research outputs found

    Sexual size differences and colour polymorphism of Rhynchophorus phoenicis in the Southwest region of Cameroon

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    A total of 174 specimens of the African palm weevil Rhynchophorus phoenicis (F.) were sampled during 2010, in eight different localities of the Southwest region of Cameroon. Male and female weevils were measured (body length, abdomen length, abdomen width, pronotum length, pronotum width, head size, and length from tip of rostrum to antennal insertion), and the different pronotum patterns are described. Statistical analysis shows that all morphometric parameters correlate with body length in both males and females, and seven pronotum pattern types are identified, three of which are new. African palm weevil adults show sexual dimorphism: abdomen and head size are significantly greater in females, while pronotum length is significantly greater in males. No statistical differences in the frequencies of pronotum pattern types were seen between males and females, or among localities. A significant difference was seen for the abdomen width between two localities

    Exploitation of Tenebrio molitor larvae as biological factories for human probiotics, an exploratory study

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    The exploitation of yellow mealworm (Tenebrio molitor) larvae for the bioaugmentation of probiotic Bacillus clausii strains was evaluated during a 7-day rearing period. qPCR was applied to evaluate the persistence and growth of B. clausii in the rearing substrate and larvae (washed and non-washed). Moreover, the effect of freeze-drying of larvae on B. clausii viability was evaluated. The results demonstrated the suitability of yellow mealworm as biological factories for the multiplication of B. clausii through a simple and inexpensive procedure, in view of the further application of larvae as foods and food ingredients. In more detail, an increase in the load of B. clausii was observed during the 7-day rearing of larvae fed wheat middlings spiked with 1 Log cells g−1. Further research is needed to evaluate the most suitable technologies and processing parameters for obtaining yellow mealworm-based ingredients with a stable and active population of probiotic B. clausii

    Microbial dynamics in rearing trials of Hermetia illucens larvae fed coffee silverskin and microalgae

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    In the present study, Hermetia illucens larvae were reared on a main rearing substrate composed of a coffee roasting byproduct (coffee silverskin, Cs) enriched with microalgae (Schizochytrium limacinum or Isochrysis galbana) at various substitution levels. The microbial diversity of the rearing substrates, larvae, and frass (excrement from the larvae mixed with the substrate residue) were studied by the combination of microbial culturing on various growth media and metataxonomic analysis (Illumina sequencing). High counts of total mesophilic aerobes, bacterial spores, presumptive lactic acid bacteria, coagulase-positive cocci, and eumycetes were detected. Enterobacteriaceae counts were low in the rearing diets, whereas higher counts of this microbial family were observed in the larvae and frass. The microbiota of the rearing substrates was characterized by the presence of lactic acid bacteria, including the genera Lactobacillus, Leuconostoc and Weissella. The microbiota of the H. illucens larvae fed Cs was characterized by the dominance of Paenibacillus. H. illucens fed diets containing I. galbana were characterized by the presence of Enterococcus, Lysinibacillus, Morganella, and Paenibacillus, depending on the algae inclusion level, while H. illucens fed diets containing S. limacinum were characterized by high relative abundances of Brevundimonas, Enterococcus, Paracoccus, and Paenibacillus, depending on the algae inclusion level. Brevundimonas and Alcaligenes dominated in the frass from larvae fed I. galbana; the predominance of Brevundimonas was also observed in the frass from larvae fed Schyzochitrium-enriched diets. Based on the results of the present study, an effect of algae nutrient bioactive substances (e.g. polysaccharides, high-unsaturated fatty acids, taurine, carotenoids) on the relative abundance of some of the bacterial taxa detected in larvae may be hypothesized, thus opening new intriguing perspectives for the control of the entomopathogenic species and foodborne human pathogens potentially occurring in edible insects. Further studies are needed to support this hypothesis. Finally, new information on the microbial diversity occurring in insect frass was also obtained

    First report of Stephanostomum cesticillus (Molin, 1858) Looss, 1899 in Merluccius merluccius (Linnaeus, 1758) from the Tyrrhenian Sea (Southern Italy)

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    The genus Stephanostomum consists of digenean trematodes found in many marine teleosts. In this study, Stephanostomum cesticillus (Molin, 1858) Looss, 1899 metacercariae were identified in European hake (Merluccius merluccius, Linnaeus, 1758) caught in the Tyrrhenian Sea. The metacercariae were found encapsulated in the muscle, close to the spine and gills. Out of 131 specimens, 111 (P = 84.7%, mI = 25.1 mA = 21.3) were infected by digenean trematode metacercariae. Morphological and histological evaluations were carried out. The members of this genus are characterised by a double crown of spines close to the oral sucker. For identification of the parasite, molecular analysis was performed via 28S and 18S ribosomal DNA (rDNA) genes. Partial rDNA sequences of Stephanostomum highly matched to S. cesticillus for the percentage of similar identity from the nucleotide database of BLAST. The present survey reports the presence of S. cesticillus metacercariae in M. merluccius for the first time. Our results improve current knowledge on hake parasites to better understand the distribution of S. cesticillus in M. merluccius caught in the Mediterranean Sea and shed light on the life cycle of the parasite adding other possible hosts

    Distribution of Transferable Antibiotic Resistance Genes in Laboratory-Reared Edible Mealworms (Tenebrio molitor L.)

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    In the present study, the distribution of antibiotic resistance genes in laboratory-reared fresh mealworm larvae (Tenebrio molitor L.), their feeding substrates (carrots and wheatmeal), and frass was assessed. Microbial counts on selective media added with antibiotics highlighted the presence of lactic acid bacteria resistant to ampicillin and vancomycin and, more specifically, enterococci resistant to the latter antibiotic. Moreover, staphylococci resistant to gentamicin, erythromycin, tetracycline, and vancomycin were detected. Enterobacteriaceae resistant to ampicillin and gentamicin were also found, together with Pseudomonadaceae resistant to gentamicin. Some of the genes coding for resistance to macrolide-lincosamide-streptogramin B (MLSB) [erm(A), erm(C)], vancomycin [vanA, vanB], tetracycline [tet(O)], and β-lactams [mecA and blaZ] were absent in all of the samples. For the feeding substrates, organic wheatmeal was positive for tet(S) and tet(K), whereas no AR genes were detected in organic carrots. The genes tet(M), tet(K), and tet(S) were detected in both mealworms and frass, whereas gene aac-aph, coding for resistance to amynoglicosides was exclusively detected in frass. No residues for any of the 64 antibiotics belonging to 10 different drug classes were found in either the organic wheatmeal or carrots. Based on the overall results, the contribution of feed to the occurrence of antibiotic resistance (AR) genes and/or antibiotic-resistant microorganisms in mealworm larvae was hypothesized together with vertical transmission via insect egg smearing

    The HFE p.H63D (p.His63Asp) Polymorphism Is a Modifier of ALS Outcome in Italian and French Patients with SOD1 Mutations

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    Background: Data from published studies about the effect of HFE polymorphisms on ALS risk, phenotype, and survival are still inconclusive. We aimed at evaluating whether the p.H63D polymorphism is a modifier of phenotype and survival in SOD1-mutated patients. Methods: We included 183 SOD1-mutated ALS patients. Mutations were classified as severe or mild according to the median survival of the study population. Patients were screened for the HFE p.H63D polymorphism. Survival was calculated using the Kaplan-Meier modeling, and differences were measured by the log-rank test. Multivariable analysis was performed with the Cox proportional hazards model (stepwise backward). Results: SOD1 severe mutation carriers show more frequent familial history for ALS and shorter survival compared to mild mutation carriers. Carriers and non-carriers of the p.H63D polymorphism did not differ in terms of sex ratio, frequency of positive familial history, age at onset, and bulbar/spinal ratio. In univariate and in Cox multivariable analysis using sex, age at onset, site of onset, family history, country of origin, and mutation severity as covariates, p.H63D carriers had a longer survival (p = 0.034 and p = 0.004). Conclusions: We found that SOD1-mutated ALS patients carrying the p.H63D HFE polymorphism have a longer survival compared to non-carriers, independently of sex, age and site of onset, family history, nation of origin, and severity of mutations, suggesting a possible role as disease progression modifier for the p.H63D HFE polymorphism in SOD1-ALS

    Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis

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    Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.Objective: To identify the genetic variants associated with juvenile ALS.Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism.Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members.Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway.Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.</p

    Paysandisia archon (Burmeister): il Lepidottero minatore delle palme

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    L’Italia è un importante crocevia commerciale ed offre un’ampia gamma di parametri climatici. Queste caratteristiche hanno costituito un fattore determinante per l’introduzione e l’acclimatamento di molte delle 552 specie di insetti alloctone dannose negli ecosistemi italiani. La rapida crescita di questa “immigrazione”, negli ultimi decenni, è favorita dall’aumento degli scambi commerciali, del turismo e del trasporto di merci tra paesi diversi. Ed è grazie agli scambi commerciali fra Argentina, Spagna e Italia che è arrivato nel nostro Paese Paysandisia archon (Burmeister, 1880) (Lepidoptera: Castniidae), un insetto dannoso alle palme sia in ambiente produttivo sia in ambiente urbano. In questo lavoro vengono illustrate le piante ospiti, la descrizione dell'insetto, il ciclo biologico ed i mezzi di controllo da utilizzare nei confronti di questo lepidottero minatore delle palme

    Indagini biologiche su un lepidottero minatore delle palme di recente introduzione in Italia

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    Vengono riportate informazioni sul ciclo biologico e sulle piante ospiti di Paysandisia archon nella regione Marche
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