Diagnosis of Campylobacter spp. Isolates and Their Antimicrobial Susceptibility Patterns.

This study aimed to reveal antibiotic resistance patterns and molecular characterization of quinolone resistance Campylobacter isolates in patients with diarrhea. Campylobacter spp. isolated from 35.33% of the total samples, most of which were from male patients aged 3 months to 10 years. Identifying isolates at the species level made in MALDI-TOF MS, 82.4% were C. jejuni, and 17.6% were C. coli. Respectively 94% (47/50), 58% (29/50), and 2% (1/50) resistance rates were determined for ciprofloxacin, tetracycline, and erythromycin. While C. jejuni isolates were more resistant to ciprofloxacin and tetracycline than C. coli, they showed no resistance to erythromycin. Quinolone resistance determining region (QRDR) were evaluated by mismatch amplification mutation test and all quinolone resistant strains gave positive results. One of the seven silent mutations identified was specific to this study, and two other novel mutations were also identified. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01199-5.

Genome mining of Bacillus thuringiensis strain SY49.1 reveals novel candidate pesticidal and bioactive compounds.

BACKGROUND: Bacillus thuringiensis SY49.1 (Bt SY49.1) strain has promising insecticidal and fungicidal activity against phytopathogens and pests. Therefore, we selected this strain for whole-genome sequencing (WGS), annotation and analysis, with the aim of identifying genes responsible for producing putative pesticidal toxins, antimicrobial metabolites and plant growth-promoting features. RESULTS: Our results showed that the SY49.1 genome is 6. 32 Mbp long with a GC content of 34.68%. Genome mining revealed the presence of multiple gene inventories for the biosynthesis of bioactive compounds such as insecticidal delta endotoxins, secondary metabolites, and several plant growth-promoting proteins. Multiple sequence alignment revealed residue variations in the toxic core of Cry1Ab when compared with known Cry1Ab sequences from Bt nomenclature databases. This suggests that the cry1Ab of SY49.1 is a new kind of its group. Among the predicted secondary metabolites, we found a kurstakin with a predicted peptide that differs from the known kurstakin peptide available in the NORINE database. In addition, lipopeptides extracted from SY49.1 suppressed the growth of Verticillium dahliae and Fusarium oxysporum. CONCLUSION: We anticipate that the complete genome of Bt SY49.1 may provide a model for properly understanding and studying antimicrobial compound mining, genetic diversity among the B. cereus group, and pathogenicity against insects. This is the first report on the WGS and mining of the Bt strain isolated from Turkey. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Cellular and Transcriptional Adaptation of Bovine Granulosa Cells Under Ethanol-Induced Stress In Vitro.

AIMS: Granulosa cells (GCs) are the major cellular component in a follicular microenvironment and play an indispensable role in ovarian function. This study was conducted to investigate the effects of ethanol exposure on the cellular and transcriptional changes of ovarian GCs. METHODS: For this purpose, bovine GCs were exposed to different concentrations of ethanol (0, 50, 100, 200, 500 and 1000) to mimic the effects of alcohol in in vitro. Subsequently, 100 and 1000 mM concentrations were discarded from further experiments, as 100 mM was not different from 50 mM, and 1000 mM was supertoxic to the cells. RESULTS: The results showed that there was a gradual loss of cell viability with the increase of the ethanol concentration, i.e. lowest viability was observed at the highest concentration (1000 mM), which is further supported by cell proliferation assay. Mitochondrial activity decreased significantly at higher concentrations. The expression of NRF2 decreased significantly (P < 0.05) in ethanol-exposed cells compared with the cells in the control group at the 6-h time point, whereas the expression was increased in 500 mM concentration at the 24-h time point. The expression of antioxidant genes, downstream to Nrf2-pathway activation, showed that overall expression pattern similar to NRF2. CONCLUSION: The result of this study prompted us to postulate that ethanol exposure decreases the ability of GCs to handle stress by downregulating the expression of genes involved in Nrf2-pathway.

Cloning and expression of cry2Aa from native Bacillus thuringiensis strain SY49-1 and its insecticidal activity against Culex pipiens (Diptera: Culicidae).

Bacillus thuringiensis (Berliner) (Bt) is well known for having toxicity against pest insects because of their ability to form endospores and broad-range activity of their parasporal inclusions. In this study, a new member of cry2A gene from previously characterized native B. thuringiensis SY49-1 strain was cloned, expressed and used for its activity against Culex pipiens (Diptera: Culicidae) larvae. The sequence analysis of the cloned cry2A gene revealed that it encodes a polypeptide of 633 aa residues with 99% identity to Cry2Aa protein with expected molecular weight of 70.7 kDa. Bacillus thuringiensis delta-endotoxin nomenclature committee designed our sequence as Cry2Aa18 being a new member of Bt toxins. Bioassays against last instar larvae of C. pipiens indicated that Cry2Aa18 has considerable toxicity with LC50 of 630 µg ml-1. In order to prevent the spread of infectious diseases mediated by C. pipiens, this newly characterized cry2Aa18 gene could constitute as an important biological control tool for controlling mosquito larvae living in freshwater systems and can be used as a good alternative for minimizing the use of chemicals.

Expression of cry1Ab gene from a novel Bacillus thuringiensis strain SY49-1 active on pest insects

ABSTRACT In this study, the cry1Ab gene of previously characterized and Lepidoptera-, Diptera-, and Coleoptera-active Bacillus thuringiensis SY49-1 strain was cloned, expressed and individually tested on Ephestia kuehniella (Lepidoptera: Pyralidae) and Plodia interpunctella (Lepidoptera: Pyralidae) larvae. pET-cry1Ab plasmids were constructed by ligating the cry1Ab into pET28a (+) expression vector. Constructed plasmids were transferred to an Escherichia coli BL21 (DE3) strain rendered competent with CaCl2. Isopropyl β-D-1-thiogalactopyranoside was used to induce the expression of cry1Ab in E. coli BL21(DE3), and consequently, ∼130 kDa of Cry1Ab was obtained. Bioassay results indicated that recombinant Cry1Ab at a dose of 1000 µg g-1 caused 40% and 64% mortality on P. interpunctella and E. kuehniella larvae, respectively. However, the mortality rates of Bt SY49-1 strains' spore-crystal mixture at the same dose were observed to be 70% on P. interpunctella and 90% on E. kuehniella larvae. The results indicated that cry1Ab may be considered as a good candidate in transgenic crop production and as an alternative biocontrol agent in controlling stored product moths.

Expression of cry1Ab gene from a novel Bacillus thuringiensis strain SY49-1 active on pest insects.

In this study, the cry1Ab gene of previously characterized and Lepidoptera-, Diptera-, and Coleoptera-active Bacillus thuringiensis SY49-1 strain was cloned, expressed and individually tested on Ephestia kuehniella (Lepidoptera: Pyralidae) and Plodia interpunctella (Lepidoptera: Pyralidae) larvae. pET-cry1Ab plasmids were constructed by ligating the cry1Ab into pET28a (+) expression vector. Constructed plasmids were transferred to an Escherichia coli BL21 (DE3) strain rendered competent with CaCl2. Isopropyl ß-d-1-thiogalactopyranoside was used to induce the expression of cry1Ab in E. coli BL21(DE3), and consequently, ∼130kDa of Cry1Ab was obtained. Bioassay results indicated that recombinant Cry1Ab at a dose of 1000µgg(-1) caused 40% and 64% mortality on P. interpunctella and E. kuehniella larvae, respectively. However, the mortality rates of Bt SY49-1 strains' spore-crystal mixture at the same dose were observed to be 70% on P. interpunctella and 90% on E. kuehniella larvae. The results indicated that cry1Ab may be considered as a good candidate in transgenic crop production and as an alternative biocontrol agent in controlling stored product moths.

Chemical composition and fumigant toxicity of some essential oils against Ephestia kuehniella.

The chemical constituents of some essential oils extracted from aromatic plants (savory, Satureja thymbra L.; Turkish oregano, Origanum onites L.; myrtle, Myrtus communis L.; marjoram, Origanum majorana L.; laurel, Laurus nobilis L.; lemon, Citrus limon L.; sticky goosefoot, Chenopodium botrys L.; and tansy, Tanecetum armenum [DC.] Suchultz Bip.) were analyzed by gas chromatography-mass spectrometry. Fumigant toxicity of volatile compounds was tested against Mediterranean flour moth, Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), eggs and adults. Percentage of mortality and longevity of E. kuehniella adults were estimated after essential oil treatments. LC50 and LC99 values were determined for each exposure time for each essential oil. Marjoram and lemon oils were the most effective of all the essential oils tested. The major components were linalool, 1.8-cineole, citral, 2-(4a.8-dimethyl-1.2.3.4.4a.5.6.7-octahydro-naphthalen-2-yl)-prop-2-en-l-ol, and p-cymene for marjoram, laurel, lemon, goosefoot, and tansy, respectively. The LC50 and LC99 values were estimated as 3.27 and 5.13 microl liter(-1) air for marjoram and 4.05 and 5.57 microl liter(-1) air for lemon essential oils at the longest exposure time. Decreasing longevity effect of marjoram and lemon was more prominent compared with other essential oils. We suggest that essential oils obtained from certain aromatic plants have potential as fumigants for stored product pests.

Insecticidal activity of the essential oils from different plants against three stored-product insects.

This study was conducted to determine the insecticidal activity of essential oils from oregano, Origanum onites L. (Lamiales: Lamiaceae), savory, Satureja thymbra L. (Lamiales: Lamiaceae), and myrtle, Myrtus communis L. (Rosales: Myrtaceae) against three stored-product insects. Essential oils from three species of plants were obtained by Clevenger-type water distillation. The major compounds in these essential oils were identified using gas chromatography-mass spectrometry and their insecticidal activity was tested against adults of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), the Indian meal moth Plodia interpunctella Hübner (Lepidoptera: Pyralidae) and the bean weevil Acanthoscelides obtectus Say (Coleoptera: Bruchidae). While the major compound found in oregano and savory was carvacrol, the main constituent of the myrtle was linalool. Among the tested insects, A. obtectus was the most tolerant species against the essential oils. However, the insecticidal activity of the myrtle oil was more pronounced than other oils tested against A. obtectus adults. The essential oils of oregano and savory were highly effective against P. interpunctella and E. kuehniella, with 100% mortality obtained after 24 h at 9 and 25 microl/l air for P. interpunctella and E. kuehniella, respectively. LC(50) and LC(99) values of each essential oil were estimated for each insect species.

Gamma radiation sensitivity of the eggs, larvae and pupae of Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae).

BACKGROUND: This study focused on determining the minimal effective gamma radiation dose that prevents commodity damage caused by the Indian meal moth Plodia interpunctella (Hübner). The study was also designed to assess the effect of releasing either partially sterilized males alone or both partially sterilized males and females on the reproductive potential of P. interpunctella populations. RESULTS: The dose of radiation required to prevent larval emergence from irradiated eggs was 350 Gy, and the same dose was also required to prevent adult emergence from mature larvae. A dose of 300 Gy was not able to prevent adult emergence from irradiated pupae. The dose at which 100% sterility was achieved in treated females mated to treated males was 300 Gy for the parental generation of irradiated pupae. Fertility of the parental males from irradiated pupae was 48.17% at 300 Gy in treated males crossed with untreated females, but male progeny of irradiated male parents had a residual fertility of 11.06% at the same dose. CONCLUSION: F(1) males from irradiated pupae were more sterile than parental males. To prevent larval emergence from irradiated eggs, a dose of 350 Gy is required. The same dose is required to prevent the larvae from reaching the adult stage.