Determination of antibiotic resistance pattern and virulence genes in Escherichia coli isolated from bovine with subclinical mastitis in southwest of Iran

The aims of the present study were to investigate the prevalence of some virulence genes and also determine the antimicrobial resistance pattern of E. coli isolated from bovine with subclinical mastitis. The milk of 502 cows was collected from 8 dairy herds in the southwest of Iran. Conventional biochemical tests were used for identification of E. coli at the species level. Antimicrobial susceptibility patterns of E. coli isolates were determined by disc agar diffusion method and polymerase chain reaction (PCR) was used for detection of seven virulence genes including f17A, afaE-8, afaD-8, eaeA, cnf1, cnf2, and iucD. Seventy (13.94%) isolates of E. coli were identified in 502 milk samples. The highest rate of resistance was observed against tetracycline (18.6%), while none of the isolates were resistant to streptomycin. Eight (11.5%) out of 70 E. coli isolates carried at least one of the virulence genes. The afaD-8 was the most prevalent gene detected in 5 (7.1%) isolates. The afaE-8, iucD, and eaeA were detected in 3, 3, and 2 isolates respectively. Low prevalence of virulence factors may be indicating that most of the E. coli isolates originated from the commensal flora of cows and enter to the udders via environment contamination with feces.

     

Effects of medium-chain fatty acids on performance,carcass characteristics,blood biochemical parameters and immune response in Japanese quail

1. This study had the aim of evaluating the effects of medium-chain fatty acids (MCFA) on performance, carcass characteristics, some blood parameters and antibody titre against sheep red blood cells (SRBC) in quail.

2. A total of 240 quail chicks were allotted to 4 treatments consisting of respectively 0, 1, 2 and 4 g/kg dietary MCFA.

3. There were no significant differences in body weight, feed intake and feed conversion ratio among treatments at different stages of the experiment.

4. MCFAs had no significant effect on breast, thigh, liver, spleen and bursa of Fabricius weight ratios. However, the relative weight of abdominal fat significantly decreased in quail receiving 0.2 and 0.4 MCFA as compared to other treatments.

5. Concentrations of low-density lipoprotein-cholesterol (LDL), triglycerides and total cholesterol were decreased and high-density lipoprotein (HDL)-cholesterol was increased in quail chicks receiving MCFA compared with control quail chicks. The concentrations of SRBC antibody were not statistically different among treatments.

6. It is concluded that MCFA significantly decreased LDL, triglycerides, cholesterol and abdominal fat and increased HDL in quail chicks.

     

Rapid screening of toxigenic vibrio cholerae O1 strains from south Iran by PCR-ELISA

BACKGROUND: The ability to sensitively detect Vibrio cholera with PCR-ELISA method represents a considerable advancement over alternative more time-consuming methods for detection of this pathogen. The aim of this research is to evaluate the suitability of a PCR-enzyme-linked immunosorbent assay for sensitive and rapid detection of V. cholera O1. METHODS: The 398-bp sequence of a gene that codes for the cholera toxin B subunit was amplified by PCR. The digoxigenin-labeled amplified products were coated on microplates and detected by ELISA. The PCR product was also hybridized with biotin labelled probe and detected by ELISA using streptavidin. RESULTS AND CONCLUSION: The specificity of the PCR was determined using 10 bacterial strains and 50 samples from south Iran. The detection limit was 0.5 pg of the genomic DNA and five bacterial cells. Adaptation of PCR into PCR-ELISA assay format facilitates specific and sensitive detection and diagnosis of human cholera disease. We conclude that this PCR-ELISA is a diagnostic method that specifically detects toxin genes in V. cholera O1 strains. It is more rapid and less cumbersome than other diagnostic methods for detection of toxicity in these strains.     

Investigation and modeling of air permeability of Cotton/Polyester blended double layer interlock knitted fabrics

The aim of this study was to analyze and model the effect of knitting parameters on the air permeability of Cotton/Polyester double layer interlock knitted fabrics. Fabric samples of areal densities ranging from 315–488 g/m² were knitted using yarns of three different cotton/polyester blends, each of two different linear densities by systematically varying knitting loop lengths for achieving different cover factors. It was found that by changing the polyester content in the inner and outer fabric layer from 52 to 65 % in the double layer knitted fabric did not have statistically significant effect on the fabric air permeability. Air permeability sharply increased with increase in knitting loop length owing to decrease in fabric areal density. Decrease in yarn linear density (tex) resulted in increase in air permeability due to decrease in areal density as well as the fabric thickness. It was concluded that response surface regression modeling could adequately model the effect of knitting parameters on the double layer knitted fabric air permeability. The model was validated by unseen data set and it was found that the actual and predicted values were in good agreement with each other with less than 10 % absolute error. Sensitivity analysis was also performed to find out the relative contribution of each input parameter on the air permeability of the double layer interlock knitted fabrics.     

Spatio-temporal variability of drought characteristics across Pakistan

Climate change in Pakistan has a great impact on the spatial and temporal variation of precipitation and ultimately alters the frequency and duration of droughts. In this study, spatial and temporal trend analyses of precipitation and droughts were observed at 58 meteorological stations across Pakistan from 1981 to 2018. The existing trend analysis methods were evaluated to address the issue of serial correlation in the climatic data. Results of precipitation analysis showed significant decreasing trends in winter (November, December) and significant increasing trends were observed in summer (June and September) at a confidence level of 95 percent. The magnitude of the precipitation trends showed the highest variation during summer season and the least variation in winter season. Rotated Principal Component (RPC) analysis showed the severe droughts (high positive loading) in southeastern side (Sindh province) of Pakistan due to lack of summer rains. Furthermore, variance correction approaches are identified as the most suitable in coping with the effect of serial correlation. The highest drought frequencies were observed in the southern areas of Pakistan and the drought events are expected to occur more frequently in the late winter, early spring, and early autumn, while droughts were expected to occur least frequently in summer.

     

Interaction of Rhizobium and Pseudomonas with Wheat (Triticum Aestivum L.) in Potted Soil with or Without P2O5

The effect of inoculation of Rhizobium or Pseudomonas, or both, in the presence and absence of phosphorus pentoxide (P₂O₅) fertilizer on wheat yield was tested. The experiment was conducted outdoors in potted soil during two consecutive years under natural conditions. Rhizobial strain (Thal 8-chickpea nodulating bacteria) and Pseudomonas strain (54RB), both indigenous P solubilizers were applied in broth culture at seedling stage. Fertilizer in the form of P₂O₅ was an additional treatment applied at sowing time. Results revealed that inoculation of Pseudomonas strain in presence of phosphorus (P) fertilizer increased yield up to 41.8% when it was compared with only P fertilizer applied. Co-inoculation of Rhizobium and Pseudomonas strains with the P₂O₅ treatment however resulted in increased grains yield by 10% over the P₂O₅ treatment alone. It is inferred that inoculation with Rhizobium and Pseudomonas combined with P₂O₅ is not only environmentally beneficial but also economically sound and productive, with wheat yield increases of 10% to 42%.     

Effects of short-term cooling on pregnancy rate of dairy heifers under summer heat stress

Thermal stress in cattle results in major decreases in dairy production and reproduction. A study was designed to evaluate the influence of temporary cooling on pregnancy rate in Holstein heifers during summer heat stress. Estrus was synchronized with two injections of prostaglandin (PG), administrated 11 d apart, and all heifers were housed in a shaded enclosed structure at the time of the second PG injection. After estrus detection, heifers were randomly divided into three groups: Control (C; n = 30), Sprinkler (S; n = 30) or Sprinkler and Fan (SF; n = 30). Rectal temperatures were measured 2.5 hours before AI, at the time of AI, and 1.5 and 3.5 hours after AI. Group C heifers receive no further treatment, but heifers in S and SF groups were exposed to short-term cooling from 2 hours before until 2 hours after AI with a sprinkler (S) or sprinkler and a fan (SF), respectively. Estrus detection and AI were performed by a single skilled technician; semen was from a bull of known fertility. Rectal temperature did not differ among groups 2.5 hours before AI, but at the time of AI was lower (P < 0.05) in SF group (39.3 ± 0.0°C) than in S (39.5 ± 0.0°C) and C (39.9 ± 0.1°C) groups which also differed (P < 0.05). At 1.5 and 3.5 hours after AI, rectal temperature remained lower in SF group (38.9 ± 0.0 and 38.7 ± 0.0°C, respectively) than in the S (39.4 ± 0.0 and 39.2 ± 0.0°C, respectively) and C (39.3 ± 0.0 and 39.3 ± 0.0°C, respectively) groups, which no longer differed. Pregnancy rate following AI was higher (P < 0.05) in SF group (56.7%) than in the C group (23.3%) with the S group (40%) intermediate and not different from either. The present study results indicate that cooling of dairy heifers for a short time before and after AI, especially with sprinkler and fan, can increase pregnancy rate during heat stress.     

Yellow mealworm,Tenebrio molitor (Col: Tenebrionidae), larvae powder as dietary protein sources for broiler chickens: Effects on growth performance,carcass traits,selected intestinal microbiota and blood parameters

This study was conducted to evaluate the effects of dietary Tenebrio molitor larvae meal (TM meal) inclusion on the performance, carcass traits, caecum microbiota and blood parameters of broiler chickens. A total of 180-day-old chickens were allocated to three dietary groups with five replicate pens (12 birds/pen). Experimental diets were included a corn-soybean basal diet, and two diets with 2.5% and 5% TM. TM-included diets have been administered for periods of starter (1–10 days) and grower (11–25 days). A regular finisher diet was given to all groups during the 26–42 days of age. Diets containing TM meal did not influence feed intake and mortality percentage. Feed conversion ratio was lower with the 2.5% TM meal diet compared with the control group at starter period (p < .05). Besides, broiler chickens fed TM meal included diet had a higher body weight gain than the control group during 1–10 days of age (p < .05). The carcass characteristics and length and weight of different parts of small and large intestines were not influenced by diets. TM meal inclusion decreased the albumin-to-globulin ratio compared with the control group (p < .05). Additionally, lower total count of aerobic and Escherichia coli bacteria was observed in response to diet inclusion of 5% TM meal. Overall, the inclusion of TM meal in broilers' diet improved body weight gain and feed conversion ratio in the starting period, decreased albumin-to-globulin ratio and E. coli bacteria content.     

Effects of supplementation with digestible undegradable protein in late pregnancy on ewe colostrums production and lamb output to weaning

The aim of this study was to investigate the effects of supplementation with digestible undegradable protein (DUP) in diet during late pregnancy on colostrum production, lamb survival and growth. For 3 weeks prior to lambing, 41 Afshari ewes were assigned at random to three dietary treatments, namely a control (CDUP), moderate (MDUP) and high (HDUP) DUP group. The ewes (n = 14) in CDUP group were fed a protein maintenance level for pregnant ewes [83 g metabolizable protein (MP)/kg dry matter (DM)], while ewes in the MDUP (n = 13) and HDUP (n = 14) groups were fed diets provided 14% (94.7 g MP/kg DM) and 24% (104.3 g MP/kg DM) MP in excess of these requirements respectively, which this increment was coming from DUP (DUP/MP ratio 43.8; 51.0% and 57.6% respectively). All diets were isoenergetic (12 MJ ME/kg DM). All ewes received the same lactation diet after lambing. Ewes in HDUP tend to produce more colostrums (p < 0.1) and had higher protein, fat, and solids non-fat content (p < 0.05) in colostrums during the first 24 h after lambing. MDUP group had higher colostrum yield compared to CDUP (p < 0.1). The changes in body weight and body condition score of ewes were similar for all diets but placenta weight was higher in MDUP group (p < 0.05) than for HDUP and CDUP ewes. Lamb body weight at weaning was higher for males compared to females (p < 0.05), but was not different between treatments. HDUP ewes had higher blood glucose concentration in the pre-lambing period than other treatments (p < 0.05). In this period, increasing the level of DUP in diet increased the content of blood urea nitrogen (p < 0.05). It was concluded that increasing the DUP content of diet for 3 weeks prior to lambing above the standard requirements resulted in an increase in colostrums production but had no effect on lamb outcome to weaning.     

FOLIAR APPLICATION OF BORON INFLUENCES THE LEAF MINERAL STATUS,VEGETATIVE AND REPRODUCTIVE GROWTH,YIELD AND FRUIT QUALITY OF ‘KINNOW’ MANDARIN (CITRUS RETICULATA BLANCO.)

The effects of foliar application of boron (B) in the form of boric acid on vegetative and reproductive growth, yield and fruit quality of ‘Kinnow’ mandarin (Citrus reticulate Blanco.) were investigated. Kinnow mandarin was sprayed with different concentrations of boric acid viz. (0.1%, 0.2%, 0.3% and 0.4%) at fruit set stage. Leaf nitrogen (N), phosphorus (P), potassium (K), B, and zinc (Zn) along with flush length, tree height, tree spread and tree trunk diameter increased, while leaf length and leaf age showed non-significant results after foliar B application. Yield of the ‘Kinnow’ mandarin was significantly affected by foliar application of B and a significant increase in fruit weight at harvest was also observed. Soluble solid concentration (SSC): titratable acidity (TA) ratio, ascorbic acid, total sugars, total phenolic content (TPC) and total antioxidants significantly affected, while pH of juice, SSC, TA, reducing sugars and non-reducing sugars showed non- significant results.