Effects of probiotics: alone and in a mixture of Biosacc plus Zinc Bacitracin on the caecal microflora of Japanese quail

The aim of this study was to investigate the effects of two commercially available probiotics, alone and in combination with an antibiotic, on the caecal flora of Japanese quail (Coturnix coturnix japonica) reared under unstressed conditions. Thirty-four 90-day-old Japanese quail were selected for this study. The birds were divided into four groups, two groups of nine birds and two groups of eight birds. The animals in these groups were given feed containing 0.5 kg per tonne of probiotics alone (Protexin or Biosacc), a mixture of probiotic plus antibiotic (Biosacc plus Zinc Bacitracin at 0.5 and 0.0525 ppm, respectively), and a group where no supplement was added to be used as controls. The total count of aerobic bacteria, lactobacilli, enterobacteriaceae, coliforms, enteroccoci, salmonellae, sulphite-reducing anaerobic bacteria (clostridia), and pH values in the caecal content of the birds were examined. No significant differences were detected among the four groups for pH values and bacterial number (p>0.05), except for sulphite-reducing anaerobic bacteria (p<0.001). These results suggest that the use of probiotics alone and/or a mixture of a probiotic plus antibiotic as a feed supplement does not have a major suppressing effect on the majority of bacterial groups in the caecal flora of mature, healthy Japanese quail reared in unstressed conditions.     

Note: Pyrethroid resistance and possible involvement of glutathione<Emphasis Type="Italic">S</Emphasis>-transferases in<Emphasis Type="Italic">Helicoverpa armigera</Emphasis> from Turkey

An introductory study was conducted to investigate the pyrethroid resistance ofHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) strains in Turkey, collected from cotton fields in the Adana and Antalya provinces, through two different synthetic pyrethroid insecticides: lambda-cyhalothrin and esfenvalerate. In addition, the roles of glutathioneS-transferases (GSTs) in this resistance mechanism were analyzed. It was found that whereas resistance ratios for lambda-cyhalothrin (LD₅₀ levels) were 3- and 98-fold increased in the Adana and Antalya strains, respectively, esfenvalerate ratios were 3.3- and 92.3-fold increased in the Adana and Antalya strains, respectively, with respect to the susceptible strain. Furthermore, Adana and Antalya strains showed 2.4- and 2.9-fold higher GST activities than the susceptible strain, respectively. In the Antalya field strain, the minor increase in GST activity compared with the resistance levels implies that GSTs may be not greatly involved in this resistance. It also provides evidence that they could not be the only metabolic mechanism responsible for resistance to lambda-cyhalothrin and esfenvalerate inH. armigera from Turkey. http://www.phytoparasitica.org posting Nov. 16, 2006.     

Combined Removal of Zinc (II) and Cadmium (II) from Aqueous Solutions by Adsorption onto High-Calcium Turkish Fly Ash

The aim of this work is the investigation of possible use of flyash in the removal of zinc (Zn²⁺) and cadmium (Cd²⁺) contained in aqueous solutions. Batch adsorption experiments wereperformed in order to evaluate the removal efficiency oflignite-based fly ash. The parameters studied include contact time, pH,temperature, initial concentration of the adsorbate and fly ashdosage. The contact time necessary to attain equilibrium was found to be two hours. Maximum adsorption occurred in the pH range of 7.0 to 7.5. The percent adsorption of Zn²⁺ and Cd²⁺ increased with an increase in concentration of Zn²⁺ and Cd²⁺, dosage of fly ash and temperature. Theapplicability of Langmuir isotherm suggests the formation ofmonolayer coverage Zn²⁺ and Cd²⁺ ions at the outer surface of the adsorbent. Thermodynamic parameters suggested the endothermic nature of the adsorption process. The fly ashwas found to be an metal adsorbent as effective as activated carbon.     

Preliminary Assessment of Dietary Mannanoligosaccharides on Growth Performance and Health Status of Gilthead Seabream Sparus auratus

Abstract

A feeding trial was performed to assess the potential beneficial effect of two levels of mannanoligosaccarides (MOS) on the growth performance, feed utilization, hematological parameters, and liver histopathology of gilthead seabream Sparus auratus (also known as gilthead bream). Mannanoligosaccarides were added at the rates of 2 and 4 g/kg to a fish-meal-based control diet, and each diet was given (twice daily [midmorning and midafternoon] to apparent satiation) to triplicate groups of gilthead seabream growers (mean weight = approximately 170 g) in sea cages. The trial lasted 12 weeks, and the average ambient water temperature ranged from 19.6°C to 24.7°C during the experimental period. At the end of the experiment, fish attained market size (350–450 g) and their health status was evaluated by blood analysis and liver histology. There were no differences in survival rates among fish fed experimental diets. However, there were significant improvements in both growth and feed utilization among fish fed diets supplemented with MOS. Hemoglobin (Hb) and hematocrit (Ht) levels and erythrocyte, leukocyte, and thrombocyte (Thr) counts were unaffected by any dietary MOS. The levels of Hb (g/dL; mean ± SD) and Ht (%; mean ± SD) were 11.0 ± 2.5 and 45.6 ± 6.7 for the control group, 11.1 ± 1.7 and 39.3 ± 8.0 for the 2-g/kg group, and 11.2 ± 1.9 and 40.2 ± 8.4 for the 4-g/kg group. The mean Thr count ranged from 47.6 to 53.8 × 10³/mm³. Despite the apparently higher Thr counts for fish fed diets supplemented with MOS, these differences were not significant. Moreover, no histopathological differences were observed in liver tissue cross sections between control and treatment groups. These results suggest that supplementation of diets with MOS had no significant effects on general fish health.

Received February 20, 2011; accepted September 12, 2011     

Prevalence and Characterization of Coagulase Positive Staphylococci Isolated from Salted Anchovy

A total of 100 salted anchovy samples were used to investigate the prevalence of S. aureus and other coagulase positive Staphylococci (CPS) as well as to determine the methicillin (MR) and antibiotic resistance (AR) profile, the presence of Panton-Valentine leukocidine (PVL) toxin gene (lukS/F-PV), slime factor properties (SFP), and the genotypic relatedness of the isolates. Agar disc diffusion assay (ADDA) and microdilution broth susceptibility test (MDBST) were applied to compare the specificity and sensitivity of the MR detection methods. A total of 41 CPS isolates were detected at the 10² and 10³ CFU/g levels in contrast to S. aureus. The 16S rRNA (genus specific) was detected in all the isolates in contrast to nuc (species-specific) and lukS/F-PV genes. A total of 16/41 isolates were found to be MR by using the three methods. Polymerase chain reaction (PCR) assay was a more sensitive and reliable method for the detection of MR isolates. The antibiotic resistance rates were 75.60, 73.17, 51.21, 31.70, 12.19, and 4.87% to penicillin, ampicillin, tetracycline, erythromycin, ciprofloxacin, and clindamycin, respectively. All the isolates were sensitive to gentamicin and vancomycin. The SFP were determined in all the isolates by using Congo Red agar, and 20 different genotypes were determined by using randomly amplified polymorphic DNA (RAPD)-PCR assay.     

Prevalence and Serotype Distribution of Listeria monocytogenes in Salted Anchovy,Raw Anchovy,and Raw Mussel Using IMS-Based Cultivation Technique and PCR

In the present study, a total of 150 samples including 50 salted anchovy, 50 raw anchovy, and 50 raw mussel samples collected from the retailers and small-scale producers in Samsun province from the Black Sea region of Turkey were analyzed; and 12% (6/50), 2% (1/50), and 2% (1/50) of the samples, respectively, were found to be contaminated with L. monocytogenes. According to the serotype distribution, six salted anchovy and one of the raw fish samples were contaminated with L. monocytogenes 1/2b (or 3b). In one raw mussel, both L. monocytogenes 1/2b (or 3b) and 4b (or 4d or 4e) serotypes were detected.     

Modelling the dynamics of intramammary E. coli infections in dairy cows: understanding mechanisms that distinguish transient from persistent infections

The majority of intramammary infections with Escherichia coli in dairy cows result in transient infections with duration of about 10 days or less, although more persistent infections (2 months or longer) have been identified. We apply a mathematical model to explore the role of an intracellular mammary epithelial cell reservoir in the dynamics of infection. We included biological knowledge of the bovine immune response and known characteristics of the bacterial population in both transient and persistent infections. The results indicate that varying the survival duration of the intracellular reservoir reproduces the data for both transient and persistent infections. Survival in an intracellular reservoir is the most likely mechanism that ensures persistence of E. coli infections in mammary glands. Knowledge of the pathogenesis of persistent infections is essential to develop preventive and treatment programmes for these important infections in dairy cows.     

Detection of Escherichia coli O157 and Escherichia coli O157:H7 by the immunomagnetic separation technique and stx1 and stx2 genes by multiplex PCR in slaughtered cattle in Samsun Province, Turkey

This study was conducted to investigate the presence of Escherichia (E.) coli O157 and E. coli O157:H7 and stx1 and stx2 genes on cattle carcasses and in rectal samples collected from Samsun Province of Turkey. A total of 200 samples collected from cattle carcasses and the rectal contents of 100 slaughtered cattle from two commercial abattoirs were tested using the immunomagnetic separation technique and multiplex PCR methods. E. coli O157 and E. coli O157:H7 were detected in 52 of the 200 samples (26%) tested. Of the positive samples, 49 were E. coli O157 and three were E. coli O157:H7. The E. coli O157 strain was isolated from 24 carcasses and 25 rectal samples, while E. coli O157:H7 was isolated from two carcasses and one rectal sample. Of the 49 samples positive for E. coli O157, 32 were from the rectal and carcass samples of the same animal, while two E. coli O157:H7 isolates were obtained from rectal swabs and carcasses of the same animal. The stx1 and stx2 genes were both detected in 35 E. coli O157 isolates and one E. coli O157:H7 isolate, but the stx2 gene was only detected alone in two E. coli O157 isolates. Overall, 16 carcasses tested positive for E. coli O157 and one carcass tested positive for E. coli O157:H7 based on both carcass and rectal samples. Overall, the results of this study indicate that cattle carcasses pose a potential risk to human health due to contamination by E. coli O157 and E. coli O157:H7 in the feces.     

Adherent and invasive Escherichia coli are associated with persistent bovine mastitis

Bovine mastitis caused by Escherichia coli has traditionally been viewed as a transient infection. However, E. coli can also cause clonal persistent intramammary infection (IMI) in dairy cows. In this study, we explored the possibility that E. coli strains associated with persistent IMI are better able to adhere to, invade, survive and replicate in cultured mammary epithelial cells (MAC-T) than transient strains, and examined their serotype, overall genotype, phylogenetic group, and the presence of known virulence genes. Both transient and persistent E. coli strains adhered to MAC-T cells, but persistent strains invaded MAC-T cells 2.6-63.5 times more than transient strains. Blocking the adhesin/invasin FimH with mannose diminished but did not eliminate adhesion and invasion of any strain. Cytoskeletal and protein kinase inhibitors cytochalasin D, colchicine, genistein and wortmannin dramatically reduced invasion of MAC-T cells by both strains. All of the persistent strains, but only one transient strain, were able to survive and replicate intracellularly in MAC-T cells over 48 h. Transient and persistent strains displayed heterogeneous serotypes and overall genotypes, but similar phylogeny (group A), and lacked virulence genes of invasive E. coli. We have found that E. coli strains associated with persistent IMI are better able to invade and replicate within cultured mammary epithelial cells than transient strains. The invasion process involves the host cytoskeleton and signaling cascades and is not FimH dependent. Our findings suggest that the invasion of mammary epithelial cells and intracellular survival play an important role in the pathogenesis of persistent E. coli mastitis.     

Preliminary assessment of dietary mannanoligosaccharides on growth performance and health status of gilthead seabream Sparus auratus

A feeding trial was performed to assess the potential beneficial effect of two levels of mannanoligosaccarides (MOS) on the growth performance, feed utilization, hematological parameters, and liver histopathology of gilthead seabream Sparus auratus (also known as gilthead bream). Mannanoligosaccarides were added at the rates of 2 and 4 g/kg to a fish-meal-based control diet, and each diet was given (twice daily [midmorning and midafternoon] to apparent satiation) to triplicate groups of gilthead seabream growers (mean weight = approximately 170 g) in sea cages. The trial lasted 12 weeks, and the average ambient water temperature ranged from 19.6 degrees C to 24.7 degrees C during the experimental period. At the end of the experiment, fish attained market size (350-450 g) and their health status was evaluated by blood analysis and liver histology. There were no differences in survival rates among fish fed experimental diets. However, there were significant improvements in both growth and feed utilization among fish fed diets supplemented with MOS. Hemoglobin (Hb) and hematocrit (Ht) levels and erythrocyte, leukocyte, and thrombocyte (Thr) counts were unaffected by any dietary MOS. The levels of Hb (g/dL; mean +/- SD) and Ht (%; mean +/- SD) were 11.0 +/- 2.5 and 45.6 +/- 6.7 for the control group, 11.1 +/- 1.7 and 39.3 +/- 8.0 for the 2-g/kg group, and 11.2 +/- 1.9 and 40.2 +/- 8.4 for the 4-g/kg group. The mean Thr count ranged from 47.6 to 53.8 x 10(3)/mm3. Despite the apparently higher Thr counts for fish fed diets supplemented with MOS, these differences were not significant. Moreover, no histopathological differences were observed in liver tissue cross sections between control and treatment groups. These results suggest that supplementation of diets with MOS had no significant effects on general fish health.