Sabry A. El-Khodery

Molecular screening and risk factors of enterotoxigenic Escherichia coli and Salmonella spp. in diarrheic neonatal calves in Egypt

Abstract The aim of the present study was to carry out molecular epidemiological investigation on enterotoxigenic Escherichia coli (ETEC) K99 and Salmonella spp. in diarrheic neonatal calves. Fecal samples were obtained from 220 diarrheic calves at 9 farms related to four governorates in central and northern Egypt. E. coli and Salmonella spp. isolates were examined for E. coli K99 and Salmonella spp. using PCR. ETEC K99 was recovered from 20 (10.36 %) out of 193 isolates, whereas Salmonella spp. was recovered from nine calves (4.09%). Multivariable logistic regression was used to evaluate the risk factors associated with both infections. ETEC K99 was significantly affected by age (P <0.01; OR: 1.812; CI 95%: 0.566–1.769), colostrum feeding practice (P <0.01; OR: 5.525; CI 95%: 2.025–15.076), rotavirus infection (P <0.001; OR: 2.220; CI 95%: 0.273–1.251), vaccination of pregnant dams with combined vaccine against rotavirus, coronavirus and E. coli (K99) (P <0.001; OR: 4.753; CI 95%: 2.124–10.641), and vitamin E and selenium administration to the pregnant dam (P <0.01; OR: 3.933; CI 95%: 0.703–1.248). Infection with Salmonella spp. was found to be significantly affected by the animal age (P <0.05; OR: 0.376; CI 95%: 0.511–1.369), Hygiene (P <0.05; OR: 0.628; CI 95%: 1.729–5.612), and region (P <0. 01; OR: 0.970; CI 95%: 0.841–1.624). The results of the present study indicate the importance of PCR as rapid, effective and reliable tool for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrhea may be helpful for construction of suitable methods for prevention and control.

Genetic analysis of antimicrobial resistance in Escherichia coli isolated from diarrheic neonatal calves.

This study was carried out to screen and analyze the genetic basis of antimicrobial resistance in Escherichia coli strains isolated from neonatal calf diarrhea in Egypt. A total of 182 isolates of E. coli recovered from 91 diarrheic neonatal calves were analyzed for antimicrobial susceptibilities, the presence of class 1 and class 2 integrons and antimicrobial resistance genes. Nineteen isolates (10.4%) showed multidrug resistance phenotypes and harbored at least three antimicrobial resistance genes. PCR screening detected class 1 integrons in 19 isolates (10.4%) and class 2 integrons in 2 isolates (1.1%). The identified antimicrobial resistance genes within class 1 integrons were dihydrofolate reductase types: dfrA1, dfrA12, dfrA15 and dfrA17, which confer resistance to trimethoprim; aminoglycoside adenyltransferase types: aadA1, aadA2, aadA5, aadA7 and aadA23, which confer resistance to streptomycin and spectinomycin; and aminoglycoside acetyltransferase gene, aac(3)-Id, which confers resistance to gentamicin and sisomicin. Furthermore, many beta-lactamases encoding genes, plasmid-mediated quinolone resistance genes and florfenicol resistance gene were identified in this study. To the best of our knowledge, this is the first report for molecular characterization of antimicrobial resistance in E. coli isolated from diarrheic neonatal calves in Africa.

Acute coliform mastitis in buffaloes (Bubalus bubalis): Clinical findings and treatment outcomes

This report was delineated to study the clinical, bacteriological and therapeutic aspects concerned with acute coliform mastitis in buffaloes. Bacteriological examination of 80 quarter milk samples obtained aseptically from 56 buffaloes with acute mastitis revealed that coliform bacteria was the most common pathogen (45 cases) followed by Staphylococcus aureus (seven cases) then Streptococcus uberis (three cases), and Streptococcus agalactiae (one case). Clinically, hotness, swelling and painful reaction with serous excretion containing clots was recorded in buffaloes with coliform mastitis. The efficacy of ceftiofur was evaluated in the treatment of buffaloes with acute coliform mastitis. Parenteral ceftiofur neither improved clinical signs nor returned milk to pre-infection production level, whereas intramammary ceftiofur and combination of intramammary with parenteral ceftiofur improved the clinical signs in 10/15 and 12/15 buffaloes, respectively. On quarter level, 3/17, 12/17 and 15/21 quarters recovered in groups received parenteral, intramammary and combination therapy, respectively. This study demonstrates that systemic ceftofur is not effective in the treatment of clinical coliform mastitis in buffaloes.

Optimization of a Fluorescence-Based Assay for Large-Scale Drug Screening against Babesia and Theileria Parasites

A rapid and accurate assay for evaluating antibabesial drugs on a large scale is required for the discovery of novel chemotherapeutic agents against Babesia parasites. In the current study, we evaluated the usefulness of a fluorescence-based assay for determining the efficacies of antibabesial compounds against bovine and equine hemoparasites in in vitro cultures. Three different hematocrits (HCTs; 2.5%, 5%, and 10%) were used without daily replacement of the medium. The results of a high-throughput screening assay revealed that the best HCT was 2.5% for bovine Babesia parasites and 5% for equine Babesia and Theileria parasites. The IC50 values of diminazene aceturate obtained by fluorescence and microscopy did not differ significantly. Likewise, the IC50 values of luteolin, pyronaridine tetraphosphate, nimbolide, gedunin, and enoxacin did not differ between the two methods. In conclusion, our fluorescence-based assay uses low HCT and does not require daily replacement of culture medium, making it highly suitable for in vitro large-scale drug screening against Babesia and Theileria parasites that infect cattle and horses.

Seroprevalence of camel brucellosis (Camelus dromedarius) in Somaliland.

The present study was delineated to investigate the prevalence and risk factors of camel brucellosis in Northern Somalia (Somaliland). The study was carried out at three main districts of camel-rearing regions of Somaliland (Awdal, Waqoyi Galbed and Togdheer) in the period from July to November, 2008. A total of 1246 camel blood sera were randomly collected from 42 sporadic small scale camel herds. Two serological tests were used to screen all serum samples, Rose Bengal Plate Test (RBPT) and indirect ELISA (I-ELISA). Multivariate logistic regression was constructed to study the risk factors associated with Brucella seropositive cases. The overall prevalence of camel brucellosis in districts under investigation was 3.9% by RBPT and 3.1% by (I-ELISA). Multivariate logistic regression on animal level showed that locality (P < 0.05; OR: 6.254; CI, 1.186–32.976), herd size (P < 0.001; OR: 5.493; CI, 2.956-10–207), rearing with other ruminants (P < 0.001; OR: 12.433; CI, 3.957–39.060), and contact with other camels (P < 0.05; OR: 5.311; CI, 1.093–25.800) were the potential risk factors. However, herd size (P < 0.05; OR: 5.425; CI, 1.181–24.932), and rearing with other ruminants (P < 0.05; OR: 20.466; CI, 1.456–28.638) were recorded as risk factors on the herd level. The results of the present investigation indicate that the Brucella spp. exists within the camel herds in Somaliland. Further studies need to be done on Brucella infection in the other ruminants to determine which measure should be followed for control of brucellosis.

Ketosis in buffalo (Bubalus bubalis): clinical findings and the associated oxidative stress level

As little is known about the oxidant/antioxidant status in buffalo with ketosis, the present study was delineated to assess the oxidative stress level associated with clinical ketosis in water buffalo. A total of 91 parturient buffalo at smallholder farms were studied (61 suspected to be ketotic and 30 healthy). Clinical and biochemical investigations were carried out for each buffalo. Based on clinical findings and the level of beta-hydroxybutyrate (BHB), buffalo were allocated into ketotic (42), sublinical cases (19). Clinically, there was an association between clinical ketosis and anorexia (p < 0.001), constipation (p < 0.001), decreased milk yield (p < 0.001), ruminal stasis (p < 0.001), and loss of body condition (p < 0.01). Biochemically, in clinical ketosis compared with subclinical and control cases, there was a significant increase (p < 0.05) of BHB, malondialdehyde (MDA), nitric oxide (NO), aspartate aminotransferase (AST), L-alanine aminotransferase (ALT). However, there was a significant decrease of glucose, phosphorus, magnesium,total cholesterol and HDL-cholesterol. There was a positive correlation between BHB and MDA (r = 0.433), BHB and NO (r = 0.37), MDA and NO (r = 0.515), and Glucose and phosphorus(r = 0.521). However, there was a negative correlation between BHB and glucose (r = −0.341) and HDL and NO (r = −0.379). The result of the present study indicates that hyperketonemia in buffalo is associated with an increase of oxidative stress levels. Further studies need to be done on the efficacy of antioxidants as an ancillary treatment to relief the oxidative stress caused by ketosis.

Effect of intravenous administration of romifidine on intraocular pressure in clinically normal horses

OBJECTIVE To evaluate the effect of intravenous administration of romifidine on the intraocular pressure (IOP) in horses. ANIMALS STUDIED Twenty-four horses with no ocular abnormalities. PROCEDURE Horses were randomly assigned into two equal groups (treatment and control). All horses in the treatment group received an intravenous (IV) injection of romifidine (40 μg/kg). The horses in the control group were administrated an intravenous injection of 0.9% saline (0.4 mL/100 kg). In both groups, the IOP values were measured immediately (T0 ) pre-administration and at 5 (T5 ), 15 (T15 ), 30 (T30 ), 45 (T45 ), 60 (T60 ), 90 (T90 ), and 120 (T120 ) min after drug administration. RESULTS The pre-treatment values (T0 ) of IOP for right and left eyes were 24.25 ± 3.5 and 25.16 ± 3.4 mmHg, respectively. A significant decrease in IOP values was observed in both right and left eyes of the horses in treatment group at T5 , T15 , T30 , T45 , T60 , and T90 in comparison with the baseline values (P < 0.05). The lowest level of IOP in romifidine-treated groups was recorded at T45 for the right and left eyes (10.25 ± 2.3 and 11.25 ± 3.5 mmHg, respectively). CONCLUSION Romifidine significantly decreased IOP in clinically normal horses and may be used safely for surgery or diagnostic ocular procedures in horses when specific control of IOP is required.

Antioxidant Trace Elements in Serum of Draft Horses with Acute and Chronic Lower Airway Disease

The aim of the present study was to evaluate the oxidative stress level and antioxidant trace elements status associated with lower airway disease in draft horses. For this purpose, venous blood samples were obtained from draft horses exhibiting signs of lower respiratory tract disorders (n = 83) and from control group (n = 20). Serum trace elements including selenium (Se), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) were assayed. Serum malondialdehyde (MDA) and low-density lipoprotein (LDL) levels as well as plasma hydrogen peroxides (H2O2) concentration and activity of plasma glutathione reductase (GR), glutathione-S-transferase (GST) and catalase (CAT) were measured. There was a significant (p < 0.05) decrease of Se, Cu, Zn, and Fe in diseased horses compared with healthy ones, but the Cu/Zn ratio and Mn were increased (p < 0.05). Se was significantly (p < 0.05) decreased in chronically affected horses compared with acute cases, but Mn was increased (p < 0.05). There was an increase of MDA, LDL, and H2O2 levels and GR activity in diseased cases compared with healthy horses. However, there was a significant (p < 0.05) decrease of GST and CAT activity. MDA and LDL levels were increased (p < 0.05) in horses with chronic respiratory disease compared to acute cases, but CAT activity was decreased (p < 0.05). In horses with acute lower airway disease, there was a negative correlation between GR and H2O2 (r = −0.458), and LDL and CAT (r = −0.816). However, in chronic disease, a negative correlation was recorded between Se and MDA (r = −0.590). The results of the present study indicate that oxidative stress, with alteration of antioxidant trace element levels, is a feature of respiratory disease in draft horses.

Risk factors of infestation by Psoroptes spp. mites in buffalo (Bubalus bubalis) at smallholder farms in the Nile Delta region, Egypt.

The aim of the present study was to explore the prevalence and potential risk factors associated with infestation by Psoroptes spp. mites in buffalo at smallholder farms in the Nile Delta region, Egypt. A total of 318 out of 1234 buffalo in 77 small scale herds were examined. The age of buffalo varied from three months to seven years. In all, 53 (16.66%) buffalo were recorded to be infested; 51 (16.35%) with Psoroptes spp. mites and two cases (0.31%) with Chorioptes spp. mites. Multivariate logistic regression was performed for significant risk factors at univariate analysis on both animal and herd level. The results of multivariate analysis showed that, on the animal level, the prevalence was affected by animal age (P < 0.01; OR: 0.71; CI 95%: 0.441–1.11), season (P < 0.01; OR: 1.20; CI 95%:0.541–1.15), indoor management (P < 0.001; OR: 6.625; CI 95%:2.489 –17.631) and rearing with other animals (P < 0.01; OR: 2.22; CI 95%:1.340 –7.132). However, on the herd level, the prevalence was affected by indoor rearing (P < 0.05; OR: 22.4; CI 95%:2.75–16.431), mixed rearing with other animal species (P < 0.05; OR: 4.5; CI 95%:1.66–7.941), and season (P < 0.01; OR: 2.3; CI 95%:0.575–2.426). Clinically, mild skin lesions with mild pruritis were significantly prevalent in buffalo with the infestation by Psoroptes spp. mites (P < 0.001), where 33/51 cases showed mild lesions. Also, psoroptic mites had significant association with inappitence (P < 0.001). The result of the present study indicates that Psoroptes spp. mites are the most prevalent in buffalo in the Nile Delta Region, Egypt. Moreover, recognition of risk factors associated with mange mites in buffalo may enable the practitioner to establish the most appropriate control measures.

Sedative and analgesic effects of romifidine in camels (Camelus dromedarius).

OBJECTIVE To evaluate the clinical effectiveness and the sedative and analgesic effects of intravenous (IV) romifidine in camels. STUDY DESIGN Randomized prospective study. ANIMALS Eighteen healthy adult Dromedary camels. METHODS Romifidine was administered IV to camels (n = 6) at three different doses (40, 80 or 120 microg kg(-1)). Time of onset, degree and duration of sedation and analgesia were recorded immediately after drug administration. Heart rate, respiratory rate, ruminal contractions, muscle relaxation, response to auditory and tactile stimulation, distance between ears, distance from lower lip to the ground, and degree of ataxia were also recorded pre-administration and at 5, 15, 30, 45, 60, 90, 120 and 180 minutes post-administration. Plasma glucose, blood urea nitrogen and creatinine were measured. RESULTS Romifidine produced dose dependent sedation and analgesia. Significant decreases in heart rate (p < 0.001), ruminal contractions (p < 0.05), distance from lower lip to the ground (p < 0.001), response to auditory and tactile stimuli (p < 0.01), and significant increases in the degree of ataxia (p < 0.01), distance between the ear tips (p < 0.001) and blood glucose (p < 0.01) concentration were recorded after administration of romifidine until recovery. However, no significant changes in rectal temperature and respiratory rate were recorded. CONCLUSIONS AND CLINICAL RELEVANCE Intravenous administration of romifidine at three different doses appeared to be an effective sedative and analgesic agent for camels. Bradycardia, ruminal atony, and hyperglycemia were the most important adverse effects after IV administration of romifidine. The IV administration of romifidine at a dose rate of 120 microg kg(-1) caused profound sedation and analgesia. Romifidine could be used for chemical restraint for a variety of diagnostic and minor surgical procedures in camels.