Modeling the effects of Bunium persicum [Black Zira] essential oil, pH, inoculums size and temperature on the growth of Listeria monocytogenes

Listeriosis is acknowledged as a major foodborne disease throughout the world caused by Listeria monocytogenes. Different factors can affect the growth of food borne microbial pathogens. The aim of this study was to investigate the combined effects of different concentrations of Bunium persicum essential oil [EO] [0%, 0.08%, 0.16%, 0.24%], three incubation temperatures [35ºC, 25ºC, 4ºC], three levels of pH [5, 6, 7] and two inoculum sizes [103 and 105 cfu ml-1] on the growth of Listeria monocytogenes in brain heart infusion [BHI] broth. To evaluate effects of explanatory variable on time to detection [TTD] of bacterial growth, parametric survival models based on the log normal distribution were used. All explanatory variables had significant association with TTD [P<0.05]. The final model accurately predicted the growth initiation and inhibition of L. monocytogenes. Key words: Listeria monocytogenes, Black Zira essential oil, Time to detection, Modeling

Relationship between in vitro antimicrobial sensitivity of bovine subclinical mastitis isolates and treatment outcome in lactating dairy cows

The objective of the present study was to determine whether there was an association between in the in vitro antimicrobial sensitivity test results of subclinical mastitis pathogens and bacteriological cure following intramammary treatment using a combination of nafcillin, penicillin, and streptomycin [NPS]. Eighty-six intramammary pathogens from 43 cows were examined in this study. Most intramammary infections were due to coagulase-negative staphylococci, coliforms, and environmental streptococci. The antibiotic sensitivity to NPS was determined using the Kirby-Bauer disc diffusion method. Bacteriological cure rates for sensitive, intermediate, and resistant isolates in the standard treatment group [3 intramammary infusions of NPS once daily] were 84.44, 88.9, and 100%, respectively. These figures in the extended treatment group [6 intramammary infusions of NPS once daily] were 100% for the 3 categories. Bacteriological cure was not associated with the sensitivity test result. Based on this study, Kirby-Bauer sensitivity test results were not useful as predictors of the bacteriological outcome of subclinical mastitis treated with intramammary NPS

Conventional and extended intramammary therapy of persistent subclinical mastitis using nafcillin-pencillin-dihydrostreptomycin in lactating dairy cattle

The objective of the present study was to compare the efficacy of conventional and extended intrammamary [IMM] therapy of persistent subclinical mastitis in lactating dairy cattle using nafcillin-penicillin-dihydrostreptomycin combination [NPD]. Sixty-five dairy cows with 126 infected quarters were enrolled in the study. Infected cows were allocated randomly to 1 of 3 different treatment regimens: [1] conventional group: NPD administered IMM 3 times at 24-h intervals [20 infected cows, 43 intramammary infections [IMI]], [2] extended group: NPD administered IMM 6 times at 24-h intervals [23 cows, 43 IMI], and [3] untreated control group [22 cows, 40 IMI]. The overall bacteriological cure [BC] rates for subclinical IMI were 86.04%, 100%, and 20% for the conventional, extended and the control groups, respectively; indicating a higher BC rate [P<0.0001] for the treated groups than the control group. Significant difference [P=0.029] concerning the BC rate was also observed between the extended and the conventional groups. Significant difference [P=0.0021] in somatic cell count [SCC] was detected between the extended and the conventional groups. Significant difference [P=0.0021] in somatic cell count [SCC] was detected between the extended and the control group. Fat percentage increased in the conventional [P=0.029] and in the extended [P<0.0001] groups, and protein percentage increased only in the extended group [P=0.0016]. There was no significant difference in posttreatment milk production between the groups [P>0.05]. Results of this study indicate that NPD therapy was effective in eliminating subclinical IMI in lactating dairy cows, and that extended therapy enhanced BC rate and reduced SCC

Relationship between in vitro susceptibility of bovine subclinical mastitis isolates and bacteriological outcome of intramammary treatment with cefquinome

The objective of the present study was to determine whether there was an association between the in vitro antimicrobial susceptibility test results of subclinical mastitis pathogens and bacteriological outcomes of intramammary treatments using cefquinome. A total of 110 intramammary pathogens from 51 cows were assessed in this study. Most intramammary infections were due to coagulase-negative staphylococci, environmental streptococci, and coliforms. The antimicrobial susceptibility to cefquinome was determined using the Kirby-Bauer disc diffusion method. Bacteriological cure rates for the sensitive, intermediate, and resistant isolates in the standard treatment group [three intramammary infusions of 75 mg cefquinome at 16 h intervals] were 82.4%, 90%, and 87.5%, respectively. These figures in the extended treatment group [six intramammary infusions of 75 mg cefquinome at 16 h intervals] were 83.3%, 100%, and 100%, respectively. Treatment outcomes were not associated with the results of sensitivity tests in the standard group. However, in the extended group, the probability of a bacteriological cure was lower in quarters from which cefquinome-sensitive pathogens were isolated than the quarters from which intermediate or resistant pathogens were isolated. Based on this study, the Kirby-Bauer susceptibility test result is a poor predictor for the bacteriological cure of subclinical mastitis treated with intramammary cefquinome

[Study on possible relationship between gastric ulcer and cardiac arrhythmias in the Arab horse and Caspian miniature horse]

Peptic ulcer is a very common disorder in horse race and foals. In the present research possible relationship between gastric ulcer and the prevalence of cardiac arrhythmia were studied in two different horse race. In this respect. 13 Caspian miniature horses and 8 Arab horses were studied. Gastric ulcers and cardiac arrhythmias were diagnosed in 13 horses [62%] and 12[57%] out of 211 horses, respectively. The observed cardiac arrhythmias were sinus tachycardia, sinus bradycardia, sinus arrhythmia, second degree AV block and SA block. There was no significant relationship between gastric ulcer and cardiac arrhythmia in general and between gastric ulcer and each kind of arrhythmia [p>0.005]. Serum calcium, potassium. sodium, magnesium and inorganic phosphorous concentrations were measured in the horses. No significant correlation was seen between serum electrolyte and gastric ulcer or cardiac arrhythmia. Despite lack of significant correlation between cardiac arrhythmia and gastric ulcer, more occurrence for some kinds of arrhythmia in affected horses with gastric ulcer was very interesting and need to be further investigated in future

Gastric ulceration in Persian Arab horses in Iran: frequency, haematology and biochemistry

Gastric endoscopy was performed in the 24 Persian Arab horses from several race training in Tehran and Tabriz for detection of gastric ulcer. Gastric ulcer was evident in 14 Persian Arab horses [58.3%]. Ten out of 14 ulcers were in nonglandular region of the stomach. The horses with the history of long term treatment with non-steroidal anti-inflammatory drugs [NSAIDs] had high prevalence of the gastric ulcer in the glandular mucosa. In this study the prevalence of gastric ulceration was higher in horses with active training program than others. Twelve out of 14 [71%] horses with gastric ulcers had a history of active training. The difference of two groups in respect to training was not statistically significant [P>0.05]. The number of monocytes was significantly lower and concentrations of potassium were significantly higher in horses with gastric ulcer [P<0.05]. The results of this study showed that the frequency of gastric ulceration in the training Persian Arab horses was relatively high. Further studies are required to evaluate the clinical importance of ulcer in these horses

Growth limits of Staphylococcus aureus as a function of temperature, acetic acid, NaCI concentration, and inoculum level

Staphylococcus aureus is one of the most prevalent causes of gastroenteritis worldwide. Knowing the precise boundary for the growth/no growth interface of S. aureus and also determining the period of time needed for bacterial growth initiation is necessary for food safety risk assessment. This study was designed to examine the combined effects of temperature, acetic acid, inoculum level and NaCI concentration on the growth of S. aureus in brain heart infusion broth. Growth was monitored by visible turbidity over a 20 days period. Statistical analysis of data showed significant effects for selected parameters on growth of S. aureus. Stepwise multiple regression was used to predict the growth initiation [R[2] = 0.91, P<0.0001]. To obtain a boundary model, logistic regression was used. The models accurately predicted the growth initiation and inhibition of S. aureus

Effects of oral iron supplementation on haematocrit, live weight gain and health in neonatal dairy calves

Forty neonate calves were used in this study. The animals were divided into two treatment [n 20] and control [n = 20] groups. In the treatment group, oral iron as ferrous sulphate was supplemented to each calf at the dose of 150 mg/day for 28 days, from the birthday. Blood sampling was taken from jugular vein immediately after birth and on days 7, 14, 21 and 28 after birth. Significant differences in haematocrit [PCV] levels were found between two groups on days 14, 21 and 28 [P < 0.05]. Total gain, mean daily gain and weight gain during 4th week of life was significantly higher in the treatment group than control group [P

Relationships between fertility, serum calcium and inorganic phosphorus in dairy cows

A prospective study was conducted to investigate the difference in levels of some blood constituents between fertile and infertile cows, A total of 40 dairy cows were selected at random from a dairy farm. Serum samples were collected three times on 5 +/- 3, 30 +/- 3 and 58 +/- 3 days postpartum. Serum glucose, urea nitrogen [UN], cholesterol, albumin, total protein, calcium, inorganic phosphorus and aspartate aminotransferase [AST] were measured for each sample. Cows were divided into two categories; those which conceived at either the first or second insemination [group 1] and those which conceived >/= 3 inseminations [group 2]. Seventy percent [28 of 40] of the cows conceived at first or second insemination and 30% [12 of 40] needed 3 or more inseminations. Results showed that calcium [2.34 vs. 2.17 mmol/L] and inorganic phosphorus [1.84 vs. 1.42 mmol/L] were significantly [P<0.05] higher in the group 1 cows at second stage of sampling

[ case report of atrial fibrillation associated with left displacement of abomasum in a cow]

A three years old Holestein cow was admitted to large animal clinic of Tehran faculty of veterinary medicine with inappetence and decreased milk yield. Physical examination showed increased respiratory rate and irregular heart beats. The rumen was hypotonic and tympanitic resonance sound [ping] was heard on the upper half of 11-13 ribs in the left side. Left side displacement of abomasums was diagnosed and because of irregular heart beats, ECG was recorded by using a base apex lead. Irregular R-R intervals absence of P waves and presence of F waves were seen on the ECG. Atrial fibrillation as a secondary complication to displaced abomasums was diagnosed. The displaced abomasums corrected by bilateral laparatomy. Atrial fibrillation is usually a secondary condition due to gastrointestinal disorders in cattle and treatment of primary disease can eliminate atrial fibrillation