Efficacies of liposome-encapsulated enrofloxacin against Staphylococcus aureus infection in Anatolian shepherd dog monocytes in vitro.

The aim of this study was to evaluate the intracellular activity of two types of liposome-encapsulated enrofloxacin (LE) compared with free enrofloxacin and non-treated control against Staphylococcus aureus, phagocytosed by monocytes in healthy Anatolian Shepherd dogs. Enrofloxacin was encapsulated with two different types of liposome in multilamellar large vesicles (MLV). Type A MLV were composed of 15 mg phosphatidylcholine and 35 mg cholesterol, Type B MLV were composed of phosphatidylcholine, cholesterol and enrofloxacin in a molar ratio of 1:1:1. Intracellular activity was estimated by comparing the numbers of bacteria surviving intracellularly in monocytes exposed to free enrofloxacin and LE for 4 h at the doses of 0.25, 0.5 and 1 microg/ml, with those surviving intracellularly in untreated control monocytes. All three forms of enrofloxacin (free, Type A and B liposomes) increased the intracellular killing of S. aureus in a concentration dependent manner. Comparison of 1 microg/ml Type B LE revealed that killing activity was significantly higher than those of other concentrations. The results showed that LE was superior in reducing the number of intracellularly located bacteria compared to the free drug and control. The beneficial effect of liposomal encapsulation is presumably due to the fact that both liposomes and bacteria are localized at the same spot in phagocytic cells.

Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile (Crocodylus niloticus).

Aeromonas hydrophila is one of the most common bacteria associated with the aquatic environment. There are, however, limited data on A. hydrophila infection in crocodilians. The aim of this report is to describe a case of skin lesions and septicaemia associated with A. hydrophila in a Nile crocodile (Crocodylus niloticus). A captive male crocodile in the Zoological Park of Antalya (Turkey) was found dead without showing signs of any disease. Gross examination showed brown or red-spotted skin lesions of varying size. These lesions were mostly scattered over the abdomen and occasionally on the tail and feet. At necropsy, numerous white, multifocal and randomly distributed areas were seen on the liver. Gram-stained smears from skin and liver lesions showed Gram-negative bacilli arranged in clusters. Pure cultures of A. hydrophila were recovered from skin, internal organs and blood. Isolates were found to be susceptible to ceftiofur, amoxicillin + clavulanic acid, oxytetracycline, enrofloxacin, danofloxacin, neomycin, gentamicin, and lincomycin + neomycin. A pathogenicity test was performed using this isolate on 4 male 2-year-old New Zealand white rabbits. Local abscesses formed in 2 rabbits injected subcutaneously and the 2 that were injected intraperitoneally died as a result of septicaemia. In conclusion, this report has shown that A. hydrophila may cause skin lesions and even death due to septicaemia in crocodiles.

A comparative study on detection of Ornithobacterium rhinotracheale antibodies in meat-type turkeys by dot immunobinding assay, rapid agglutination test and serum agglutination test.

The objectives of the present study were to develop a dot-immunobinding assay (DIA) and a serum agglutination test (SAT) for detection of Ornithobacterium rhinotracheale, to compare the rapid agglutination test (RAT) and the SAT, and to make a serosurvey of O. rhinotracheale exposure on turkey farms in Turkey. Antiserum against O. rhinotracheale bacterin was prepared in rabbits and 72 serum samples were collected from turkeys with respiratory signs on four farms. Comparison of the tests showed that 55.5, 48.6 and 40.3% of serum samples were positive by RAT, SAT and DIA, respectively. The sensitivity of the DIA appeared to be lower than that of the agglutination tests but the specificity is not known.

Determination of intracellular concentrations of free and two types of liposome-encapsulated enrofloxacin in anatolian shepherd dog monocytes.

In this study, it was evaluated the accumulation of free and two types of liposome-encapsulated enrofloxacin (LEE) at the doses of 0.25, 0.5 and 1 microg/ml, which were clinically relevant concentrations into monocytes of healthy Anatolian shepherd dogs. Enrofloxacin was encapsulated with two different types of liposome in multilamellar large vesicles (MLV). Type A MLV composed of 15 mg egg phosphatidylcholine and 35 mg cholesterol, Type B MLV composed of phosphatidylcholine (PC), cholesterol and enrofloxacin, in a molar ratio of 1 : 1 : 1. The mean sizes of Type A and Type B liposome were found to be 7.65 and 4.27 microm, respectively. However, the mean encapsulation rate determined of Type A (13 +/- 2%) was found lower than Type B liposome (44 +/- 3%). The amounts of intracellular enrofloxacin concentrations were determined by high performance liquid chromatography. Type B LEE accumulated significantly higher level into monocytes when compared to free drug or Type A liposome. This study showed that Type B LEE markedly concentrated within monocytes and may improve the antibacterial efficacy of the antibiotic.

Clinical efficacy of florfenicol in the treatment of calf respiratory tract infections.

This paper reports on a study of the aetiology of calf pneumonia and the clinical efficacy of florfenicol, a new antibiotic in Turkey. Twenty-seven weaned and unweaned calves (13 males and 14 females) between 1 and 16 months of age brought to the clinics of Selçuk University, Faculty of Veterinary Science. Broncho-alveolar lavage (BAL) fluid samples were taken from the animals diagnosed to have upper respiratory tract infection associated with bronchitis (N=2), bronchitis (N=5), bronchopneumonia (N=4), pneumonia (N=3), pleuropneumonia (N=11), bronchopneumonia plus pulmonary oedema (N=2) based on the results of the clinical and laboratory examinations. Then microbiological isolation and antibiotic culturing were performed. The animals were treated with 1 ml/15 kg (20 mg/kg) florfenicol (Nuflor, DIF) twice within 48 hours via intramuscular injection. At the end of the treatment, 23 of the weaned and unweaned calves were completely healed, 1 calf had died and 3 calves showed no healing. The results of BAL samples and microbiological examinations of the 3 calves that did not respond to the treatment indicated that these cases were affected by mixed infections of yeasts, fungi, and bacteria. Widespread pleuropneumonia was observed. According to the results of the microbiological examination of the BAL samples, Mannheimia (Pasteurella) haemolytica had the highest isolation rate (25%) compared with the other isolated bacteria, namely, Klebsiella pneumonia (20%), Actinomyces pyogenes (15%), beta-hemolytic streptococci. (10%), Staphylococcus spp. (5%), and E. coli (5%). The study also revealed fungi [Penicillum spp. (5%) and Aspergillus spp. (5%)] and two calves (10%) had a yeast infection.. We conclude that florfenicol has a high bacteriological and clinical efficacy (100% and 96% respectively) in the treatment of calf respiratory tract diseases.

Hemagglutination, hydrophobicity, enterotoxigenicity, and drug-resistance characteristics of avian Escherichia coli.

A total of 35 Escherichia coli isolates obtained from necropsy materials of hens with septicemia in the Konya region of Turkey were examined for hemagglutination (HA), cell-surface hydrophobicity, enterotoxigenicity, and drug resistance. HA tests were performed on live cultures with human (group A), bovine, avian (chicken), and guinea pig erythrocytes with and without mannose. Nine HA patterns were observed. Of the 35 isolates, 62.8% exhibited mannose sensitive hemagglutination (MSHA), 8.6% exhibited mannose resistant hemagglutination (MRHA), and 28.6% did not hemagglutinate. Of the isolates, 85.7% were hydrophobic by a salt aggregation test (SAT). Only three isolates were enterotoxigenic by a suckling mouse assay. The majority of the isolates were resistant to chloramphenicol, tetracycline, streptomycin, ampicillin, erythromycin, and trimethoprim + sulfamethoxazole but were highly sensitive to gentamicin and nalidixic acid.

Isolation of Acinetobacter lwoffi from hens with septicemia.

Acinetobacter lwoffi was isolated from the lungs of two hens. The isolate was sensitive to chloramphenicol, ampicillin, erythromycin, oxytetracycline but resistant to penicillin and nitrofurantoin.