禽大肠杆菌和沙门氏菌混感的诊断与药敏试验

利用采自莱芜市某发病鸡场的病料,研究其致病原因并进行药敏试验。通过运用细菌分离培养鉴定、生化试验来鉴别分离自发病鸡群的致病菌。对采自发病鸡群的细菌进行药物敏感性试验。结果显示,分离自发病鸡群的细菌有2种,分别为大肠杆菌与沙门氏菌。大肠杆菌对头孢曲松与头孢噻肟中度敏感;沙门氏菌对头孢曲松、丁胺卡那中度敏感;对头孢噻肟、庆大霉素、安普霉素、强力霉素敏感。     

河南省副猪嗜血杆菌的分离鉴定与药敏试验

从河南省内不同县市的部分猪场送检疑似感染副猪嗜血杆菌病病料中分离鉴定到9株致病菌。为防治疾病传播,控制疫情蔓延,对分离菌株进行病理剖检、细菌分离培养、生化鉴定以及PCR鉴定和药敏试验。结果表明,分离到的致病菌为副猪嗜血杆菌。药敏试验显示9株分离菌株对氨苄西林、头孢噻呋、头孢他啶、氟苯尼考、阿奇霉素、阿莫西林高敏;对壮观霉素、左氟沙星、氧氟沙星、环丙沙星敏感;对克林霉素、阿米卡星、卡那霉素、恩诺沙星不敏感或耐药;对红霉素、罗红霉素、新霉素、四环素、强力霉素敏感性不稳定,表现不一。     

雏鸡绿脓杆菌的分离鉴定及药敏试验

对河南省中牟县某养殖户送检的病鸡进行病理剖检及细菌分离鉴定,根据发病临床症状,病理变化及病原分离鉴定,确诊为绿脓杆菌感染。药敏试验结果显示,所分离的绿脓杆菌对庆大霉素、氧氟沙星高度敏感;对丁胺卡那、多黏菌素中度敏感;对阿莫西林、氨苄西林及强力霉素耐药。     

规模化肉鸡场大肠杆菌的分离鉴定及药敏试验

对驻马店地区规模化肉鸡场所发疾病进行调查,根据临床症状、病理变化及病原分离鉴定结果,确诊为大肠杆菌病。选择10株分离菌进行药敏试验,结果表明,多数菌对利高霉素、头孢曲松、丁胺卡那霉素、新霉素、氧氟沙星敏感,敏感率分别为80%、60%、60%、60%、50%;对多黏菌素、氟苯尼考的敏感率分别为10%、20%;分离的10株菌对甲砜霉素、强力霉素、恩诺沙星、诺氟沙星、环丙沙星、链霉素、阿莫西林、氨苄青霉素、土霉素全部耐药。     

泉州洛江区鸡沙门氏菌的分离鉴定及药敏试验

对洛江区部分养殖场的发病鸡只进行沙门氏菌分离培养鉴定,并对分离菌株进行药敏试验。结果表明,分离的沙门氏菌对对恩诺沙星、阿米卡星最敏感,敏感率分别为100%、91.7%;其次为头孢克洛,敏感率为83.3%;对氟苯尼考、林可霉素、庆大霉素、泰妙菌素、替米考星、阿莫西林的敏感率范围较宽,为8.3%~41.7%;对强力霉素、阿奇霉素、青霉素、氨苄西林敏感率为零,产生耐药性。本研究为临床上科学选择有效药物用于预防控制鸡沙门氏菌提供了参考依据。     

致病性产H2S大肠杆菌和产气肠杆菌的分离与鉴定

为了研究某规模化猪场胀气死亡母猪的病原及筛选有效治疗药物,试验采用常规细菌分离培养方法,对其消化道进行致病菌分离、鉴定、动物攻毒试验和药敏试验。结果表明:从肠道内分离出2株细菌纯培养物,均为革兰阴性短杆菌,一株菌为H2S阳性大肠杆菌,另一株菌为产气肠杆菌;2株分离菌均可致死小白鼠。H2S阳性大肠杆菌对新霉素、新生霉素和痢特灵高度敏感,对哌拉西林和阿米卡星中度敏感,对其他药物低敏或不敏感;产气肠杆菌对阿米卡星高度敏感,对哌拉西林、链霉素、阿莫西林、新生霉素、痢特灵和强力霉素中度敏感,对其他药物低敏或不敏感。     

鸡源大肠杆菌的分离鉴定及药敏试验研究

本试验通过对大肠杆菌进行分离纯化、生化鉴定等步骤分离出三株大肠杆菌,再用肉汤稀释法对大肠杆菌进行药敏试验。结果表明,其中全部3株大肠杆菌都对硫酸庆大霉素、硫酸安普霉素、硫酸黏菌素、恩诺沙星、诺氟沙星、达氟沙星、左氧氟沙星、阿米卡星、环丙沙星、硫酸新霉素敏感。对大环霉素一株中度敏感,两株不敏感。对硫酸链霉素一株中度敏感,两株不敏感。其中全部的三株大肠杆菌对泰妙霉素耐药,而泰乐霉素则不起任何有效作用。     

秃鹫黏质沙雷氏菌和大肠杆菌的分离、鉴定及药敏试验

采集死亡秃鹫的心脏、肝脏病灶进行细菌分离鉴定、生化试验,其病原菌为沙雷氏菌和大肠杆菌;经药敏试验,大肠杆菌对环丙沙星、庆大霉素、氯霉素极度敏感,对头孢哌酮、头孢他啶、头孢吡肟高度敏感,对恩诺沙星中度敏感,对新生霉素、多黏菌素B、四环素低度敏感;黏质沙雷氏菌对头孢哌酮、头孢他啶、恩诺沙星高度敏感,对头孢吡肟、环丙沙星中度敏感,对庆大霉素、氯霉素、新生霉素、多黏菌素B、四环素低度敏感。采用对黏质沙雷氏菌和大肠杆菌均属高度敏感的药物头孢哌酮治疗患病秃鹫,陆续痊愈。     

六安地区猪链球菌分离鉴定及药敏学试验

笔者时采集的病料进行猪链球菌的分离、培养、镜检和鉴定,获得了15株链球菌,并进行了12种抗生素敏感试验,发现分离菌株对12种药物有不同程度的耐药性,其中,四环素、强力霉素、万古霉素、克林霉素等高度敏感,敏感率在90%以上;青霉素、链霉素、多黏菌素等敏感度低于40%.以上敏感药物则可作为防治猪链球菌的首选药物.     

雅安地区鸭沙门杆菌分离鉴定及耐药性分析

为了研究雅安地区鸭沙门杆菌的耐药性,试验对部分鸭场鸭所发生的疾病调查、采样,并进行生化鉴定和耐药性分析。结果表明:从200份样本中共分离出13株沙门杆菌;分离所得的沙门杆菌对丁胺卡那霉素、氟哌酸、新霉素、阿奇霉素、氟苯尼考等13种药物高度敏感,对青霉素、痢特灵、庆大霉素等5种药物较为敏感,对强力霉素和头孢氨苄这2种药物中度敏感,对氨苄西林、利福平、氯洁霉素、大观霉素等7种药物已产生了较强的耐药性。     

Pharmacokinetics after administration of an injectable experimental long-acting parenteral formulation of doxycycline hyclate in goats

OBJECTIVE: To determine the pharmacokinetics after SC administration of an experimental, long-acting parenteral formulation of doxycycline hyclate in a poloxamer-based matrix and after IV and IM administration of an aqueous formulation of doxycycline hyclate in goats. ANIMALS: 30 clinically normal adult goats. PROCEDURES: Goats were allocated to 3 groups (10 goats/group). One group of goats received doxycycline hyclate (10 mg/kg) IM, a second group received the same dosage of doxycycline hyclate IV, and the third group received the long-acting parenteral formulation of doxycycline hyclate SC. Serum concentrations of doxycycline were determined before and at various intervals after administration. RESULTS: The long-acting parenteral formulation of doxycycline hyclate had the greatest bioavailability (545%); mean +/- SD maximum serum concentration was 2.4 +/- 0.95 microg/mL, peak time to maximum concentration was 19.23 +/- 2.03 hours, and elimination half-life was 40.92 +/- 4.25 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the long-acting parenteral formulation of doxycycline hyclate distributed quickly and widely throughout the body after a single dose administered SC, and there was a prolonged half-life. Bioavailability of the longacting parenteral formulation of doxycycline hyclate after SC administration was excellent, compared with bioavailability after IV and IM administration of an aqueous formulation of doxycycline hyclate. Although no local tissue irritation and adverse effects were detected, clinical assessment of drug-residues and toxicologic evaluations are warranted before this long-acting parenteral formulation of doxycycline hyclate can be considered for use in goats with bacterial infections.     

The effect of sucralfate tablets vs. suspension on oral doxycycline absorption in dogs

The purpose of this study was to determine the effect of concurrent sucralfate (tablet or suspension) on doxycycline pharmacokinetics and to determine the effects of delaying sucralfate by 2 h on doxycycline absorption. Five dogs were included in a crossover study receiving: doxycycline alone; doxycycline concurrently with sucralfate tablet; doxycycline followed 2 h by sucralfate tablet; doxycycline concurrently with sucralfate suspension; and doxycycline followed 2 h by sucralfate suspension. Doxycycline plasma concentrations were evaluated with liquid chromatography with mass spectrometry. No interaction was seen when sucralfate was administered as a tablet. Sucralfate tablet fragments were frequently observed in some dogs' feces. The area under the curve (AUC) and maximum plasma concentration (C_MAX) were significantly lower (P < 0.001) in the concurrent sucralfate suspension group (AUC 7.2 h·μg/mL, C_MAX 0.43 μg/mL) than with doxycycline alone (AUC 36.0 h·μg/mL, C_MAX 2.53 μg/mL) resulting in a relative bioavailability of 20%. Delaying sucralfate suspension by 2 h after doxycycline administration resulted in no difference in doxycycline absorption as compared with doxycycline administration alone with a relative bioavailability of 74%. The lack of an interaction with sucralfate tablets suggests sucralfate should be administered as a suspension rather than tablet in dogs.     

Comparison of plasma and interstitial fluid concentrations of doxycycline and meropenem following constant rate intravenous infusion in dogs

OBJECTIVE: To compare plasma (total and unbound) and interstitial fluid (ISF) concentrations of doxycycline and meropenem in dogs following constant rate IV infusion of each drug. ANIMAL: 6 adult Beagles. PROCEDURE: Dogs were given a loading dose of doxycycline and meropenem followed by a constant rate IV infusion of each drug to maintain an 8-hour steady state concentration. Interstitial fluid was collected with an ultrafiltration device. Plasma and ISF were analyzed by high performance liquid chromatography. Protein binding and lipophilicity were determined. Plasma data were analyzed by use of compartmental methods. RESULTS: Compared with meropenem, doxycycline had higher protein binding (11.87% [previously published value] vs 91.75 +/- 0.63%) and lipophilicity (partition coefficients, 0.02 +/- 0.01 vs 0.68 +/- 0.05). A significant difference was found between ISF and plasma total doxycycline concentrations. No significant difference was found between ISF and plasma unbound doxycycline concentrations. Concentrations of meropenem in ISF and plasma (total and unbound) were similar. Plasma half-life, volume of distribution, and clearance were 4.56 +/- 0.57 hours, 0.65 +/- 0.82 L/kg, and 1.66 +/- 2.21 mL/min/kg, respectively, for doxycycline and 0.73 +/- 0.07 hours, 0.34 +/- 0.06 L/kg, and 5.65 +/- 2.76 mL/min/kg, respectively, for meropenem. The ISF half-life of doxycycline and meropenem was 4.94 +/- 0.67 and 2.31 +/- 0.36 hours, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The extent of protein binding determines distribution of doxycycline and meropenem into ISF. As a result of high protein binding, ISF doxycycline concentrations are lower than plasma total doxycycline concentrations. Concentrations of meropenem in ISF can be predicted from plasma total meropenem concentrations.     

双波长紫外分光光度法测定复方恩诺沙星可溶性粉中恩诺沙星和盐酸多西环素的含量

建立了复方恩诺沙星可溶性粉中恩诺沙星和盐酸多西环素含量的检测方法.采用双波长紫外分光光度法,直接测定两组分的含量.结果显示可同时测出复方恩诺沙星可溶性粉中恩诺沙星和盐酸多西环素的各自含量,且吸收度与各自的浓度成良好线性关系.恩诺沙星平均回收率为100.1%,RSD为0.04%(n=5).盐酸多西环素平均回收率为100.2%,RSD为0.14%(n=5).本方法简便、快速、可靠,可用于复方恩诺沙星可溶性粉的含量测定.     

Antimicrobial disposition in pulmonary epithelial lining fluid of horses, part II. Doxycycline

Doxycycline concentrations, following two types of oral administration to horses, in pulmonary epithelial lining fluid (PELF) were examined and compared to plasma concentrations. The oral bioavailability was estimated from plasma concentrations achieved after an intravenous study in two horses. Doxycycline (10 mg/kg) was administered either intragastric or as topdressing to nonfasted horses. Blood samples were collected for drug analysis, before and 11 times after administration during 24 h. PELF samples were collected by a tampon device four times after drug administration and analysed for doxycycline concentrations. Another two horses received doxycycline intravenously at a dose of 3 mg/kg and plasma was taken 14 times during a 24- h period. The oral bioavailability of doxycycline was calculated to 17% after intragastric administration and 6% after topdressing administration in nonfasted horses. The degree of penetration of doxycycline into PELF, as described by AUC(PELF) /AUC(plasma) ratios, was 0.87 after intragastric administration. The results indicate that clinically relevant doxycycline concentrations are possible to maintain in PELF after intragastric administration. Furthermore, if bioavailability could be enhanced for per os administration, doxycycline might be a valuable drug for the treatment of lower airway infections in horses.     

Degradation of doxycycline in aged pig manure

Two types of studies were carried out to characterise the degradation rate of doxycycline in manure. In the laboratory experiment, pig manure containing doxycycline was stored in biochemical oxygen demand (BOD) bottles in a thermoregulated room at a temperature of 20 ± 3.5 °C to maintain the humid and anaerobic incubation conditions, and the relevant temperature. In the field study, the traditional manure composting process used by small farms and household plots was demonstrated, in which the manure heap containing doxycycline was exposed to the regular environmental conditions. In the laboratory experiment more than 30% and in the field study about 10% of the initial doxycycline amount could be detected in manure samples after 16 and 12 weeks of manure ageing period, respectively. Based on the results obtained from the studies performed under laboratory and field conditions, the half-life of doxycycline in manure was calculated to be 52.5 and 25.7 days, respectively.     

双波长紫外分光光度法测定酒石酸泰乐菌素-盐酸多西环素可溶性粉的含量

建立了双波长紫外分光光度法同时测定酒石酸泰乐菌素-盐酸多西环素可溶性粉中酒石酸泰乐菌素和盐酸多西环素含量的检测方法。结果显示，吸收度与浓度呈良好线性关系。酒石酸泰乐菌素的平均回收率为99．90％，RSD为0．42％n=5）；盐酸多西环素的平均回收率为100．07％，RSD为0．74％（n=5）。     

Ocular penetration of oral doxycycline in the horse

OBJECTIVE: To investigate intraocular penetration of orally administered doxycycline in the normal equine eye and to compare intraocular and serum doxycycline concentrations. Procedures Six mares were administered doxycycline at 10 mg/kg every 12 h by nasogastric tube for 5 days. Blood, aqueous, and vitreous samples were collected on days 1 and 5. All samples were assayed for doxycycline concentrations. Aqueous and vitreous samples were also assayed for protein quantitation. RESULTS: Doxycycline was rapidly absorbed after the first dose (T(max) value of 1.42 +/- 1.28 h); and elimination of doxycycline occurred slowly (median t(1/2) = 10.88 h). Doxycycline could not be detected in the aqueous on days 1 and 5, nor could it be detected in the vitreous on day 1. On day 5, the mean vitreous doxycycline concentration was 0.17 +/- 0.04 microg/mL at 2 h after drug administration. CONCLUSIONS: Repeated oral administration of doxycycline in the horse resulted in steady state serum concentrations of < 1 microg/mL; however, it did not result in appreciable concentrations of drug in the aqueous and vitreous in normal eyes.     

Oesophageal strictures in cats associated with doxycycline therapy

Four cases of oesophageal stricture subsequent to doxycycline administration are reported. All cases were young to middle age (median age 3 years; range 1-7 years), and either domestic shorthair or domestic longhair breed. In all cases the predominant clinical sign was regurgitation, which developed at variable times after doxycycline administration. In all cases the reason for doxycycline use was treatment or prophylaxis of suspected infections (Mycoplasma haemofelis, Chlamydophila felis or Bordetella bronchiseptica), and the duration of therapy was variable. In one case the stricture was definitively diagnosed at post mortem examination, in the three other cases, definitive diagnosis was by endoscopy. Balloon dilation was successful in the three cases that were treated. This is the largest case series, to date, of oesophageal disease in cats associated with doxycycline administration. Caution should be exercised when administering oral medication to cats, especially doxycycline, and should be accompanied either by a water or food swallow.     

Susceptibility of bacteria from feline and canine urinary tract infections to doxycycline and tetracycline concentrations attained in urine four hours after oral dosage

OBJECTIVES: To measure urinary concentrations of doxycycline in cats and dogs and tetracycline in dogs 4 h after conventional oral dosing and determine whether these antibiotics were present in sufficient concentrations to be effective against common feline and canine urinary tract pathogens as assessed in vitro by Epsilometer and disc diffusion antimicrobial susceptibility methods. DESIGN: A prospective study involving oral administration to clinically normal cats and dogs of doxycycline or tetracycline (dogs only) and culture of bacteria from dogs and cats with urinary tract infections to determine their susceptibility to both doxycycline and tetracycline in vitro. PROCEDURE: In the first study, nine cats and eight dogs were administered doxycycline monohydrate (5 mg/kg every 12 h) and a further eight dogs were administered tetracycline hydrochloride (20 mg/kg every 8 h) for 72 h. Blood was collected at 2 and 4 h, and urine at 4 h, after the last dose. The concentration of each agent in serum and urine was determined by modified agar diffusion. In the second study, 45 urine samples from cats and dogs with urinary tract infections were cultured. Every bacterial isolate was tested in vitro using both Epsilometer (doxycycline and tetracycline) and disc diffusion (doxycycline, tetracycline or amoxycillin-clavulanate) tests. RESULTS: Serum doxycycline concentrations in sera of cats and dogs at 2 h were 4.2 +/- 1.0 mg/mL and 3.4 +/- 1.1 mg/mL, respectively. The corresponding concentrations at 4 h were 3.5 +/- 0.7 mg/mL and 2.8 +/- 0.6 mg/mL. Urinary doxycycline concentrations at 4 h (53.8 +/- 24.4 mg/mL for cats and 52.4 +/- 24.1 mg/mL for dogs) were substantially higher than corresponding serum values. Serum tetracycline concentrations in dogs at 2 and 4 h, and in urine at 4 h, were 6.8 +/- 2.8, 5.4 +/- 0.8, 144.8 +/- 39.4 mg/mL, respectively. Most of the urinary tract pathogens (35/45) were susceptible to urinary concentrations of doxycycline and 38/45 were susceptible to tetracycline. In contrast 41/45 of all isolates were susceptible to amoxycillin-clavulanate. CONCLUSION: This is the first report of urinary concentrations of doxycycline after conventional oral administration. Concentrations attained in the urine of normal cats and dogs were sufficient to inhibit the growth of a significant number of urinary tract pathogens and thus doxycycline may be a useful antimicrobial agent for some urinary tract infections.