A comparison of surface and rectal temperatures between sheared and non-sheared alpacas (Lama pacos)

The objective of this research was to determine if whole-body shearing would effect gross thermoregulation in alpacas. Eight mature, intact male alpacas were randomly assigned to one of two groups and maintained in outdoor pastures with adequate artificial shade from June through August (summer climate) in east central Alabama, USA. Group one animals (N=4) were sheared to remove all fiber to within 2 cm of their skin. Group 2 animals (N=4) were left non-sheared. Sheared alpacas tended to have lower rectal temperatures during high ambient temperatures than did non-sheared alpacas (P=0.06). Thermographic studies of the scrotum revealed cooler surface temperatures in sheared versus non-sheared alpacas (P=0.05). Temperatures in the right medial thigh of sheared animals were 0.9°C cooler than the thigh region of non-sheared animals in the morning (P<0.03). Right medial thigh temperatures were 1.6°C cooler in sheared alpacas in the afternoon (P<0.01). Significant positive correlations were found in non-sheared animals between ambient temperature and rectal temperature in the morning (r=0.612, P=0.014). In sheared animals during the morning significant positive correlations were established between the Heat Stress Index (HSI) and the right medial thigh surface temperatures (r=0.648, P=0.003), the HSI and rectal temperature (r=0.729, P=0.0003), the ambient temperature and right medial thigh surface temperature (r=0.485, P=0.04), and the ambient temperature and the rectal temperature (r=0.823, P<0.0001). In the afternoon a significant positive correlation was found in the sheared alpacas between the HSI and the right medial thigh surface temperature, rectal temperature and surface scrotal temperature (r=0.538, P=0.02, r=0.543, P=0.019 and r=0.522, P=0.045), respectively. These data indicate that whole-body shearing of alpacas could have a beneficial effect on thermoregulation when used as a preventative measure against heat stress. Shearing may assist heat dissipation resulting in a cooler surface body temperature and rectal temperature in alpacas when challenged by the heat and humidity experienced in the summer months in the southeastern United States.     

High follicle density does not decrease sweat gland density in Huacaya alpacas

When exposed to high ambient temperatures, mammals lose heat evaporatively by either sweating from glands in the skin or by respiratory panting. Like other camelids, alpacas are thought to evaporate more water by sweating than panting, despite a thick fleece, unlike sheep which mostly pant in response to heat stress. Alpacas were brought to Australia to develop an alternative fibre industry to sheep wool. In Australia, alpacas can be exposed to ambient temperatures higher than in their native South America. As a young industry there is a great deal of variation in the quality and quantity of the fleece produced in the national flock. There is selection pressure towards animals with finer and denser fleeces. Because the fibre from secondary follicles is finer than that from primary follicles, selecting for finer fibres might alter the ratio of primary and secondary follicles. In turn the selection might alter sweat gland density because the sweat glands are associated with the primary follicle. Skin biopsy and fibre samples were obtained from the mid-section of 33 Huacaya alpacas and the skin sections were processed into horizontal sections at the sebaceous gland level. Total, primary, and secondary follicles and the number of sweat gland ducts were quantified. Fibre samples from each alpaca were further analysed for mean fibre diameter. The finer-fibred animals had a higher total follicle density (P<0.001) and more sweat glands (P<0.001) than the thicker-fibred animals. The fibre diameter and total follicle density were negatively correlated (R²=0.56, P<0.001). Given that the finer-fibred animals had higher follicle density and more sweat glands than animals with thicker fibres, we conclude that alpacas with high follicle density should not be limited for potential sweating ability.     

Reference values for biochemical parameters in blood serum of young and adult alpacas (Vicugna pacos)

The aim of this study was to establish reference interval for biochemical parameters in blood of alpacas on the basis of large population of clinically healthy animals, and to determine the influence of sex, age and season on nitrogen and lipid metabolites, enzymes, electrolytes, vitamins and minerals in blood of alpacas. Blood samples were collected from 311 alpacas (61 males and 201 females >6 months of age and 49 crias (21 males and 28 females) ⩽6 months of age). Selected farms were located in Central Europe (Czech Republic and Germany). We determined 24 biochemical parameters from blood serum. We performed the comparison of results by the sex of animals and for the older group also the comparison of the results with regard to the season, respectively, to the feeding period. We found no highly significant difference (P<0.01) between males and females with the exception of γ-glutamyl transferase (GGT), alkaline phosphatase (ALP) and cholesterol. We found 15 significantly different parameters between the group of crias 6 months of age and the older alpacas. Based on our findings we suggest for most parameters to use different reference intervals (especially ALP, cholesterol, total protein, globulin, non-esterified fatty acids (NEFA), GGT and phosphorus) for the two above-mentioned age groups. Another important finding is the differences between some parameters in older group of alpacas in summer/winter feeding period. Animals in the summer feeding period have higher values of parameters related to fat mobilization (β-hydroxybutyrate, NEFA) and liver metabolism (bilirubin, alanine aminotransferase). The winter period with increased feeding of supplements with higher amount of fat, vitamins and minerals is characteristic by increased values of cholesterol, triglycerides, vitamins A and E, and some minerals (K, Ca, Mg and Cl) in blood serum. Clinical laboratory diagnosis of metabolic disturbances may be improved with use of age-based reference values and with consideration of seasonal differences.     

肾脏肿瘤患者CT灌注参数与肾功能生化检测指标的相关性研究

目的:探讨肾脏肿瘤患者CT灌注参数与肾功能生化检测指标的相关性。方法:选取河北省第六人民医院2013年3月至2018年1月期间收治的35例肾脏肿瘤患者作为观察组,另选取同期来我院体检的35例健康者作为对照组,均对两组受试者实施CT灌注成像,获取等效血容量(Equiv BV)、表面渗透性(Ps)、血流量(BF)等CT灌注参数,并检测两组受试者血尿素氮(BUN)、血肌酐(Scr)、总胆固醇(TC)、甘油三酯(TG)等肾功能生化指标,对比两组受试者上述指标检测结果,采用Pearson相关分析CT灌注参数与肾功能生化指标的相关性。结果:与对照组相比,观察组CT灌注参数Equiv BV、Ps、BF均降低,肾功能生化指标BUN、Scr、TC、TG水平均升高,有统计学差异(P0.05)。Pearson相关分析结果显示,CT灌注参数Equiv BV、Ps、BF与肾功能生化指标TC、BUN均呈负相关(P0.05),与Scr、TG无相关性(P0.05)。结论:肾脏肿瘤患者的CT灌注参数Equiv BV、Ps、BF均较低,BUN、Scr、TC、TG水平均较高,且CT灌注参数与BUN、TC水平呈负相关性,可作为评估肾脏肿瘤患者肾功能的辅助方法。     

Effect of dietary iodine on thyroid hormones and energy blood metabolites in lactating goats

Aim of this work was to evaluate if long-term dietary supplementation of potassium iodide (KI) to dairy goats can influence metabolic and hormonal parameters. Thirty Sarda crossbred dairy goats were divided into three groups, which were orally administered 0 (control group; CON), 0.45 (low iodine group; LI) or 0.90 (high iodine group; HI) mg of KI/day, respectively. The daily dose of KI (76.5% of iodine) was administered as salt dissolved in water for 8 weeks. Plasma contents of nonesterified fatty acids (NEFA), urea, glucose, insulin, free triiodothyronine (FT₃) and thyroxine (FT₄) were determined weekly. Iodine supplementation increased significantly the FT₃ hormone (P = 0.007) and FT₃/FT₄ ratio (P = 0.001) and tended to influence the FT₄ hormone (P = 0.059). An iodine level × week of sampling interaction for NEFA (P = 0.013) evidenced a temporary concentration increase in supplemented groups. The ‘Revised Quantitative Insulin Sensitivity Check Index’ increased with KI supplementation (P ⩽ 0.01). Blood urea nitrogen (BUN) and insulin were lowered (P ⩽ 0.01) by iodine supplementation (groups LI and HI; P ⩽ 0.01). The glucose concentration evidenced an iodine level × week of sampling interaction (P = 0.025) due to an unexpected and temporary increase of its concentration in the CON group. Glucose concentration was decreased by KI supplementation only in LI group (P < 0.05). In conclusion, the daily supplementation of low doses of KI can improve insulin sensitivity and decrease BUN in dairy goats.     

缬沙坦胶囊联合醋酸泼尼松片治疗原发性肾病综合征患儿的疗效及对肾功能及炎性因子的影响

目的:探讨原发性肾病综合征(NS)患儿在醋酸泼尼松片治疗的基础上联合缬沙坦胶囊治疗的临床疗效及对肾功能和炎性因子的影响。方法:选取2017年2月~2019年4月期间我院收治的NS患儿107例,根据随机数字表法分为对照组(n=53,醋酸泼尼松片治疗)和研究组(n=54,对照组的基础上联合缬沙坦胶囊治疗),比较两组患儿的临床疗效、肾功能指标及炎性因子指标变化情况,记录两组治疗期间不良反应情况。结果:研究组治疗12周后的临床总有效率为90.74%(49/54),高于对照组的69.81%(37/53)(P<0.05)。两组患儿治疗12周后白蛋白(Alb)较治疗前升高,24 h尿蛋白定量、肌酐(Cr)、尿素氮(BUN)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、白介素-8(IL-8)均较治疗前降低(P<0.05);研究组治疗12周后Alb高于对照组,24 h尿蛋白定量、Cr、BUN、IL-6、IL-8、TNF-α则低于对照组(P<0.05)。两组不良反应发生率比较无差异(P>0.05)。结论:缬沙坦胶囊联合醋酸泼尼松片治疗在提高NS患儿疗效的同时还可有效改善患儿肾功能及炎性因子水平,用药安全性较好。     

远端缺血预处理对同种异体肾移植术后患者肾功能的影响

目的:探讨远端缺血预处理对同种异体肾移植术后患者肾功能的影响。方法:选择行同种异体肾移植手术的患者20例,并将其随机分为实验组(S)和对照组(D),每组10例。S组于麻醉后在左下肢绑扎止血带行远端缺血预处理,D组不作缺血预处理。分别于术前(T0)、术后24(T1)、48(T2)、72h(T3)记录患者的尿量;生化检测患者血清尿素氮(BUN)和肌酐(Scr)含量;ELISA检测患者肾损伤分子-1(Kim-1)的含量。结果:两组患者的一般情况比较无统计学差异(P0.05)。两组患者术后各时点的尿量均较术前显著增加,且S组术后各时点的尿量均明显多于D组增多(P0.05)。两组患者术后各时点的Scr、BUN含量均较术前下降,两组T1、T2时点的Scr、BUN含量比较差异无统计学意义(P0.05),但S组术后T3时点血清Scr、BUN水平均明显低于D组(P0.05)。两组患者术后尿液Kim-1水平均较术前明显下降,S组在T3时点的Kim-1水平显著低于D组(P0.05)。结论:远端缺血预处理可显著减轻移植肾缺血再灌注损伤,有利于同种异体肾移植患者术后肾功能的恢复。     

Comparison of weather service heat indices using a thermal model

The US and Canadian weather service heat indices were evaluated to determine if one is a better predictor of the risk of heat injury. Heat index values were compared to the rectal temperature predicted by a heat-balanced-based thermal model to determine if there was a statistically significant relation between the heat index values and predicted rectal temperature. R² values ranged between 0.96 and 0.99 for the conditions investigated. Equations that predicted rectal temperature from the heat indices are presented. Both indices are highly correlated with predicted rectal temperatures.     

Impact of drinking of saline water on hemato-biochemical parameters of Black Bengal goats in the selected areas of Bangladesh

Global climatic changes are contaminating ground and surface water sources around the world, resulting in increased salinity. Knowing the animals' typical physiological capability for salinity tolerance without compromising their health is a necessity. The research was undertaken to determine the impacts of drinking water salinity on hemato-biochemical parameters of Black Bengal goats. A total of 40 Black Bengal goats (20 male and 20 female), age ranging from 1 to 5 years, were randomly selected and divided into 2 groups. The animals of group 1 received higher saline water (12 ppt) and those in group 2 received lower saline water (1 ppt) as regular drinking water. Blood parameters of all selected goats were measured. Serum creatinine, uric acid, urea, potassium, sodium, and chloride were significantly higher (P< 0.05) in the animals of group 1 compared with group 2, although serum phosphorous was significantly lower (P < 0.05) in group 1 compared with group 2. There were no significant differences in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), glucose, magnesium, and calcium between the animals of group 1 and 2. AST and magnesium differed significantly (P < 0.05) between young and adult goats in group 1. Glucose and urea levels were slightly higher (P < 0.05) in young goats. In both groups, male goats had significantly higher (P < 0.05) serum potassium and urea levels than female goats. The results suggest that Black Bengal goats of the coastal areas have different salt tolerance capacities based on their age and sex, and adapt to higher salinity by changing kidney functions.     

Thermoregulation of alpacas bred in Italy

The present study monitored daily and seasonal variations of rectal temperature in response to different environmental temperatures in alpacas bred in the Italian Apennines at 300 m a.s.l. In each season, the rectal temperature of 33 clinically healthy alpacas was measured three times/day (morning, midday, afternoon). Ambient temperatures were also recorded. Rectal temperatures ranged from a minimum value of 35.1 to a maximum of 39.4°C, with a maximum daily thermal excursion (ΔT_rec) of 3.2°C. Temperatures increased throughout the day, with highly significant differences recorded in both young and adult animals between all the time bands (P < 0.001). These differences were particularly dramatic for adults in summer, when the mean rectal temperature in the morning was 36.3 ± 0.13°C, probably as a consequence of recent shearing. Significant ΔT_rec differences were recorded depending on the season in both young and adult animals (P < 0.001), with the highest ΔT_rec values recorded in summer (although the highest daily ambient excursion value was recorded in winter). In conclusion, similarly to alpacas bred in their natural environment, alpacas bred in Italy show a wide thermal neutrality zone, which is probably an adaptive response, that allows the animals to save energy. In the Italian Apennines, in order to prevent situations of hypothermia, with possible detrimental effects on alpacas’ health and welfare, shearing should be carried out only in warm seasons.     

Influence des conditions climatiques saisonnières sur quelques paramètres physiologiques dès boucs Créoles alimentés avec de l'ensilage de banane

Response of three groups of 12 male creole goats (weighing about 10 kg) to environmental variations was tested in Guadeloupe (French West Indies) respectively at three times in the year: end of humid season (October–November), dry season (February–March) and beginning of humid season (July–August). Voluntary free intake of banana silage (silage of mixed green banana, bagassa, wheat bran and urea complemented with molasse) was not significantly affected by climatic variations. Three physiological parameters: rectal temperature, respiratory frequency and cardiac frequency were measured. These parameters were correlated with heat production dependent factors such as metabolic body weight, body weight gain and voluntary free intake. Rectal temperature increased all through the day until sunset and then decreased during the night. Both minimal rectal temperature and daily increase of rectal temperature were correlated with ambient temperature. Cardiac frequency increased during feeding. Generally cardiac frequency seemed to be correlated with activity of animals and so with behavioural response to environmental variations. Respiratory frequency was the most sensitive index of goat response to climate. The daily increase of respiratory frequency was important at the end of the humid season but was not observed in dry season. This increase was dependent on ambient temperature increase but also on air humidity characteristics and air velocity. These points are discussed according to integration of those physiological parameters in thermoregulation.     

血清尿素氮、碱性磷酸酶与儿童营养不良的相关性分析

摘要 目的：探讨血清尿素氮（BUN）、碱性磷酸酶（AKP）与儿童营养不良的相关性。方法：选择2017年10月至2022年10月我院接诊的108例儿童,根据是否存在营养不良将受试儿分为营养不良组（38例）和营养良好组（70例）。检测血清BUN、AKP水平,分析BUN、AKP与受试儿身体组分的相关性。多因素Logistic回归分析影响儿童营养不良的因素,受试者工作特征曲线（ROC）分析BUN、AKP诊断儿童营养不良的价值。结果：营养不良组血清BUN、AKP水平,体脂百分含量（fat percentage,F%）、总体脂肪（TBF）、瘦体重（LBM）低于营养良好组（P＜0.05）。儿童血清BUN、AKP水平与F%、TBF、LBM呈正相关（P＜0.05）。消化不良是儿童营养不良的危险因素（P＜0.05）,出生体质量、BUN、AKP、LBM是儿童营养不良的保护因素（P＜0.05）。联合BUN和AKP诊断儿童营养不良的曲线下面积为0.879,高于单独BUN和AKP诊断（P＜0.05）。结论：营养不良儿童血清BUN、AKP水平降低,且与身体组分改变和营养不良风险增加有关,联合检测血清BUN和AKP水平有助于评估儿童营养不良风险。     

Curcumin alleviates acute kidney injury in a dry‐heat environment by reducing oxidative stress and inflammation in a rat model

Curcumin exhibits anti‐inflammatory and antioxidant activities. We investigated the protective effects of curcumin in a renal injury rat model under dry‐heat conditions. We divided Sprague‐Dawley rats into four groups: dry‐heat 0‐ (normal temperature control group), 50‐, 100‐, and 150‐minute groups. Each group was divided into five subgroups (n = 10): normal saline (NS), sodium carboxymethylcellulose (CMCNa), and curcumin pretreated low, medium, and high‐dose (50, 100, and 200 mg/kg, respectively) groups. Compared to the normal temperature group, serum creatinine, blood urea nitrogen, urinary kidney injury molecule‐1, and neutrophil gelatinase‐associated load changes in lipoprotein (NGAL) levels were significantly increased in the dry‐heat environment group (P < .05); inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) expression and malondialdehyde (MDA) and related inflammatory factor levels were increased in the kidney tissue. Superoxide dismutase (SOD) and catalase (CAT) levels were decreased. However, following all curcumin pretreatment, the serum levels of kidney injury indicators and NGAL were decreased in the urine compared to those in the NS and CMCNa groups (P < .05), whereas renal SOD and CAT activities were increased and MDA was decreased (P < .05). Renal tissues of the 150‐minute group showed obvious pathological changes. Compared to the NS group, pathological changes in the renal tissues of the 100‐ and 200‐mg/kg curcumin groups were significantly reduced. Furthermore, iNOS and COX‐2 expression and inflammatory factor levels were decreased after curcumin treatment. Curcumin exerted renoprotective effects that were likely mediated by its antioxidant and anti‐inflammatory effects in a dry‐heat environment rat model.     

Assessing heat tolerance through productive vs physiological indicators. Data from dairy sheep under on-farm conditions

The search for criteria that allow the quantification of the level of thermotolerance of an animal is a major challenge in animal production. Different criteria have been proposed to date, mainly the use of routine milk recording and weather information or the collection of physiological measures related with heat stress. This study aimed at quantifying the association between indicators of heat tolerance derived from productive and physiological traits. For this purpose, two physiological traits, rectal temperature (RT) and respiratory rate (RR), and nine productive traits (milk yield, fat, protein and lactose yields and contents, casein and urea contents) were measured from June to September of 2018 in three flocks of Manchega sheep. A total of 462 lactating ewes participated in the study. Air temperature (Ta), relative humidity (RH) and associated temperature and humidity index (THI) were recorded inside the barn and also obtained from the closest weather station from the national meteorological network, and used to produce several measurements of heat load on animals. Based on the results of fits for quadratic and cubic regressions on the alternative heat load measures, the cubic regression on Ta and THI obtained inside the barn at time of recording yielded the best fit for physiological and productive parameters. The use of weather information taken from the official weather station closest to the farm also produced similar estimates and could be considered as a good alternative when on-farm meteorological data are not available. Two-trait random regression models that involved individual intercept and slope of response to heat load were used to obtain correlations between basal levels and heat tolerance within and across traits. Estimated correlations showed that animals with smaller vs larger basal levels of RT and RR tend to be more vs less heat tolerant (correlations up to 0.46) and that slopes of increase for RR and RT under heat stress were highly correlated (0.82). Estimated correlations between tolerance criteria from production vs physiology were up to ?0.5 (between milk yield and RT), indicating that animals that show less increase in body temperature also tend to show a smaller decrease in production under heat stress. However, because of the non-unity correlation between the two types of indicators of heat tolerance, both sources of information, productive and physiological ought to be taken into account to ensure the long-term sustainability of selection programmes aiming at improving productive levels when heat stress is a concerning issue.     

硝苯地平与硫酸镁治疗妊娠高血压综合征的临床疗效及对患者血清肌 酐、HSP70 及尿微量白蛋白水平的影响

目的:探讨硝苯地平联合硫酸镁对妊娠高血压综合征患者血清肌酐、HSP70及尿微量白蛋白水平的影响。方法:选取近5年在我院接受治疗的妊娠高血压综合征患者60例,随机分为实验组和对照组,每组30例。对照组患者采用硫酸镁治疗,实验组患者采取硝苯地平联合硫酸镁治疗。观察并比较治疗前后两组患者血清肌酐(Scr)、血尿素氮(BUN)、血尿酸(UA)热休克蛋白70(HSP70)及24 h尿微量白蛋白水平以及收缩压及舒张压的变化。结果:与治疗前相比,两组患者Scr、BUN、UA、HSP70及24 h尿微量白蛋白水平和收缩压及舒张压均显著降低(P0.05);与对照组相比,实验组患者上述指标均明显降低(P0.05)。结论:硝苯地平联合硫酸镁能够降低妊娠高血压综合征患者血压,保护患者肾功能。     

Changes in selected serum biochemical and EKG values with age in cynomolgus macaques

Normal serum values for alkaline phosphatase were significantly higher in juvenile male cynomolgus monkeys compared to adults. Conversely, blood urea nitrogen (BUN) was significantly lower in juveniles than adults. A comparison of selected EKG parameters from each group revealed no significant differences; however, there was a trend towards mean left axis deviation in adult animals.     

Photoperiodic control of the time of parturition in alpacas (Lama pacos)

Twenty-three mature female alpacas in late gestation in October (spring group) and in January (summer group), were randomly allocated to two treatments. In each season, one group was placed indoors under natural light and the other group was placed in a treatment room which could be totally blacked out to external light and had artificial lights controlled by an automatic time switch. Lights in the treatment room were switched on at 12:00 h and switched off at 02:30 h. Video cameras were used to record the times of parturition. The mean time of parturition for alpaces in the treatment room (16:43 h ± 69 min) was 6 h 23 min later (P < 0.001) than the alpacas in the control room (10:20 h ± 67 min). The mean intervals from sunrise or lights-on to parturition and from sunset or lights-off to parturition were similar for both treatment groups, and there were no effects of treatments on gestation length. The mean interval from the start of the treatments to parturition was shorter (P < 0.001) in the spring group(18 ± 2 days) than in the summer group (36 ± 2 days). In conclusion, the results showed that the time of parturition in alpacas is under photoperiodic control.     

核医学肾动态显像和血清Cys C在评价肾积水患者肾功能中的临床应用

目的:探讨核医学肾动态显像和血清胱抑素C(Cys C)在评价肾积水患者肾功能中的临床应用。方法:选择2014年1月至2015年1月我院收治的肾积水患者70例,依据肾积水程度将患者分为轻度积水组(21例)、中度积水组(26例)、重度积水组(23例)三组,选择同期我院体检中心的健康成人20例作为对照组,所有研究对象分别通过肾动态显像和双血浆法测量肾小球率过滤(GFR),分别记为I-GFR和rGFR,采用酶联免疫吸附法和血生化分析仪分别检测血清Cys C和尿素氮(BUN)、血肌酐(SCr)。结果:各组各指标比较差异均有统计学意义(均P0.05),肾积水患者r-GFR、I-GFR显著低于对照组患者,Cys C、BUN、SCr均显著高于对照组患者,差异有统计学意义(均P0.05);不同程度患者r-GFR、Cys C和SCr差异有统计学意义(均P0.05),其中,重度积水组中度积水组轻度积水组,差异有统计学意义(均P0.05);重度积水组I-GFR和BUN均高于轻度积水组和中度积水组,差异有统计学意义(均P0.05);rGFR和I-GFR与肾积水程度呈负相关(r=-0.967、-0.754,P=0.000、0.000),Cys C、BUN和SCr与肾积水程度呈正相关(r=0.883、0.627、0.671,P=0.000、0.002、0.001)。结论:核医学肾动态显像在评价轻度肾积水患者肾功能时更敏感,而血清Cys C在区分中、重度肾积水患者时更加准确,上述两指标作为替代双血浆法的检测方法在临床上应该互为补充,方能使诊断更加准确。     

A primary Corynebacterium pseudotuberculosis low dose infection in alpacas (Lama pacos) protects against a lethal challenge exposure

Corynebacterium pseudotuberculosis is the agent of alpaca's lymphadenitis. The present study was to demonstrate the effect of a primary infection with low (1.1 × 10³), moderate (1 × 10⁴), and high (1.2 × 10⁵) doses of C. pseudotuberculosis against a significant higher challenge dose of 9 × 10⁸ CFU of C. pseudotuberculosis. Three groups of 4 healthy male alpacas were inoculated subcutaneously (SC) in the left flank behind the costal arch with the above doses of bacteria. A fourth group of 4 alpacas was sham inoculated with phosphate buffered saline as control. After 5 weeks all animals were challenged with a dose of 9 × 10⁸ CFU of C. pseudotuberculosis inoculated SC in the right flank. The alpacas were clinically inspected for local and regional abscesses, body temperature and behavior changes. The primary infected alpacas had a febrile response, and abscesses at the inoculation point and regional lymph nodes. However, after challenge, the primary infected animals showed no superficial lesions or febrile response. In contrast, the immune naïve alpacas from group D developed a severe disease characterized by fever, abscesses in regional lymphnodes, and in one alpaca a subcutaneous edema and sudden death 2 weeks after exposure. In addition, primary infected alpacas had a robust antibody response against C. pseudotuberculosis cell wall antigen with significant differences with respect the naïve challenged alpacas. At necropsy, the primary infected alpacas had abscesses only in the regional or internal renal-lymph nodes from the left or primary inoculation side of the body, with no lesions in the right challenged side. In contrast, the primary sham inoculated alpacas had abscesses in the regional and internal lymph nodes from the right challenged side. This work showed that a primary infection with at least 1.1 × 10³ viable C. pseudotuberculosis induces protection against a second high dose exposure to this bacterium. These results will be useful for further study of prevention methods to control lymphadenitis in alpacas.     

Diversity and abundance of the bacterial 16S rRNA gene sequences in forestomach of alpacas (Lama pacos) and sheep (Ovis aries)

Two bacterial 16S rRNA gene clone libraries were constructed from the forestomach of alpacas and sheep fed alfalfa. After the amplification using the universal 16S rRNA gene primers, equal quantities of PCR products from the same species were mixed and used to construct the two libraries. Sequence analysis showed that the 60 clones from alpacas were divided into 27 phylotypes with 25% clones affiliated with Eubacterium sp. F1. The 60 clones from sheep were divided into 21 phylotypes with 7 phylotypes affiliated with Prevotella ruminicola (40% clones). Clones closely related to Clostridium proteoclasticum, Eubacterium sp. F1, Clostridium cellobioparum, Mogibacterium neglectum, Eubacterium ventriosum, Clostridiaceae bacterium WN011, Clostridium coccoides, Clostridium orbiscindens, Eubacterium sp. F1, Cytophaga sp. Dex80-37, Treponema bryantii and Pelotomaculum sp. FP were only found in the forestomach of alpacas, and those to Anaerovorax odorimutans, Treponema zioleckii, Bifidobacterium indicum, Paludibacter propionicigenes, Paraprevotella clara, Eubacterium siraeum, Desulfotomaculum sp. CYP1, Clostridium bolteae, Clostridium termitidis and Clostridiaceae bacterium DJF_LS40 only in the rumen of sheep. Quantitative real-time PCR revealed that the forestomach of alpacas had significantly lower density of bacteria, with bacterial 16S rRNA gene copies (6.89 [Log10 (copies per gram of wet weight)]), than that of sheep (7.71, P < 0.01). The two clone libraries also appeared different in Shannon index (library from alpacas 3.30 and from sheep 3.04). Our results showed that there were apparent differences in the bacterial diversity and abundance in the forestomach between alpacas and sheep.