Application of the California mastitis test in intramammary Streptococcus agalactiae and Staphylococcus aureus infections of camels (Camelus dromedarius) in Kenya

A study was conducted on 207 lactating camels in six herds in Kenya to evaluate the California mastitis test (CMT) for the detection of intramammary infections (IMIs) caused by Streptococcus agalactiae and Staphylococcus aureus and to investigate the prevalence of both the pathogens in the camel udder. IMI with S. agalactiae was found in 12% of all camels sampled. IMI with S. aureus was present in 11% of all camels sampled. The herd-level prevalence of IMI varied between 0 and 50% for S. agalactiae and between 0 and 13% for S. aureus. Longitudinal observations over 10–12 months confirmed persistent infections for both pathogens. Observations in one herd suggested that camel pox was a contributing factor in spreading and exacerbating S. agalactiae udder infections.The CMT had quarter-level sensitivities of 77 and 68% for S. agalactiae and S. aureus in camels, respectively. The CMT specificities were 91% for both the pathogens.     

Molecular Characterization of Phenotypically CAMP‐Negative Streptococcus agalactiae Isolated from Bovine Mastitis

In the present study three phenotypically CAMP‐negative Streptococcus agalactiae, isolated from three cows with mastitis, were characterized by molecular analysis. An identification of the S. agalactiae was performed by conventional methods and by PCR amplification of species specific parts of the 16S rRNA gene and the 16S‐23S rDNA intergenic spacer region. In addition all three phenotypically CAMP‐negative isolates harboured a normal sized CAMP‐factor encoding cfb gene indicating a reduced expression of CAMP‐factor or a gene defect elsewhere along the pathway of expression. The clonal identity of the three isolates could be demonstrated by macrorestriction analysis of their chromosomal DNA.     

Milk protein profiles in response to Streptococcus agalactiae subclinical mastitis in dairy cows

The objective of this study was to investigate the milk protein profiles of normal milk and those of milk during the course of subclinical mastitis, caused by natural Streptococcus agalactiae infection. Two‐dimensional gel electrophoresis and liquid chromatography mass spectrometry were used to assess protein profiles and to identify the proteins. The results showed that S. agalactiae subclinical mastitis altered the protein profiles of milk. Following Mascot database matching, 11 and 12 protein types were identified in the milk collected from healthy and S. agalactiae subclinical mastitic udders, respectively. The distinct presence of the antibacterial protein cathelicidin‐1 was detected in infected milk samples, which in turn was highly correlated to the severity of subclinical mastitis as represented by the milk somatic cell count (r = 0.616), but not the bacterial count. The protein profile of milk reveals changes in the host response to S. agalactiae intramammary infection; cathelicidin‐1 could therefore serve as a biomarker for the detection of subclinical mastitis in dairy cows.     

Chorioptes bovis (Acarina: Psoroptidae) in some camelids from Dutch zoos

The feet of three two-humped camels (Camelus bactrianus), one lama (Lama glama) and four alpacas (Lama pacos) from zoos and a circus in the Netherlands were examined for the mange-mite Choroptes bovis. Mites were found on two of the camels, the lama, and three of the alpacas. On one camel and one alpaca small mange lesions on the feet were present. This is the first report of Chorioptes bovis and chorioptic mange in the two-humped camel.     

Relationship of prepartum plasma concentrations of estrone sulfate and estradiol-17β with the weight of the calf and placental parameters in Holstein–Friesian cows

The aim was to evaluate the relationship of prepartum plasma estrone sulfate (E₁S) and estradiol‐17β (E₂β) concentrations with the weight of the calf and the placental parameters. Holstein–Friesian cows (n = 33) inseminated artificially with Japanese Black beef bull semen at Hiroshima University Farm in Japan were used for the experiment. Blood samples were taken every day from day 270 of gestation until the day after calving. The plasma samples were analyzed for E₁S and E₂β by enzyme immunoassay. The calf birth weight was taken immediately after calving. Complete fetal membranes were collected from 19 cattle and the weights of the placental components and the number of cotyledons were recorded. All 33 cattle delivered singleton normal calves. The prepartum plasma E₁S concentration was found to correlate significantly (P < 0.01) with the calf birth weight (r = 0.83), total fetal membrane weight (r = 0.81), cotyledonary weight (r = 0.79) and inter‐cotyledonary membrane weight (r = 0.64), but it did not correlate significantly with the number of cotyledons, whereas prepartum plasma E₂β was not found to correlate significantly with the weight of either the calf or any of the placental components except the number of cotyledons. In conclusion, prepartum plasma E₁S, not plasma E₂β, was found to correlate significantly with the weight of the calf and the placental components.     

双峰驼髂内动脉的形态学观察

采用血管内灌注有色油画颜料的方法,解剖观察了双峰驼髂内动脉的分支及分布情况.髂内动脉是骨盆部动脉的主干,其分支有脐动脉、臀前动脉、闭孔动脉、臀后动脉和阴部内动脉.阴部内动脉的分支有阴道动脉、直肠中动脉、会阴腹侧动脉和阴蒂动脉.在双峰驼未见有会阴背侧动脉.还就双峰驼和其它家畜髂内动脉的解剖学特点进行了比较讨论.     

Immunohistochemical Detection of Mycoplasma agalactiae in Formalin‐Fixed,Paraffin‐Embedded Tissues from Naturally and Experimentally Infected Goats

Samples from the mammary tissue of 14 lactating goats (12 naturally infected and two experimentally infected) were examined for the presence of Mycoplasma agalactiae. A monoclonal antibody (5G12) was applied to formalin‐fixed, paraffin‐wax‐embedded sections and labelled by the avidin–biotin peroxidase complex (ABC) method. Histological examination of tissue sections revealed strong immunoreactivity in all animals included in the study. Mycoplasma agalactiae antigen was mainly detected in the cellular debris at the periphery of purulent exudates present within lactiferous sinuses, and lactiferous and interlobular ducts. In addition, M. agalactiae organisms appeared in the cytoplasm of the epithelium of ducts, and in infiltrating macrophages and neutrophils within the ducts, alveoli, interstitial tissue and regional lymph node sinuses. It is concluded that this monoclonal antibody‐based immunohistochemical technique is an efficient and specific method for the post‐mortem detection of M. agalactiae in cases of clinical mastitis as well as being a useful tool for the study of the route of infection and cellular types involved during mastitis caused by this organism.     

Hump attachment structure of the two-humped camel (Camelus bactrianus)

The hump attachment structure was morphologically examined in the two-humped camel (Camelus bactrianus). The cranial hump is fixed by the trapezius and rhomboid muscles in the thoracic region. The strong collagen sheet in the basement of the hump is attached to the segmented bellies of the trapezius muscle, and the thoracic rhomboid muscle and the nuchal-supraspinous ligament support the attachment function of the trapezius muscle. The basement sheet possesses the line structure of collagen fibers, which are fitted to the segmented bundles of the trapezius muscle, and we observed that the muscle cells of the trapezius muscle are intermingled with the collagen fibers around the attachment line structure. In contrast, the caudal hump is directly attached to the subcutaneous tissue in the superficial region of the lumbar longissimus and lumbar iliocostal muscles. These findings demonstrated that the caudal hump of the two-humped camel is consistent with the hump of the one-humped camel in the attachment structure.     

A real-time polymerase chain reaction assay for the detection of Mycoplasma agalactiae

AIM: To develop a real-time PCR for the detection of Mycoplasma agalactiae, using PCR primers targeting the ma-mp81 gene.

METHODS: A group of 15 M. agalactiae isolates, 21 other Mycoplasma spp. isolates and 21 other bacterial isolates was used in evaluation of the assay.

RESULTS: All M. agalactiae isolates were detected by the assay and none of the non-target isolates was amplified. The analytical detection limit of the assay was 10 fg of purified genomic DNA and 10⁴ cfu/ml milk inoculated with M. agalactiae. When applied to goat-milk samples collected from three herds free of M. agalactiae infection, the assay had a specificity of 100%.

CONCLUSIONS: The assay would be useful in a diagnostic laboratory, providing specific, sensitive and rapid detection of M. agalactiae.     

Anti‐microbial Susceptibility of Streptococcus spp. Isolated from Bovine Mastitis in Argentina

The in vitro susceptibility to penicillin G, erythromycin and clindamycin was determined by the disc diffusion test and by E‐test for a total of 47 streptococcal strains (three Streptococcus uberis, 36 Streptococcus agalactiae, eight Streptococcus dysgalactiae spp. dysgalactiae) isolated from bovine intramammary infections in Argentina. Moreover, resistance phenotypes of erythromycin‐resistant streptococcal isolates was characterized. MIC₉₀ of penicillin G, erythromycin and clindamycin for S. agalactiae were 0.75, 8.0 and 12.0 μg/ml respectively. Resistance to erythromycin and clindamycin was detected in 13 (27.6%) and 12 (25.5%) isolates respectively. No isolate was resistant to penicillin G. Resistance against macrolides, lincosamides and streptogramin B (MLS_B) represented by the constitutive MLS_B phenotype was present in 11 (23.4%) erythromycin‐resistant isolates and two isolates (4.3%) expressed the M phenotype. The inducible MLS_B phenotype was not identified. Results suggest that beta‐lactams are the first‐line antibiotics when treating streptococcal udder infections; however, the continuous monitoring of the antibiotic resistance is essential, as the emergence of resistant strains has become a growing concern on the therapy of bovine mastitis.     

Studies with Bovine Parainfluenza — 3 Virus in U.A.R. (Egypt)

A bovine strain of myxovirus parainfluenza-3 (MP3) virus, designated S virus, was isolated from lung tissue collected from cattle with respiratory illness in 1963. The virus agglutinates mammalian and avian erythrocytes, and is sensitive to ether, sodium desoxycholate and trypsin. It grows in primary calf kidney, buffalo kidney, dog kidney, camel kidney and MS cell cultures. The S virus forms well-defined plaques in buffalo and calf kidney cells on the 5th or 6th day after inoculation. Examination of cell cultures following inoculation with S virus revealed giant cell formation, and introcytoplasmic and intranuclear inclusions. At 37°C the virus titer dropped from 10^10.4 to 10^2.6 in 3 days. Virus was completely inactivated at 56°C within 15 minutes. Growth-curve studies in tissue culture monolayer cells revealed a latent period of 10 hours. The intracellular virus titer was slightly lower than that of extracellular virus. The isolate was identified as MP3 virus by serum neutralization and hemagglutination-inhibition tests. Antibodies (HI) to S virus were shown to be present in a significant proportion of Egyptian cattle. The epidemiological significance of MP3 (bovine strain) virus in U.A.R. is discussed.     

On the morphology of the liver in the two-humped camel (Camelus bactrianus)

The liver of a two-humped camel (Camelus bactrianus) was examined by means of gross anatomy and histology. The liver appeared characteristically as an enlarged triangle in visceral aspect, and showed the following lobation: the left lateral and medial lobes, the right lobe, the caudate lobe and the quadrate lobe. These findings were similar to those for the one-humped camel. Histologically, a distinct lobulation, a typical arrangement of the interlobular connective tissue, and the trias was confirmed.     

The effect of lemongrass oil and its major components on clinical isolate mastitis pathogens and their mechanisms of action on Staphylococcus aureus DMST 4745

The aims of this study were to investigate the antibacterial activity of lemongrass oil (LG) and its major components which were citral, geraniol and myrcene, against four strains of clinically isolated bovine mastitis pathogens, including Staphylococcus aureus, Streptococcus agalactiae, Bacillus cereus and Escherichia coli by the broth microdilution method, as well as their activity on S. aureus biofilm formation. Attempts to clarify their mechanisms of action by investigation of the effects on intracellular material leakage and morphological changes of S. aureus DMST 4745 were also made. The results demonstrate that S. agalactiae and B. cereus are more susceptible to LG, citral and geraniol than S. aureus and E. coli. Moreover, they also inhibit S. aureus biofilm formation and exhibit effective killing activities on preformed biofilms. The LG appears to have multiple targets in the bacterial cell, depending on concentration used as well as the amount of its components.     

Cheyletiella parasitivorax infestation of cats associated with skin lesions of man

Two dry-cow therapy products were evaluated in seven factory-supply dairy herds in the Waikato area. A product containing neomycin sulphate and the benzathine salt of penicillin (Neopen D.C. White; Smith-Biolab) was used in five herds, and one containing benzathine cloxacillin (Orbenin, Beecham) was used in two herds. Non-treated control cows were included in each herd. Both products were effective in eliminating intramammary infections with Staphylococcus aureus, Streptococcus uberis, and Streptococcus agalactiae. Efficacy of dry-cow therapy against S. aureus was 83.8% and 85.2% respectively. Spontaneous cure rate among controls was 30.8% for S. aureus during the dry period. Spontaneous cure rate for Str. uberis was 50%, while dry-cow therapy eliminated 100% and 77.8%, respectively, for the two products. Dry-cow therapy with either product eliminated more than 90% of Str. agalactiae infections while spontaneous cure rate was only 28.6%. These results further support the effectiveness of dry-cow therapy in reducing the level of subclinical mastitis in dairy herds by shortening the duration of intramammary infections.     

Spatiotemporal patterns,annual baseline and movement-related incidence of Streptococcus agalactiae infection in Danish dairy herds: 2000–2009

Several decades after the inception of the five-point plan for the control of contagious mastitis pathogens, Streptococcus agalactiae (S. agalactiae) persists as a fundamental threat to the dairy industry in many countries. A better understanding of the relative importance of within- and between-herd sources of new herd infections coupled with the spatiotemporal distribution of the infection, may aid in effective targeting of control efforts. Thus, the objectives of this study were: (1) to describe the spatiotemporal patterns of infection with S. agalactiae in the population of Danish dairy herds from 2000 to 2009 and (2) to estimate the annual herd-level baseline and movement-related incidence risks of S. agalactiae infection over the 10-year period.     

Prevalence and Antimicrobial Resistance Pattern of Salmonella Isolates from Apparently Healthy Slaughtered Cattle in Ethiopia

The prevalence and antimicrobial resistance pattern of Salmonella isolates was determined from apparently healthy slaughtered cattle at Debre Zeit (Ethiopia). A total of 323 cattle were examined for the presence of Salmonella in faeces, mesenteric lymph nodes, abdominal and diaphragmatic muscles. Salmonellae were cultured from 23 (7.1%) of the animals. Salmonellae were isolated from 2 (3.1%) and 3 (4.5%) of 65 pooled faecal and mesenteric lymph node samples, respectively. Nine (2.8%) abdominal muscle and 10 (3.1%) diaphragmatic muscle samples (n = 323 of each) were contaminated by Salmonella. About 60% of the serovars identified in the abdominal and diaphragmatic muscles were also detected from faeces and mesenteric lymph node samples. The five different serovars isolated were Salmonella mishmarhaemek (48%), S. typhimurium (20%), S. enteritidis (12%), S. guildford (12%) and S. dublin (48%). The antimicrobial resistance profiles of 25 of the Salmonella isolates with 17 antimicrobials showed that 52% (13/25) of them were resistant to three or more antimicrobials. Both strains of Salmonella (S. mishmarhaemek and S. typhimurium) showed multiple resistance to ampicillin, sulfamethoxazole and ticarcillin. This revised version was published online in July 2006 with corrections to the Cover Date.     

Risk factors associated with camel brucellosis in Jordan

During the period between February, 2004 and December, 2006, a cross-sectional study was performed to investigate some epidemiological aspects related to camel brucellosis in Jordan. Four hundred twelve camel sera from 37 herds were randomly collected and analyzed using Rose Bengal plate test and complement fixation test. A structured pre-tested questionnaire was administered to collect information on camel herd health and management. A multivariable logistic regression model was constructed to investigate risk factors associated with seropositivity to Brucella antigens. Moreover, the incidence of Brucella-specific abortion was investigated in 7 camel herds located in different locations in Southern Jordan. The true prevalence of Brucella-seropositive in camels was 12.1%. Thirteen (35.1%) herds had at least one positive camel. The seroprevalence of brucellosis in camels was significantly higher in the southern part of Jordan than that in central or northern Jordan. The multivariable logistic regression model on both individual and herd levels revealed large herds and contact with small ruminants as risk factors for Brucella seropositivity. On the other hand, using disinfectants was identified as a protective factor (OR = 0.8; 95% CI: 0.1, 0.9) only on the camel herd level. The incidence of Brucella-caused abortion was 1.9%. Brucella melitensis biotype 3 was isolated from 4 aborted camel fetuses.     

Effect of extracted galactoglucomannan oligosaccharides from pine wood (Pinus brutia) on Salmonella typhimurium colonisation,growth performance and intestinal morphology in broiler chicks

1. An in vitro and in vivo study was conducted to evaluate the fermentability of isolated galactoglucomannan oligosaccharides (GGMs) and the influence of their feeding on shedding and colonisation of Salmonella typhimurium, growth performance and intestinal morphology in broiler chicks.

2. The in vitro data demonstrated that three probiotic lactic acid bacteria namely Lactobacillus casei, L. plantarum and Enterococcus faecium were able to ferment the extracted oligosaccharides and other tested sugars on a basal de Man Rogosa Sharpe media free from carbohydrate.

3. For the in vivo experiment, 144 one-d-old male Ross 308 broiler chicks were divided into 6 experimental treatments (with 4 replicates) including two positive and negative controls which received a basal maize-soybean diet without any additives, supplementation of three levels of isolated GGMs (0.1%, 0.2% and 0.3%) and a commercial mannanoligosaccharide (MOS) at 0.2% to the basal diet. All birds except those in the negative control group were challenged orally with 1 × 10⁸ cfu of S. typhimurium at 3-d post-hatch.

4. The results revealed that challenge with S. typhimurium resulted in a significant reduction in body weight gain, feed intake, villus height, villus height to crypt depth ratio and villus surface area in all of infected chicks. Birds that were given GGMs or MOS showed better growth performance, increased villus height and villus surface area and decreased S. typhimurium colonisation than the positive control birds. GGM at 0.2% level was more effective than the other treatments in improving growth rate as well as gut health of broiler chicks.

     

Efficacy of Spray Administration of Formalin-Killed Streptococcus agalactiae in Hybrid Red Tilapia

Abstract

An initial evaluation of spray vaccination was carried out with 60 hybrid Red Tilapia Oreochromis spp., divided into three groups that consisted of 10 fish per group with duplicates. The formalin-killed cells (FKCs) of Streptococcus agalactiae were administered once to group 1 by spray and once daily for five consecutive days to group 2. Group 3 remained as the untreated control group and was sprayed with normal saline. A booster was given twice to all the groups, once at the second week and again at the fourth week after the first vaccination. After this initial evaluation, a challenge study was conducted with 40 tilapia divided into two groups that consisted of 10 fish per group with duplicates. Group 1 was vaccinated with FKCs of S. agalactiae by a single spray administration while group 2 remained as the untreated control group. A booster was given twice using the same protocol as in the initial evaluation. After 6 weeks, fish from one of the duplicate tanks from each of groups 1 and 2 were challenged with pathogenic S. agalactiae by intraperitoneal (IP) injection, while fish in another tank were challenged through immersion. Based on the observations, serum immunoglobulin M (IgM) levels were significantly higher (P < 0.05) in the challenged fish than in the either the preexposed fish or the control group 1 week after the initial exposure. However, no significant differences (P > 0.05) were noted between challenged groups 1 and 2. In addition, no significant differences (P > 0.05) were observed between the frequencies of exposure. The mucus IgM level, however, remained high after each booster until the end of the 8-week study period. Meanwhile, serum IgM levels decreased after the challenge. A higher percentage of survival was noted for fish challenged through immersion (80%) compared with IP injection (70%). These results suggested that single spray exposure was able to induce IgM, which gave moderate to high protection during the challenge study.

Received October 9, 2012; accepted February 22, 2013     

Performance of camels (Camelus dromedrius) kept by pastoralists with different degrees of experience in camel keeping in Borana, Southern Ethiopia

The aim of the present study was to investigate the performances of camels kept by pastoralists with different degrees of experience in camel production. The study was conducted on 60 selected camel herds twice a year; during wet and dry seasons of 2003 and 2004 in Borana, Southern Ethiopia. The average ages at first parturition and calving intervals of breeding females were 68.1 ± 0.5 and 25.5 ± 0.4 months (LSMean ± SE), respectively. Age at first parturition was significantly reduced by use of veterinary services, while variation was not observed among Borana, Guji, Gabra and Somali herds. Calving intervals were significantly shorter (P < 0.05) in Borana (24.8 ± 0.6) and Guji (24.5 ± 1.5) than Somali herds (27.0 ± 0.5). Calving intervals were also prolonged (P < 0.05) by fixing breeding time. Annual calving, abortion and calf mortality rates were similar for the four populations and averaged 37.3%, 9.3%, 20.3% in 2003, and 41.3%, 8.2%, 14.9% in 2004, respectively. The overall mortality rate was significantly higher (P < 0.05) in Borana (10.0 ± 2.1) than in Gabra herds (4.2 ± 0.8). However, mortality was not statistically different for use of veterinary services and other managemental practices. The study showed an increase in annual herd growth by 5.7% in 2003 and 11.6% in 2004 with similarity of herd dynamics between the two years. Daily milk yield differed significantly (P < 0.05) depending on veterinary services, watering frequency and the season (7.6 L during wet and 4.3 L during dry season). Similarly, milk yield was significantly higher (P < 0.01) in Somali herds than in Borana and Gabra herds. In conclusion, the study revealed that some production and reproduction performances in camel herds have showed significant variation with varying levels of herding experience and veterinary services. This may suggest performance in pastoral camels can be enhanced with learning more about and using traditional management practices as well as improving animal health service delivery.