In-vitro susceptibility and ex-vivo evaluation of macrocyclic lactone endectocides sub-lethal concentrations against Plasmodium vivax oocyst development in Anopheles arabiensis.

BACKGROUND: Asymptomatic malaria transmission has become a public health concern across malaria-endemic Africa including Ethiopia. Specifically, Plasmodium vivax is more efficient at transmitting earlier in the infection and at lower densities than Plasmodium falciparum. Consequently, a greater proportion of individuals infected with P. vivax can transmit without detectable gametocytaemia. Mass treatment of livestock with macrocyclic lactones (MLs), e.g., ivermectin and doramectin, was suggested as a complementary malaria vector tool because of their insecticidal effects. However, the effects of MLs on P. vivax in Anopheles arabiensis has not yet been fully explored. Hence, comparative in-vitro susceptibility and ex-vivo studies were conducted to evaluate the effects of ivermectin, doramectin and moxidectin sub-lethal concentrations on P. vivax oocyst development in An. arabiensis. METHODS: The 7-day sub-lethal concentrations of 25% (LC25) and 5% (LC5) were determined from in-vitro susceptibility tests on female An. arabiensis in Hemotek® membrane feeding assay. Next, an ex-vivo study was conducted using P. vivax gametocytes infected patient's blood spiked with the LC25 and LC5 of the MLs. At 7-days post-feeding, each mosquito was dissected under a dissection stereo microscope, stained with 0.5% (w/v) mercurochrome solution, and examined for the presence of P. vivax oocysts. Statistical analysis was based on a generalized mixed model with binomially distributed error terms. RESULTS: A 7-day lethal concentration of 25% (LC25, in ng/mL) of 7.1 (95% CI: [6.3;8.0]), 20.0 (95%CI:[17.8;22.5]) and 794.3 (95%CI:[716.4;1516.3]) were obtained for ivermectin, doramectin and moxidectin, respectively. Similarly, a lethal concentration of 5% (LC5, in ng/mL) of 0.6 (95% CI: [0.5;0.7]), 1.8 (95% CI:[1.6;2.0]) and 53.7 (95% CI:[ 48.4;102.5]) were obtained respectively for ivermectin, doramectin and moxidectin. The oocyst prevalence in treatment and control groups did not differ significantly (p > 0.05) from each other. Therefore, no direct effect of ML endectocides on P. vivax infection in An. arabiensis mosquitoes was observed at the sub-lethal concentration (LC25 and LC5). CONCLUSIONS: The effects of ivermectin and doramectin on malaria parasite is more likely via indirect effects, particularly by reducing the vectors lifespan and causing mortality before completing the parasite's sporogony cycle or reducing their vector capacity as it affects the locomotor activity of the mosquito.

Prevalence and serotype of poultry salmonellosis in Africa: a systematic review and meta-analysis.

RESEARCH HIGHLIGHTS: The pooled sample prevalence of poultry salmonellosis in Africa is high (14.4%).The highest PPE was recorded in meat and meat products.Salmonella serotypes of zoonotic importance were found in all sample types.Salmonella Enteritidis and Typhimurium are common serotypes spreading in Africa.

Effect of Ivermectin® on survivorship and fertility of Anopheles arabiensis in Ethiopia: an in vitro study.

BACKGROUND: Innovative vector control tools are needed to counteract insecticide resistance and residual malaria transmission. One of such innovative methods is an ivermectin (IVM) treatment to reduce vector survival. In this study, a laboratory experiment was conducted to investigate the effect of ivermectin on survivorship, fertility and egg hatchability rate of Anopheles arabiensis in Ethiopia. METHODS: An in vitro experiment was conducted using 3-5 days old An. arabiensis adults from a colony maintained at insectary of Tropical and Infectious Diseases Research Center, Jimma University (laboratory population) and Anopheles mosquitoes reared from larvae collected from natural mosquito breeding sites (wild population). The mosquitoes were allowed to feed on cattle blood treated with different doses of ivermectin (0 ng/ml, 5 ng/ml, 10 ng/ml, 20 ng/ml, 40 ng/ml and 80 ng/ml). During each feeding experiment, the mosquitoes were held in cages and blood-fed using a Hemotek feeder. Mortality and egg production were then recorded daily for up to 9 days. Time to death was analysed by a Cox frailty model with replicate as frailty term and source of mosquito (wild versus laboratory), treatment type (ivermectin vs control) and their interaction as categorical fixed effects. Kaplan Meier curves were plotted separately for wild and laboratory populations for a visual interpretation of mosquito survival as a function of treatment. RESULTS: Both mosquito source and treatment had a significant effect on survival (P < 0.001), but their interaction was not significant (P = 0.197). Compared to the controls, the death hazard of An. arabiensis that fed on ivermectin-treated blood was 2.3, 3.5, 6.5, 11.5 and 17.9 times that of the control for the 5 ng/ml, 10 ng/ml, 20 ng/ml, 40 ng/ml, and 80 ng/ml dose, respectively. With respect to the number of hatched larvae, hatched pupae and emerged adults per fed mosquitoes, a significant difference was found between the control and the 5 ng/ml dose group (P < 0.001). The number of hatched larvae and pupae, and emerged adults decreased further for the 10 ng/ml dose group and falls to zero for the higher doses. CONCLUSION: Treating cattle blood with ivermectin reduced mosquito survival, fertility, egg hatchability, larval development and adult emergence of An. arabiensis in all tested concentrations of ivermectin in both the wild and laboratory populations. Thus, ivermectin application in cattle could be used as a supplementary vector control method to tackle residual malaria transmission and ultimately achieve malaria elimination in Ethiopia.

Pharmacokinetics of macrocyclic lactone endectocides in indigenous Zebu cattle and their insecticidal efficacy on Anopheles arabiensis.

Outdoor biting, outdoor resting, and early evening biting of Anopheles arabiensis is a challenge in current malaria control and elimination efforts in Africa. Zooprophylaxis using livestock treated with macrocyclic lactones is a novel approach to control zoophilic vectors. Therefore, the present study aimed to investigate the pharmacokinetics and insecticidal efficacy of ivermectin (IVER), doramectin (DORA), and moxidectin (MOXI) subcutaneous (SC) formulations in treated calves. The study was conducted using indigenous (Bos indicus) calves treated with SC formulation at a dosage of 0.5, 0.2 or 0.05 mg/kg body weight (BW) IVER or DORA and 0.2 or 0.05 mg/kg BW MOXI. Direct skin feeding of mosquitoes and animal blood sampling were performed at 4, 8, 12, and 24 h and on days 2, 3, 5, 7, 10, 14, 21, 28, and 35 post treatment. The survival of fully fed A. arabiensis mosquitoes was monitored for 10 days. Plasma samples were analyzed using UHPLC-MS/MS. A. arabiensis mortality percentages in the 0.5 mg/kg BW DORA and IVER groups were 65.74% (95% CI: [54.98; 76.50]) and 64.53% (95% CI: [53.77; 75.29]), respectively, over 35 days post treatment. At the recommended dose (0.2 mg/kg BW), promising overall A. arabiensis mortality rates of 61.79% (95% CI: [51.55; 72.03]) and 61.78% (95% CI: [51.02; 72.54]) were observed for IVER and DORA, respectively. In contrast, A. arabiensis mortality in the MOXI group was 50.23% (95% CI: [39.87, 60.58]). At 0.2 mg/kg BW dose, area under the plasma concentration versus time curve (AUC0-inf) values for IVER, DORA, and MOXI were 382.53 ± 133.25, 395.41 ± 132.12, and 215.85 ± 63.09 ng day/mL, respectively. An extended elimination half-life (T1/2el) was recorded for DORA (4.28 ± 0.93 d), at 0.2 mg/kg BW dose level, compared to that for IVER (3.16 ± 1.47 d). The T1/2el of MOXI was 2.17 ± 0.44 day. A maximum plasma concentration (Cmax) was recorded earlier for MOXI (10 h) than for IVER (1.6 days) and longer for DORA (3.0 days). For DORA and IVER, significant differences were found in T1/2el (P<0.05), Cmax (P<0.01), and AUC0-inf (P<0.01) between the higher 0.5 mg/kg BW and the lower 0.05 mg/kg BW doses. The T1/2el and AUC0-inf of DORA and IVER in the present study were significantly (p < 0.05) correlated with the observed insecticidal efficacy against A. arabiensis mosquitoes at 0.2 mg/kg a dose. Therefore, treating cattle with IVER or DORA could complement the malaria vector control interventions, especially in Ethiopia, where the zoophilic malaria vector A. arabiensis majorly contribute for residual malaria transmission.

CT measures of osseous cervicothoracic intervertebral foramina are repeatable and associated with CT measures of adjacent articular processes in horses.

Narrowing of the equine cervicothoracic intervertebral foramina (IF) has the potential to cause forelimb lameness and/or neck pain although limited information is available on CT of the IF. The aims of this retrospective, analytical study were to describe a protocol for quantifying CT cervicothoracic IF size; evaluate the repeatability of IF size measures; test associations between IF size and adjacent articular process (AP) size, ventral extent, and anatomic location; and determine the proportion of IF with narrowing. Computed tomographic images were acquired in 20 Warmblood horses that presented with forelimb lameness and/or neck pain. All IF between C5 and T2 (n = 160) were evaluated. IF cross-sectional area (CSA), APCSA, and AP ventral extent were measured. The repeatability of IFCSA measurement was calculated. Possible associations between IFCSA and: APCSA, ventral extent, side, or location were assessed. IF narrowing was defined as more than 50% of reduction in IF height when compared with its widest part(s). The repeatability of IFCSA measurement was excellent. There was a significant association between IFCSA and: APCSA (P < 0.001; R2 = 0.859; slope = -0.106), ventral extent (P = 0.022; R2 = 0.161; slope = -0.0617), and location (P < 0.001; higher values between C7 and T2). The association between IFCSA and ventral extent was small. Narrowing was identified in 61 (38.1%) IF. Maximum degree of narrowing was most common at the cranial (26.3%) and middle (68.8%) third of the IF. Narrowing was not identified at T1-T2. In conclusion, CT cervicothoracic IF size can be measured with excellent repeatability, and associations were found between IF size and: AP size, ventral extent, and location.

Anopheles arabiensis hotspots along intermittent rivers drive malaria dynamics in semi-arid areas of Central Ethiopia.

BACKGROUND: Understanding malaria vector's population dynamics and their spatial distribution is important to define when and where the largest infection risks occur and implement appropriate control strategies. In this study, the seasonal spatio-temporal dynamics of the malaria vector population and transmission intensity along intermittent rivers in a semi-arid area of central Ethiopia were investigated. METHODS: Mosquitoes were collected monthly from five clusters, 2 close to a river and 3 away from a river, using pyrethrum spray catches from November 2014 to July 2016. Mosquito abundance was analysed by the mixed Poisson regression model. The human blood index and sporozoite rate was compared between seasons by a logistic regression model. RESULTS: A total of 2784 adult female Anopheles gambiae sensu lato (s.l.) were collected during the data collection period. All tested mosquitoes (n = 696) were identified as Anopheles arabiensis by polymerase chain reaction. The average daily household count was significantly higher (P = 0.037) in the clusters close to the river at 5.35 (95% CI 2.41-11.85) compared to the clusters away from the river at 0.033 (95% CI 0.02-0.05). Comparing the effect of vicinity of the river by season, a significant effect of closeness to the river was found during the dry season (P = 0.027) and transition from dry to wet season (P = 0.032). Overall, An. arabiensis had higher bovine blood index (62.8%) as compared to human blood index (23.8%), ovine blood index (9.2%) and canine blood index (0.1%). The overall sporozoite rate was 3.9% and 0% for clusters close to and away from the river, respectively. The overall Plasmodium falciparum and Plasmodium vivax entomologic inoculation rates for An. arabiensis in clusters close to the river were 0.8 and 2.2 infective bites per person/year, respectively. CONCLUSION: Mosquito abundance and malaria transmission intensity in clusters close to the river were higher which could be attributed to the riverine breeding sites. Thus, vector control interventions including targeted larval source management should be implemented to reduce the risk of malaria infection in the area.

Dermal immune responses against Psoroptes ovis in two cattle breeds and effects of anti-inflammatory dexamethasone treatment on the development of psoroptic mange.

Psoroptic mange is a common disease of livestock, caused by Psoroptes ovis. Compared to Holstein-Friesian (HF) cattle, the Belgian Blue (BB) cattle breed is highly susceptible to the infestation. However, the mechanism for this difference is still unclear. To determine the factors responsible for this breed susceptibility, the immune response to P. ovis was studied in experimentally infested BB and HF cattle, using clinical signs, histology, immunohistochemical profiling and gene expression analysis of skin biopsies. The mite numbers and lesion area of BB cattle were greater than in HF during the whole study period. Significant influxes of eosinophils in the epidermis and dermis were detected in comparison with the pre-infestation samples in both breeds, with significantly higher eosinophils in BB at 6 weeks post infestation (wpi). Mast cell numbers were unaffected at all stages of infestation in HF, but were significantly elevated relative to pre-infestation in BB cattle at 2 and 6 wpi. The more pronounced cutaneous eosinophilia and higher IL-4 levels at 6 wpi in BB cattle suggest that a Th2-type immune response is underlying the higher susceptibility of the BB breed. In naturally infested BB cattle, development of the psoroptic mange lesions and eosinophils and CD3+ T cell areas were severely depressed after anti-inflammatory treatment with dexamethasone. Together, these results suggest that a stronger Th2-type immune response to P. ovis causes the skin lesions in psoroptic mange in BB cattle and that local anti-inflammatory treatment could potentially be an alternative to control the pathology caused by this parasite.

Occurrence, Molecular Characteristics, and Antimicrobial Resistance of Escherichia coli O157 in Cattle, Beef, and Humans in Bishoftu Town, Central Ethiopia.

Escherichia coli O157 is a Shiga toxin-producing E. coli causing disease in humans. Cattle are the primary reservoir of the pathogen. Information regarding the contribution of cattle to diarrheal illnesses in humans through consumption of contaminated beef is scarce in Ethiopia. We collected samples from 240 cattle, 127 beef, and 216 diarrheic patients in Bishoftu town in Ethiopia to assess the occurrence and determine the virulence genes, genetic relatedness, and antimicrobial resistance of E. coli O157. E. coli O157 was detected in 7.1% of the rectal content samples from cattle in slaughterhouses, in 6.3% (n = 127) of the beef samples, and in 2.8% of the diarrheic patients' stool samples. All isolates were positive for eae gene, 24 (77%) of them were positive for stx2 gene (21 stx2c and 3 stx2a), whereas stx1 gene was not detected. Molecular typing grouped the isolates into eight pulsed-field gel electrophoresis pulsotypes with three pulsotypes containing isolates from all three sources, one pulsotype containing one isolate from human origin and one isolate from beef. The remaining four pulsotypes contained isolates unique either to beef or to humans. With the exception of 1 multidrug-resistant isolate from beef, which was resistant to 8 antimicrobial drugs, the remaining 30 isolates were susceptible to the 14 antimicrobials tested. In conclusion, the finding of genetically similar isolates in cattle, beef, and humans may indicate a potential transmission of E. coli O157 from cattle to humans through beef. However, more robust studies are required to confirm this epidemiological link.

Prevalence, Antimicrobial Resistance, and Molecular Characterization of Salmonella in Cattle, Beef, and Diarrheic Patients in Bishoftu, Ethiopia.

Within Ethiopia, there is a lack of information on the genetic relatedness of Salmonella from cattle, beef, and diarrheic patients and its potential transmission from cattle to humans through consumption of contaminated beef. The objective of this study was to assess the prevalence and determine the serotypes, genetic relatedness, and antimicrobial resistance of Salmonella in cattle in two local slaughterhouses, in beef at retail shops, and in diarrheic patients in the only hospital in Bishoftu, Ethiopia. Salmonella was detected in 2.5% (6/240) of cattle samples, in 8.7% (11/127) of beef samples, and in 2.3% (5/216) of the diarrheic patients. Four Salmonella serotypes: Salmonella Typhimurium, Salmonella Eastbourne, Salmonella Saintpaul, and Salmonella Cotham were identified. Salmonella Typhimurium and Salmonella Eastbourne were isolated from cattle and beef, whereas Salmonella Saintpaul and Salmonella Cotham were isolated only from diarrheic patients. Except for serotype Salmonella Saintpaul, all isolates were grouped into five pulsotypes, of which two pulsotypes contained isolates from cattle and beef. Isolates from humans represented unique pulsotypes. Among the 22 Salmonella isolates tested, 95.5% were resistant to at least 1 of the 14 antimicrobials tested. Three Salmonella isolates originating from cattle were multidrug resistant. One human isolate was susceptible to all antimicrobials tested. More specifically, resistance to ampicillin, sulfamethoxazole, tetracycline, tigecycline, and trimethoprim were observed. The most frequently observed resistance was to sulfamethoxazole (90.9%, 20/22) followed by trimethoprim (22.7%, 5/22). The study revealed considerable Salmonella contamination of beef at retail shops, antimicrobial resistance to commonly used antimicrobials, and shared genetically similar Salmonella serotypes between cattle and beef; the link with humans could not be established. Still, the findings of Salmonella in cattle and beef, the propensity of transfer of Salmonella from cattle to beef coupled with the common consumption of raw/undercooked beef are likely to pose public health risk in Ethiopia.

Rearing of Hyalomma marginatum (Acarina: Ixodidae) under laboratory conditions in Morocco.

Hyalomma marginatum Koch is one of the main tick vectors of human and animal tick-borne diseases. The objective of this study was to establish standard procedures for rearing H. marginatum under laboratory conditions. Such laboratory tick populations are required to study acaricide resistance of Hyalomma ticks. In our rearing program, larvae and nymphs were fed on New Zealand white rabbits, whereas adults were fed on sheep. Non-parasitic stages were held at 18 and 28 °C to study the effect of temperature on development and survival. In our experiments, H. marginatum ticks have maintained the characteristics of a two-host life cycle. The engorged larvae did not detach and moulted on the rabbit, after which the emerged nymphs continued to feed on the same animal. The life cycle duration of H. marginatum was influenced by temperature, with each non-parasitic stage-i.e., larva and nymph molting-developing faster at 28 than at 18 °C; preoviposition and oviposition periods were shorter at 28 than at 18 °C. At 18 °C, no eggs hatched. The whole cycle from the collection of an engorged field tick until the emergence of second-generation larvae took 189 days. One such tick on average results in 3500 eggs which over time, taking into account the losses at each developmental stage, develop into 1200 adult ticks. Rearing these ticks a second generation therefore could result in millions of larval ticks.

Development of a dissolution method for lumefantrine and artemether in immediate release fixed dose artemether/lumefantrine tablets.

BACKGROUND: Dissolution of artemether (ART) and lumefantrine (LUM) active pharmaceutical ingredients (APIs) in fixed dose combination (FDC) ART/LUM tablets is one of the critical quality attributes. Thus, the verification of the release profile of ART and LUM from FDC ART/LUM tablets using a robust and discriminatory dissolution method is crucial. Therefore, the aim of this study was to develop and validate an appropriate dissolution method for quality control of FDC ART/LUM tablets. METHODS: The dissolution medium was selected based on saturation solubility data and sink conditions. The effect of agitation speed, pH and surfactant concentration on the release of ART and LUM was evaluated by employing a two-level factorial experiment. The resulting final method was validated for linearity, precision, robustness and API stability. In addition, the discriminatory power of the method was evaluated using expired and unexpired FDC ART/LUM products. RESULTS: A suitable dissolution profile of FDC ART/LUM tablets was obtained in 900 ml HCl (0.025 N, pH 1.6) with 1%Myrj 52 using paddle method at 100 rpm and 37 °C. ART and LUM were analysed using a HPLC method with UV detection at wavelengths of 210 and 335 nm, respectively. The results from the stability study showed that ART and LUM were sufficiently stable in HCl (0.025 N, pH 1.6) with 1%Myrj 52 at 37 °C. The method was linear (r2 = 0.999) over the concentration range of 6.25-100 µg/ml. The results for precision were within the acceptance limit (%RSD < 2). The percent relative standard deviation (< 2%) and statistically non-significant (p > 0.05) difference in release of ART and LUM observed between deliberately changed dissolution method settings (pH = 1.6 ± 0.2 or agitation speed = 100 ± 2) and optimized dissolution conditions revealed the robustness of the dissolution method. The method was capable to discriminate among different FDC ART/LUM products with different quality. CONCLUSIONS: The developed dissolution method is robust and discriminatory. It can be used in the quality evaluation of FDC ART/LUM tablets.

Short communication: J-5 Escherichia coli vaccination does not influence severity of an Escherichia coli intramammary challenge in primiparous cows.

The objective of the present study was to evaluate the efficacy of a J-5 Escherichia coli vaccine in a mild to moderate inflammatory challenge model using primiparous dairy cows for inoculation only. We hypothesized a clinical difference between placebo and J-5 E. coli vaccinated animals with the mild to moderate inflammatory challenge model. In case the null hypothesis could not be confirmed, the alternate hypothesis was no clinical difference between both treatment groups. Therefore, 23 primiparous cows in mo 7 of pregnancy were randomly assigned to 1 of 2 treatment groups: J-5 E. coli vaccine (n = 12) or placebo (n = 11). Animals were vaccinated 3 times at 56 (±7) and 28 (±7) d before expected calving date and within 14 d postcalving (DIM 5 ± 3). All cows were challenged by infusion with E. coli P4:O32 into 2 left mammary quarters between 14 and 28 d postparturition, at least 10 d after the 3rd vaccination, immediately after the morning milking. Clinical observations and blood and milk samples were collected at several time points from 7 d pre-challenge until 13 d post-challenge. Primiparous cows responded mild to moderately to intramammary E. coli challenge with little clinical difference between treatment groups. Rectal temperature increased earlier in the vaccinated animals, which also eliminated bacteria faster during the early hours after intramammary E. coli challenge. At post-infusion hour 9, the bacterial population was significantly lower in the infected quarters of the vaccinated animals. Blood leukocyte number was only numerically higher in the vaccinated animals, in combination with a numerically higher percentage of late immature polymorphonuclear leukocytes (band cells) in circulation. Even in the nonvaccinated animals, the E. coli challenge in the primiparous cows elicited only a mild to moderate response. The absence of a pronounced clinical difference between vaccinated and nonvaccinated animals was therefore not surprising.

Acaricide resistance status and identification of resistance mutations in populations of the two-spotted spider mite Tetranychus urticae from Ethiopia.

The intensive use of pesticides is a common practice for the management of the two-spotted spider mite, Tetranychus urticae, in greenhouses and field farms of Ethiopia. However, incidence of resistance and possible resistance mechanisms in T. urticae populations from Ethiopia have not yet been studied. Here, we assessed the toxicity of various acaricides-bifenazate, abamectin, emamectin benzoate, profenofos, fenbutatin oxide, fenpyroximate, amitraz and chlorfenapyr-on T. urticae populations sampled from six flower greenhouse farms, three strawberry greenhouse farms, one field-grown vegetable farm and two wild populations. In parallel, all populations were screened for known target-site mutations. All tested populations were fully susceptible to bifenazate, abamectin, emamectin benzoate and profenofos, but resistant against fenbutatin oxide and fenpyroximate. Four populations showed considerable levels of resistance against amitraz and one population was resistant to chlorfenapyr. Several target-site mutations were identified in the tested populations, including G119S, A201S, T280A, G328A and F331W/C/Y in acetylcholinesterase and the F1538I and L1024V mutation in the voltage-gated sodium channel. The F1538I mutation was found in eight out of 12 populations, whereas the L1024V mutation was only found in two populations. The H92R mutation in the PSST subunit of complex I and the I1017F mutation in chitin synthase 1 was detected in half of the tested populations. The G326E and I321T mutations in the glutamate-gated chloride channel 3 were also detected, but more rarely, whereas mitochondrial cytochrome b mutations were not detected. The current study revealed multiple resistance patterns in Ethiopian T. urticae populations and together with the wide presence of target-site mutations, calls for the wise use of acaricides in the management of T. urticae in Ethiopia.

Quality of fixed dose artemether/lumefantrine products in Jimma Zone, Ethiopia.

BACKGROUND: Malaria caused by Plasmodium vivax and Plasmodium falciparum is among the major public health problems in most endemic areas of the world. Artemisinin-based combination therapy (ACT) has been recommended as a first-line treatment for uncomplicated Plasmodium falciparum malaria almost in all endemic regions. Since ineffectively regulated medicines in resource limited settings could favour infiltration of poor quality anti-malarial medicines into pharmaceutical supply chain and jeopardize a positive treatment outcome, regular monitoring of the quality of anti-malarial medicines is critical. Thus, the aim of this study was to assess the quality of fixed dose combination (FDC) artemether (ART)/lumefantrine (LUM) tablets available in Jimma zone, Ethiopia. METHODS: This study was conducted in Jimma zone, Ethiopia. A total of 74 samples of FDC ART/LUM (20 mg ART/120 mg LUM) tablets were collected from 27 public facilities. All samples were subjected to visual inspection and the relevant information was recorded. The samples were transported to Jimma University Laboratory of Drug Quality (JuLaDQ) and stored at ambient temperature (20 °C to 25 °C) until analysis. The Pharmacopoeial conform/non-conform methods and the risk-based Derringer's desirability function approach were employed to assess the pharmaceutical quality of the investigated products. RESULTS: The visual inspection results revealed that there were no signs of falsified in the investigated products. Identification test results of samples indicated that all samples contained the stated active pharmaceutical ingredients (APIs). The results of uniformity of mass indicated that all samples complied with International Pharmacopoeial specification limits. The assay results, expressed as percent label claim (%lc) of ART (89.8 to 108.8%, mean ± SD = 99.1 ± 3.9%) and LUM (90.0 to 111.9%, mean ± SD = 98.2 ± 3.8%) revealed that, all samples complied with International Pharmacopoeia acceptance specification limits (i.e. 90-110%lc), except one generic product (IPCA Laboratories Ltd., India) which contains excessive LUM (111.9 ± 1.7%lc). The risk priority number (RPN) results revealed that assay (RPN = 392) is relatively the most critical quality attribute followed by identity (RPN = 280) and mass uniformity (40). Quality evaluation based on psycho-physical Harrington's scale revealed that more than 96% of samples were within the acceptable ranges (D ≥ 0.7-1.0). CONCLUSIONS: Both Pharmacopoeial and risk-based desirability function approaches to quality evaluation applied to the investigated products revealed that above 96% FDC ART/LUM tablets circulating in public settings of Jimma zone are of good quality.

Histopathological lesions in reproductive organs, distal spinal cord and peripheral nerves of horses naturally infected with Trypanosoma equiperdum.

BACKGROUND: Dourine, a venereal transmitted trypanosomosis caused by Trypanosoma equiperdum, has different clinical signs related to the reproductive and nervous system. Pathologic tissue changes associated with the disease are poorly described. The present study describes the histopathological lesions in naturally T. equiperdum-infected horses in the chronical stage of dourine. RESULTS: Four chronically dourine diseased horses underwent a post-mortem examination. They were Woo test negative, but CATT/T. evansi positive, had a low packed cell volume (PCV) and exhibited obvious clinical signs of dourine. Post-mortem examination did not reveal gross lesions in the organs assumed to be responsible for the symptomatology. On histopathology, genital organs were affected, with mononuclear cell infiltration and erosions and degeneration of seminiferous tubules and perivascular lymphoplasmacytic cuffing in the uterus. In the nervous system, mononuclear cell infiltration was located in peripheral nerves, ganglia and in the spinal cord, leading to axonal degeneration. Real-time PCR using ITS primer revealed the presence of trypanosomes in these organs and conventional PCRs using maxicircle and RoTat1.2 primers further confirmed the involvement of T. equiperdum since the DNAs from the vagina, testicle, distal spinal cord, sciatic and obturator nerves found to be positive for maxicircle and negative for RoTat 1.2. CONCLUSIONS: The histopathological lesions in the spinal cord and peripheral nerves explain the incoordination of the hind legs in T. equiperdum-infected horses, whilst its presence in the genital tract exemplifies the venereal transmission.

Reduction of Trypanosoma equiperdum from equine semen by single layer centrifugation.

Trypanosoma equiperdum (T. equiperdum) causes dourine, a venereally transmitted infection in horses. Purification of semen by single layer centrifugation (SLC) has been proven to be successful in reducing venereally transmitted diseases when dealing with other pathogens. The objective of this study was to evaluate the purification of T. equiperdum spiked semen by SLC. Semen was spiked using cryopreserved T. equiperdum stabilates (Dodola strain isolate 943). In total, 6 concentrations, varying from 102 to >5 × 106 trypanosomes, were added to semen samples. Subsequently, SLC was performed following standard procedures. The presence of the parasite in the purified semen was checked by wet smear examination, ITS1 PCR and in vivo inoculation in mice. Before SLC, all spiked semen samples, except the negative controls, were positive on PCR analysis. After SLC, all the pellets were found to be negative for T. equiperdum on microscopic examinations. Examination of the pellet by PCR could also not detect any parasite-DNA in the SLC-pellet of semen spiked with the lower number of parasites (102 to104 trypanosomes). However, in the SLC pellets spiked with 104 - 5 × 104 trypanosomes, only 1 out of the 4 replicates was negative for parasite DNA. All groups spiked with >5 × 104 trypanosomes were found to be positive on PCR. All mice in the positive controls exhibited parasitaemia (5/5). Mice inoculated with SLC-purified semen that was spiked with lower than 5 × 104 trypanosomes, remained free of parasitaemia, similar to the negative controls. However inoculation with SLC-pellets from samples with a higher number of trypanosomes (>5 × 104 - 5 × 106 and > 5 × 106), induced parasitaemia in 2 out of 5 and 3 out of 5 mice, respectively. This study indicates that single layer centrifugation can be used to clear T. equiperdum infected semen but that the success is dependent on the number of parasites.

Methylation of selected CpG islands involved in the transcription of myeloperoxidase and superoxide dismutase 2 in neutrophils of periparturient and mid-lactation cows.

It is generally accepted that intracellular killing of microorganisms by production of reactive oxygen species (ROS) in the phagosome of the neutrophil is an important arm of innate defense. High-producing dairy cows are prone to periparturient metabolic and infectious diseases. Both myeloperoxidase (MPO) activity and ROS production decrease the day of parturition. Several studies have demonstrated changes in the expression of genes involved in, for example, metabolism and defense in the circulating neutrophil during peripartum. In this study, we wanted to further characterize the periparturient neutrophil in terms of its oxidative killing capacity by analyzing the oxidative burst at 3 levels. First, the ROS phenotype was evaluated using chemiluminescence. The cows (sampled within 24 h after parturition and at 135 d in milk) showed a significantly slower production of ROS at parturition. Both primiparous (n = 13) and multiparous (n = 12) cows were included in this study, but parity did not affect the kinetics of ROS production. Second, the expression of 11 genes involved in ROS production was measured in the same cows: cytochrome b-245 α and ß chain (CYBA, CYBB; coding for membrane-bound constituents of NADPH oxidase); neutrophil cytosolic factors 1, 2, and 4 (NCF1, NCF2, and NCF4); Rac family small GTPase 1 and 2 (RAC1 and RAC2; coding for regulatory proteins of NADPH oxidase); superoxide dismutase 2 (SOD2); catalase (CAT); myeloperoxidase (MPO; coding for enzymes involved in metabolizing downstream ROS); and spleen-associated tyrosine kinase (SYK; involved in signaling). During peripartum, a shift in expression in the oxidative killing pathway was observed, characterized by a downregulation of MPO and a simultaneous upregulation of the genes coding for NADPH oxidase. Third, as total DNA methylation is known to change during pregnancy, we investigated whether the observed differences were due to different methylation patterns. Promotor regions initiate transcription of particular genes; therefore, we analyzed the methylation status in annotated CpG islands of MPO and SOD2, 2 genes with a significant difference in expression between both lactation stages. The differences in methylation of these CpG islands were nonsignificant. High-throughput techniques may be necessary to obtain more detailed information on the total DNA methylation dynamics in bovine neutrophils and increase our understanding of how gene expression is controlled in neutrophils.

Alfaxalone total intravenous anaesthesia in dogs: pharmacokinetics, cardiovascular data and recovery characteristics.

OBJECTIVE: To evaluate the cardiovascular effects, pharmacokinetic (PK) data and recovery characteristics of an alfaxalone constant rate infusion (CRI) of different duration in dogs at manufacturer's recommended dose rate. STUDY DESIGN: Experimental, prospective, randomized, crossover study. ANIMALS: Six intact female Beagles. METHODS: Following an intravenous alfaxalone bolus (3 mg kg-1), anaesthesia was maintained using an alfaxalone CRI at 0.15 mg kg-1 minute-1 for 90 (short CRI) or 180 minutes (long CRI). Venous blood samples were collected to determine the PK profile. Cardiovascular variables and recovery characteristics were evaluated. Recovery was scored on a scale ranging from 0, excellent to 4, bad. A mixed-model statistical approach was used to compare the cardiovascular parameters (global α = 0.05). An analysis of variance was performed to compare PK parameters and recovery times between treatments. RESULTS: No significant difference was noted between protocols for any PK parameter. Volume of distribution at steady state (935.74 ± 170.25 versus 1119.15 ± 190.65 mL kg-1), elimination half-life (12 ± 2 versus 13 ± 3 minutes), clearance from the central compartment (26.02 ± 4.41 versus 27.74 ± 5.65 mL kg-1 minute-1) and intercompartmental clearance (8.47 ± 4.06 versus 12.58 ± 7.03 mL kg-1 minute-1) were comparable for short CRI and long CRI. Cardiovascular variables remained within physiological limits. Mechanical ventilation was necessary (short CRI: n = 1, long CRI: n = 4). The manufacturer's recommended dose rate resulted in a light plane of anaesthesia. No significant differences in recovery times and scores were observed between treatments. The quality of recovery was scored as very poor with both protocols. CONCLUSIONS AND CLINICAL RELEVANCE: PK data were similar between long and short infusions of alfaxalone at the manufacturer's recommended dose, with acceptable cardiovascular conditions. Nevertheless, both protocols resulted in a superficial plane of general anaesthesia with poor recovery characteristics.

Effect of premedication on dose requirement, cardiovascular effects and recovery quality of alfaxalone total intravenous anaesthesia in dogs.

OBJECTIVE: To investigate alfaxalone total intravenous anaesthesia (TIVA) following premedication with methadone combined with acepromazine (ACP) or dexmedetomidine in bitches undergoing ovariohysterectomy. STUDY DESIGN: Prospective, blinded, randomized, experimental study. ANIMALS: A group of 12 female Beagles. METHODS: Dogs were premedicated intravenously with methadone (0.2 mg kg-1) combined with ACP (20 µg kg-1, group AM) or dexmedetomidine (5 µg kg-1, group DM). Anaesthesia was induced with alfaxalone (2 mg kg-1). Anaesthetic maintenance was obtained with an alfaxalone variable rate infusion (VRI) started at 0.15 mg kg-1 minute-1 and adjusted every 5 minutes based on clinical assessment. Mechanical ventilation was initiated when necessary to maintain normocapnia. Anaesthetic monitoring included electrocardiogram, heart rate (HR), invasive diastolic (DAP), systolic (SAP) and mean arterial blood pressure, arterial haemoglobin oxygen saturation, respiratory variables and oesophageal temperature. Data were recorded every 5 minutes. A mixed model statistical approach was used to compare cardiovascular variables within and between groups (α = 0.05). A Wilcoxon rank-sum test was used to compare body temperature, VRI alfaxalone rate, administered rescue analgesia, sedation, induction, intubation, recovery scores and recovery times between treatments. RESULTS: Overall HR, SAP and DAP differed between groups (p = 0.001, 0.016, 0.019, respectively). The mean VRI dose rate of alfaxalone differed between groups DM [0.13 (0.11-0.14) mg kg-1 minute-1] and AM [0.18 (0.13-0.19) mg kg-1 minute-1; p = 0.030]. Rescue analgesia was administered more in group AM (p = 0.019). No significant difference in recovery times and scores was observed between protocols. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone TIVA following dexmedetomidine/methadone premedication produced a more stable plane of anaesthesia to perform ovariohysterectomy than ACP/methadone. A dose reduction of alfaxalone of 27.7% was obtained in group DM compared with group AM. Recovery quality and recovery times were comparable between both groups.

Experimental infection model for vibriosis in Dover sole (Solea solea) larvae as an aid in studying its pathogenesis and alternative treatments.

Severe economic losses due to diseases in marine larviculture may be linked to vibriosis. To better understand the pathogenesis of vibriosis and evaluate new ways to prevent and combat this important disease, there is a great need for reliable and reproducible experimental infection models. The present study aimed at developing a challenge model for vibriosis in Dover sole larvae and testing its applicability to study the effect of the probiotic treatment. For that purpose, larvae were challenged at 10 days post hatching with Vibrio anguillarum WT, V. anguillarum HI610 or V. harveyi WT. Following administration of V. anguillarum WT via immersion at 1 × 107 colony forming units/mL, a larval mortality of 50% was observed at 17 days post-inoculation. In a next step, the probiotic potential of 371 isolates retrieved from Dover sole was assessed by screening for their inhibitory effects against Vibrio spp. and absence of haemolytic activity. One remaining isolate (V. proteolyticus) and V. lentus, known for its protective characteristics in seabass larvae, were further tested in vivo by means of the pinpointed experimental infection model. Neither isolate provided via the water or feed proved to be protective for the Dover sole larvae against challenge with V. anguillarum WT. This developed challenge model constitutes a firm basis to expedite basic and applied research regarding the pathogenesis and treatment of vibriosis as well as for studying the impact of (a)biotic components on larval health.