Successful Treatment of Captive Common Marmosets (Callithrix jacchus) Infested with Common Cat Fleas (Ctenocephalides felis) by Using Topical Imidacloprid and Environmental Control Measures

Fleas are ectoparasites affecting many animal species but reports in captive nonhuman primates are rare and mainly concern pet monkeys. Moreover, to the authors' knowledge, a detailed report on marmosets is not known at present. This case describes the clinical signs, diagnosis, treatment and follow-up of a flea infestation by Ctenocephalides felis in a captive colony of common marmosets. Fleas, flea feces and skin lesions were identified on two animals during annual health screening. Subsequently, the entire colony was examined, and nearly half of the colony showed signs of infestation. Consequently, treatment was initiated for the entire colony and the environment. Animals received two topical administrations of imidacloprid (5 mg for animals <200 g and 10 mg for animals weighing >200 g) three weeks apart, and their enclosures were decontaminated using vaporizers containing permethrin, piperonyl butoxide, and pyriproxyfen. Subsequently, skin lesions were resolved and no evidence of fleas were noticed. No side effects of the treatment were observed. Stray cats were identified as the source of the infestation. Their access to the animal-related rooms was stopped. No reinfestation has been reported for 3 years. The topical application of imidacloprid appeared effective with no adverse events occurring, so may be appropriate for use in other non-human primates.

Cerebral Activity in Female Baboons (Papio anubis) During the Perception of Conspecific and Heterospecific Agonistic Vocalizations: a Functional Near Infrared Spectroscopy Study

The "voice areas" in the superior temporal cortex have been identified in both humans and non-human primates as selective to conspecific vocalizations only (i.e., expressed by members of our own species), suggesting its old evolutionary roots across the primate lineage. With respect to non-human primate species, it remains unclear whether the listening of vocal emotions from conspecifics leads to similar or different cerebral activations when compared to heterospecific calls (i.e., expressed by another primate species) triggered by the same emotion. Using a neuroimaging technique rarely employed in monkeys so far, functional Near Infrared Spectroscopy, the present study investigated in three lightly anesthetized female baboons (Papio anubis), temporal cortex activities during exposure to agonistic vocalizations from conspecifics and from other primates (chimpanzees-Pan troglodytes), and energy matched white noises in order to control for this low-level acoustic feature. Permutation test analyses on the extracted OxyHemoglobin signal revealed great inter-individual differences on how conspecific and heterospecific vocal stimuli were processed in baboon brains with a cortical response recorded either in the right or the left temporal cortex. No difference was found between emotional vocalizations and their energy-matched white noises. Despite the phylogenetic gap between Homo sapiens and African monkeys, modern humans and baboons both showed a highly heterogeneous brain process for the perception of vocal and emotional stimuli. The results of this study do not exclude that old evolutionary mechanisms for vocal emotional processing may be shared and inherited from our common ancestor.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s42761-022-00164-z.

Deslorelin acetate implant induces transient sterility and behavior changes in male olive baboon (Papio anubis): A case study

This case study evaluates the effects of a 4.7 mg deslorelin acetate implant on one male olive baboon (Papio anubis). Implantation induces transient azoospermia after which the subject was able to conceive again. Behavior was also impacted with a decrease in our proxies of aggressiveness and sexual arousal.

Myocardial Thermal Ablation with a Transesophageal High-Intensity Focused Ultrasound Probe: Experiments on Beating Heart Models

Described here is a study of transesophageal thermal ablation of isolated and perfused beating hearts and non-human primates. An endoscope integrating a transesophageal echocardiography probe and a high-intensity focused ultrasound transducer was built and tested on five Langendorff-isolated hearts and three 30-kg baboons. B-Mode ultrasound, passive elastography and magnetic resonance imaging were performed to monitor thermal lesions. In isolated hearts, continuous and gated sonication parameters were evaluated with acoustic intensities of 9-12 W/cm². Sonication parameters of gated exposures with 12 W/cm² acoustic intensity for 5 min consistently produced visible lesions in the ventricles of isolated hearts. In animals, left atria and ventricles were exposed to repeated continuous sonications (4-15 times for 16 s) at an acoustic intensity at the surface of the transducer of 9 W/cm². Clinical states of the baboons during and after the treatment were good. One suspected lesion in the left ventricle could be evidenced by elastography, but was not confirmed by magnetic resonance imaging. The transesophageal procedure therefore has the potential to create thermal lesions in beating hearts and its safety in clinical practice seems promising. However, further technical exploration of the energy deposition in the target would be necessary before the next pre-clinical experiments.

STLV-1 co-infection is correlated with an increased SFV proviral load in the peripheral blood of SFV/STLV-1 naturally infected non-human primates

Simian T-Leukemia Virus type 1 and Simian Foamy Virus infect non-human primates. While STLV-1, as HTLV-1, causes Adult T-cell Leukemia/lymphoma, SFV infection is asymptomatic. Both retroviruses can be transmitted from NHPs to humans through bites that allow contact between infected saliva and recipient blood. Because both viruses infect CD4+ T-cells, they might interfere with each other replication, and this might impact viral transmission. Impact of STLV-1 co-infection on SFV replication was analyzed in 18 SFV-positive/STLV-1-negative and 18 naturally SFV/STLV-1 co-infected Papio anubis. Even if 9 animals were found STLV-1-positive in saliva, STLV-1 PVL was much higher in the blood. SFV proviruses were detected in the saliva of all animals. Interestingly, SFV proviral load was much higher in the blood of STLV-1/SFV co-infected animals, compared to STLV-1-negative animals. Given that soluble Tax protein can enter uninfected cells, we tested its effect on foamy virus promoter and we show that Tax protein can transactivate the foamy LTR. This demonstrates that true STLV-1 co-infection or Tax only has an impact on SFV replication and may influence the ability of the virus to be zoonotically transmitted as well as its ability to promote hematological abnormalities.

Foamy viruses infect a lot of mammalian hosts including non-human primates (NHP) and humans. Foamy infection is not associated with disease, although a recent report described hematological abnormalities in infected humans. Some NHP species are also naturally infected with another retrovirus i.e. Simian T lymphotropic virus type 1, while humans are infected with the Human T lymphotropic virus type 1 counterpart. Both viruses cause leukemia. Here we report that natural foamy/STLV-1 co-infection is associated with a higher foamy virus proviral load in blood. Co-infected animals might therefore present a higher risk of developing hematological disease.

Feasibility and reproducibility of ShearWave(TM) elastography of fetal baboon organs

OBJECTIVES

The purpose of this study was to assess the feasibility and reproducibility of transabdominal ShearWave(TM) elastography of fetal organs in pregnant baboons.

MATERIALS AND METHODS

Fetal ultrasounds of all pregnant baboons in a single primate research center were performed prospectively during 9 months. The visualization of fetal targeted organs (liver, proximal and distal lungs, brain white matter and periventricular gray matter) was initially performed using 2D ultrasound, and then elastography mode was activated. For each organ, three measurements were carried out by two operators. Intra-observer and inter-observer intra-class correlation coefficients (ICC) were calculated.

RESULTS

During the study period (03/2013-12/2013), 21 pregnant baboons (21 fetuses) were included. One to three ultrasound scans were performed for each fetus. The measurements were feasible by the two operators in all cases. The intra-observer and inter-observer ICC were 0.654, 95% CI (0.606 to 0.699) and 0.645, 95% CI (0.553 to 0.721) respectively.

CONCLUSION

Transabdominal ShearWave(TM) Elastography of fetal organs can be achieved in pregnant baboons. The intra-observer and inter-observer reproducibility is correct but vary according to the targeted organs.

[Functional studies of T and B lymphocytes]

The means for analysing T-cell activities are very limited. Indeed, the numerical estimation of the changes which take place in human T lymphocytes had to rely solely on the observation of transformed cells (blasts). However, even if various mitogens appear selective for either T of B cells, we know that both types of lymphocytes are ultimately transformed into blasts. This is particularly true in studies conducted on mixtures of T and B cells where stimulated T cells can release substances which act on B cells. On the other hand, studies with purified populations of T or B cells do not express the cellular interactions that occur naturally between these two types of lymphocytes. For all these reasons, it seemed that the estimation of " quanta " of activity unique to T lymphocytes would contribute significantly to our knowledge of this line of cells. We describe a new method of detecting the in vitro stimulation of lymphocytes based on the appearance of cells having the property to cluster several layers of sheep red blood cells (SRBC) around themselves, forming multilayer rosettes (CFC). This formation is temperature-dependent and requires trypanblue-excluding, metabolically active blastoid cells. Non-separated cells as well as purified T cells stimulated with allogeneic leucocytes (MLR), specific antigens or polyclonal mitogens (PWM, ConA) gave rise to CFC. Such multilayer rosettes were not formed by separated B cells. In the MLR, CFC were detected 48 h after beginning of cultures and increased in number thereafter just like thymidine incorporation. The response to ConA and PWM was detected earlier and gave rise to two or three peaks, the first rise in the number of CFC coinciding with the peak of thymidine incorporation, but the maximal increase occurring two or three days later. Treatment of blastoid cells with a serum specific for T cells--but not with an anti-immunoglobulin serum--abolished their ability to form ordinary or multilayer rosettes. When separated, however, on a nylon wool column, CFC were more adherent than the bulk of T cells. It is suggested that CFC form a subpopulation of T cells with distinct characteristics, allowing a direct assessment of membrane changes which take place when T lymphocytes are activated in vitro.