Mycobacterium tuberculosis infections in cynomolgus monkey transplant recipients and institution of a screening program for the prevention and control of tuberculosis

A Novel Pre-Clinical Modeling of Massive Hemorrhagic Shock in Non-Human Primate: A Safe and Reproducible Method (Macaca fascicularis)

BACKGROUND

Although non-human primates are the closest animals to humans to simulate physiological and metabolic responses, there is a paucity of primate hemorrhagic shock models that are standardized and reproducible. Herein, we describe a model that is a clinical replica of extreme class IV hemorrhagic shock with a step-by-step description of the procedure in cynomolgus macaque monkeys.

METHODS

The physiological changes that occurred during the process were evaluated using hemodynamic parameters, echocardiogram, and laboratory values. Five female monkeys were subjected to trauma laparotomy, followed by cannulation of the abdominal aorta to achieve graded hemorrhage. A central line was placed in the right internal jugular vein, which was subsequently used for laboratory sampling and volume resuscitation. The withdrawal of blood was ceased when a predefined cardiac endpoint with cardiac arrhythmia or bradycardia was reached. The animals were then immediately resuscitated with transfusion. The primary cardiac endpoint was consistently reached in all 5 animals during the fourth hemorrhage when more than 70% of the estimated total blood volume was lost.

RESULTS

No mortality occurred during the process. The blood pressure, cardiac output measured from an echocardiogram, and hemoglobin correlated well with increasing loss of circulating volume, whereas the pulse pressure variation did not. The echocardiogram was also a useful predictor for urgent volume replacement.

CONCLUSION

This model offers a safe and reproducible surgical hemorrhagic model in non-human primates and simulates clinical practice. This could provide a useful platform on which further studies can be carried out to address unanswered questions in trauma management.

Pathologic characteristics of infectious diseases in macaque monkeys used in biomedical and toxicologic studies

Nonhuman primates (NHPs), which have many advantages in scientific research and are often the only relevant animals to use in assessing the safety profiles and biological or pharmacological effects of drug candidates, including biologics. In scientific or developmental experiments, the immune systems of animals can be spontaneously compromised possibly due to background infection, experimental procedure-associated stress, poor physical condition, or intended or unintended mechanisms of action of test articles. Under these circumstances, background, incidental, or opportunistic infections can seriously can significantly complicate the interpretation of research results and findings and consequently affect experimental conclusions. Pathologists and toxicologists must understand the clinical manifestations and pathologic features of infectious diseases and the effects of these diseases on animal physiology and experimental results in addition to the spectrum of infectious diseases in healthy NHP colonies. This review provides an overview of the clinical and pathologic characteristics of common viral, bacterial, fungal, and parasitic infectious diseases in NHPs, especially macaque monkeys, as well as methods for definitive diagnosis of these diseases. Opportunistic infections that can occur in the laboratory setting have also been addressed in this review with examples of cases of infection disease manifestation that was observed or influenced during safety assessment studies or under experimental conditions.

An outbreak of tuberculosis in endangered northern pig-tailed macaques (Macaca leonina) and milu deer (Elaphurus davidianus) from a zoo in China

BACKGROUND

Tuberculosis (TB) is a zoonotic disease that affects humans and domesticated and wild animals. Animals in zoos are potentially an important source of TB for humans; however they are often neglected in routine disease surveillance programs. This investigation reports an outbreak of TB in milu deer and northern pig-tailed macaques in a zoo in Wuhan, China, which highlighted the need for improved prevention and control of TB in China.

METHODS

Between 24 November and 9 December 2020 two milu deer and a northern pig-tailed macaque that were displaying signs of wasting died. Post-mortem, histopathological diagnosis and acid fast staining were used for the dead animals. Multiple PCR for Mycobacterium tuberculosis complex (MTBC) was performed to identify the bacterial in both milu deer and northern pig-tailed macaque. The serum antibody iELISA for MTBC was then performed for all the surviving milu deer and northern pig-tailed macaques. Six seropositive milu deer and a seropositive northern pig-tailed macaque were subsequently euthanised and, along with two other dead milu deer, necropsied. DNA from these tissue samples was extracted and detected MTBC using PCR and Real-time PCR. Subsequently bacterial isolation was used to confirm the infection.

RESULTS

The lungs of the dead animals displayed gross and histological TB-like lesions and changes, and red staining bacilli were detected in smears of the lesions by microscopy after acid fast staining. Mycobacterium bovis (M. bovis) was detected in the two milu deer and Mycobacterium tuberculosis (M. tb) in the northern pig-tailed macaque using multiple PCR for MTBC. 35.3% surviving milu deer and 50% surviving northern pig-tailed macaques MTBC serologically positive. Six of the euthanised milu deer were also positive on a DNA test for M. bovis and the euthanised northern pig-tailed macaque was positive to M. tb.

CONCLUSIONS

This is the first report of tuberculosis in the endangered species, milu deer and northern pig-tailed macaques, in China, and warrants urgent attention by researchers and conservation authorities. These cases highlight the need for expanding surveillance for MTBC to zoos in China.