Sensitivity and Specificity of the Indirect Fluorescent Antibody Test in the Study of Four Murine Coccidia1

The sensitivity and specificity of the indirect fluorescent antibody (IFA) test for the detection of serum antibodies were examined in mice that were infected with Eimeria falciformis, E. ferrisi, E. papillata, or E. vermiformis. For the study of each species, five groups of mice were given graded inoculation doses of 10, 10², 10³, 10⁴, or 10⁵ sporulated oocysts in a primary infection. The sixth group was infected with three sequential doses of 1.5 times 10³, 1.5 times 10⁴, and 1.5 times 10⁵ sporulated oocysts per mouse at two- to three-week intervals. All groups of infected mice developed serum antibodies. Sera were titrated by the IFA test with purified sporozoites. Strong fluorescence and high IFA titers were observed with homologous reactions mainly with the sera from mice infected with the higher inoculation dose levels in primary infections and from those given three sequential inoculation doses. Immunological cross reaction among the four species of Eimeria occurred at dilutions of 1:10 to 1:160. Very weak or no fluorescence of free sporozoites was observed with sera from noninfected mice, and there was no fluorescence of sporozoites contained in intact sporocysts.     

Life cycle,growth characteristics and host cell response of <Emphasis Type="Italic">Rickettsia helvetica</Emphasis> in a Vero cell line

Rickettsia helvetica, a spotted fever rickettsia and emerging pathogen with Ixodes ricinus ticks as the main vector, is an agent of human disease and may cause febrile illness as well as meningitis. In three parallel series the isolated standard type of R. helvetica, obtained from a PCR-positive I. ricinus tick, was high-passaged and propagated in a Vero cell line. By using quantitative real-time PCR, the generation time from inoculation to stationary phase of growth was calculated to 20–22 h. In the static cultivation system the stationary phase was observed from the seventh day after inoculation, and there was no observed degradation of R. helvetica DNA during the 14 days studied. Microscopy showed that the organisms invaded the host cells rapidly and were primarily found free in the cytoplasm and only occasionally located in the nucleus. Four days after inoculation some of the host cells were broken and many indifferent stages of cytoplasmic organic decomposition were seen. However the R. helvetica organism did not show any morphologic alterations and the number of organisms was stable after the replication peak which may indicate that R. helvetica is adapted to growth in a Vero cell line and/or that the phase of degradation occurs later than the 14 days studied. The findings differ from what has been reported for other rickettsiae of the spotted fever group and may be of importance for invasiveness and virulence of R. helvetica.     

Life Cycle and Host Specificity of Eimeria larimerensis Vetterling, 1964, from the Uinta Ground Squirrel Spermophilus armatus1

SYNOPSIS. Eimeria larimerensis was found in 5 species of ground squirrels and the white-tailed prairie dog. The hosts included Spermophilus armatus from Utah and Montana, S. variegatus from Utah, S. tridecemlineatus from Wyoming, S. lateralis from Utah, S. beecheyi from California and Cynomys leucurus from Wyoming. Oocysts were not present in fecal samples of S. richardconi from Montana, S. lateralis from California or S. columbianus from Washington. This coccidium could not be experimentally transmitted to S. richardsoni; however, patent infections were established in S. armatus, S. lateralis, and S. variegatus. No infections were found after inoculation of least chipmunks (Eutamius minimus), Mongolian gerbils (Meriones unguiculatus), or laboratory rats even tho excystation occurred in these animals. Resistance to infection did not develop during repeated experimental infections of S. armatus, S. lateralis, or S. variegatus. No outward signs of coccidiosis were seen in any of the experimentally infected animals. In experimentally infected S. armatus, the prepatent period was 5 days, and the patent period lasted 3–7 (mean 6.5) days. The endogenous stages were located in the epithelial cells of the jejunum and ileum. Mature 1st-generation schizonts, 1st seen 2.5 days after inoculation, contained 16–32 merozoites. Mature 2nd generation schizonts were present 3.5 days after inoculation and contained 22–46 merozoites of a larger size than those of the 1st generation. Gametocytes were 1st seen 3.5 days after inoculation and developing oocysts were present 4 days after inoculation. Macrogametes contained eosinophilic granules which coalesced to form the oocyst wall. Formation of the macrogametes took place around cytoplasmic masses within the microgametocytes.     

Effect of tetanus toxoid inoculation on mortality in the Cayo Santiago macaque population

Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys (Macaca mulatta) on Cayo Santiago. From 1977 to 1984 the mean (±1 SD) annual total mortality rate (excluding neonatal deaths within 48 h postpartum, abortions, and stillbirths) was 6.39% ± .94%, and the mean annual tetanus mortality rate was 1.33% ± .45%. Tetanus deaths accounted for 19.5% of the total mortality in the colony. In 1985, all monkeys on the island, except infants and six adult monkeys, were given primary inoculations of tetanus toxoid. The following year, boosters were administered, and yearlings received primary inoculations. One fatal case of tetanus and one recovery from mild disease occurred in uninoculated adult monkeys in 1985, but no additional cases have been observed since. For 1985–1986 the mean annual total mortality rate was 3.69% ± .05%, and the mean annual tetanus mortality rate was .08% ± .08%. Thus, during the 2 years after inoculation against tetanus, the mean annual total mortality rate and the mean annual tetanus mortality rate declined by 42.2% and 94.0%, respectively, when compared to the 8-year period (1977–1984) prior to inoculation. These differences were significant [(χ² = 12.48; P < .005), (χ² = 16.94; P < .005)]. The elimination of tetanus infections through mass inoculation of the Cayo Santiago colony is expected to have a profound impact on the demography of the population by increasing the rate of population growth, by decreasing the differential rates of increase of the component social groups, and by changing the age distribution of the population.     

Induction of Disease Resistance by Nɛ-Trimethyl-L-Lysine in Bean Plants Against Uromyces phaseoli

The endogenous primary amino acid derivative N-Trimethyl-L-lysine (TML) induces resistance in bean plants against the biotrophic fungi Uromyces phaseoli The effectiveness of protection depends on the interval between treatment and inoculation of the plants and on the dosage of applicated TML It acts as resistance inducer within two concentration ranges of 10³–10^-3 and 10³–10¹⁰ mol/l, respectively, if applied 6 or 8 days after inoculation     

A new experimental model of acute osteomyelitis due to methicillin-resistant Staphylococcus aureus in rabbit

Aims: To assess the impact of antibiotic therapy on severe osseous infections, animal models of chronic bacterial infections have been developed; however, these models suffer from many experimental limitations. The aim of this work was to develop a new model system in which high levels of bacteria are obtained within femoral bone marrow and bone tissue, and such infections are maintained for at least 14 days. Methods and Results: Experimental osteomyelitis was induced in 25 New Zealand white rabbits. A 10⁹ CFU ml^?1 suspension of methicillin‐resistant Staphylococcus aureus was injected into the knee after bone trepanation. On day 3, surgical debridement was performed to mimic a surgical procedure. Animals were euthanized 1, 2, 3, 9 and 14 days post‐inoculation to determine the bacterial counts in marrow and bone, and to evaluate the stability of the infection. Inoculated lesions also were assessed for changes in histological parameters on days 3 and 7 post‐inoculation. At days 1, 2, 3, 9 and 14 post‐inoculation, we observed 6·50 ± 0·64, 7·30 ± 0·49, 7·82 ± 0·19, 8·00 ± 1·48 and 8·99 ± 0·20 log10 CFU g^?1 in bone marrow and 8·40 ± 0·68, 7·65 ± 0·27, 7·58 ± 0·30, 8·88 ± 0·52 and 8·28 ± 0·39 log10 CFU g^?1 in bone tissue, respectively. No statistical differences in bacterial count were found between bone marrow and bone tissue at any time point. Conclusion: This new model of acute osteomyelitis was validated by histological and microbiological changes in the absence of sclerosing agents, and these changes remained stable for 14 days. Significance and Impact of the Study: These results describe a new experimental model of acute osteomyelitis and demonstrate its usefulness in assessing the activity of antibacterial agents in vivo soon after bone infection.     

Subcutaneous Growth of Staphylococcus aureus Concomitantly Inoculated with Ehrlich Ascites Tumor Cells

Intratumoral growth of Staphylococcus aureus Cowan I-derived AP332 was examined by subcutaneous inoculation of cocci in doses ranging from 18 to 1.8 × 10⁵ CFU with Ehrlich ascites tumor cells. Inoculation of 18 CFU AP332 resulted in staphylococcal growth in one of five mice, and the proportion of mice established intratumoral infection increased with the initial inocula. Six other strains of S. aureus also grew in the tumor tissue, and none of the three strains of coagulase-negative staphylococci grew at all. Ethanol-killed tumor cells did not promote staphylococcal growth as vigorously as the live tumor cells, especially when the initial inoculum of AP332 was smaller than 10⁴ CFU.     

Translocation and multiplication ofSpiroplasma citri in turnip (Brassica rapa)

Following inoculation of designated leaves of turnip plants withSpiroplasma citri byCirculifer tenellus, spiroplasmas were cultured first from roots (four days) and then from youngest leaves (eight days), but almost never from oldest leaves. In experiments using enzyme-linked immunosorbent assay to monitor changes in titer in turnip leaves during the course of plant infection,S. citri was detected seven days after inoculation and reached peak titers of 10¹⁰–10¹¹ colony-forming units/g 12–20 days after inoculation, declining thereafter. Spiroplasmas were detected 5–9 days before symptoms appeared.     

Effects of X-irradiation on the immune response of guinea pigs to Q fever vaccine

The immune response of guinea pigs to Q fever vaccine following 75 to 250 R (60 to 180 rads) of acute whole-body irradiations was investigated. Complement-fixing (CF) antibody titers and protection against febrile response to challenge with virulent Coxiella burnetii were studied. Exposures ranging from 75 to 250 R, 24 hours prior to inoculation, did not detectably alter the CF antibody response. Similar results were observed with 175 R delivered 48 or 72 hours before immunization. Protection against febrile response to challenge with 10(3) median fever doses of C. burnetii was seen in animals irradiated with 175 R, 24 or 72 hours before immunization. Significant protection was detectable at 14, 21, and 42 days after immunization in both irradiated and nonirradiated animals. Acute irradiation of the degree studied increases the mortality in normal animals infected 15 to 17 days later with virulent C. burnetii. The lethal effect could be prevented by use of Q fever vaccine.     

Hormonal response to restraint in rhesus monkeys

Abstract: The purpose of this study was to characterize the hormonal responses to a restraining system in four adult male rhesus monkeys (Macaca mulatta) in preparation for a spaceflight project. After the monkeys were accustomed to food and water (Phase I), blood-volume-regulating hormones were measured during three phases: 10 days in a metabolic cage (Phase II), 16 days sitting in a restrained position in a specially designed metabolism chair (Phase III) and 10 days in metabolic cage (Phase IV). An increase of active renin (30%) and vasopressin (25%) was observed at the end of Phase III. A decrease of atrial natriuretic peptide (ANP), urodilatin, and sodium excretion occurred during the first days of Phase III. Catecholamines were unchanged. A dramatic increase (tenfold) in urinary excretion of growth hormone occurred during all of Phase III and at the beginning of Phase IV. These findings are similar to those found in man during isolation inactivity and during confinement stress.     

Gene expression in Brassica campestris showing a hypersensitive response to the incompatible pathogen Xanthomonas campestris pv. vitians

Xanthomonas campestris pv. vitians, a pathogen of lettuce, elicits a hypersensitive response within 12 hours of inoculation into Brassica leaves, characterized by tissue collapse, loss of membrane integrity, vein blockage and melanin production. In contrast, the compatible pathogen, X. c. pv. campestris, has no visible effects on leaves for 48 hours, after which inoculated areas show chlorosis which eventually spreads, followed by rotting.mRNA was prepared from leaves inoculated with suspensions of both pathovars or with sterile medium up to 24 hours following inoculation. In vitro translation of total and poly A⁺ RNA in rabbit reticulocyte lysate in the presence of ³⁵S methionine followed by separation of the polypeptide products by 2D-PAGE, allowed comparison of the effects of these treatments on plant gene expression. Major changes in gene expression were observed as a consequence of the inoculation technique. In addition, after inoculation with X. c. vitians, up to fifteen additional major polypeptides appeared or greatly increased by four hours. Some of these had disappeared by nine hours and several more had appeared. No major polypeptides disappeared or decreased greatly in intensity following inoculation with X. c. vitians.     

Potato Protoplast-derived Callus Tissue Challenged with Erwinia carotovora subsp. carotovora: Survival,Growth and Identification of Resistant Callus Lines*

Abstract Potato (cv. Crystal) protoplast-derived callus tissue was evaluated for survival and growth when exposed to Erwinia carotovora subsp. carotovora (strain Ecc71). Calli were either directly exposed to the pathogen by inoculation or to metabolites produced by the pathogen via a bilayer medium. Individual calli were inoculated with 0.5 μl of bacterial suspensions at 10⁴, 10⁵, 10⁶, 10⁷, 10⁸ and 10⁹ cfu/ml. The bilayer consistedof 10 ml of callus proliferation medium supplemented with pectin (2 g/l) and contained bacteria at 10², 10³, 10⁴, 10⁵ and 10⁶ cfu/ml. This medium was overlaid with 10 ml of bacteria free callus induction medium. Mean callus diameter of the inoculated treatments increased for 24 h, then declined. Over 90% of the inoculated calli were killed within 5 days but some survived as long as 14 days. Calli grown on the bilayer medium containing 10⁶, 10⁵ and 10⁴ cfu/ml also decreased in size. Most were killed within 9 days but some survived 20 days. Calli exposed to 10³ and 10² cfu/ml experienced limited growth with 20% and 7%, respectively, surviving after 27 days. Reactions to the pathogen varied considerably within the callus populations and individual calli with extended survival were identified in both experiments.     

Resistance of the European catfish (Silurus glanis) to channel catfish virus

European catfish (Silurus glanis) fingerlings (2 to 4 g each) were tested for susceptibility to channel catfish virus (CCV). They had supported CCV replication at 2 days after intraperitoneal injection with 0.1 ml of saline containing 10⁵ TCID₅₀. Homogenized visceral organs (liver, kidney and spleen) contained 10⁴ TCID₅₀/0.1 ml at 2 days post inoculation (PI) but at 4 days the titer decreased to 10¹ TCID₅₀. Bathing European catfish in CCV yielded only one positive sample with à titer of 10^0.83 TCID₅₀ per 0.1 ml of tissue. No clinical signs of CCV developed and no virus related deaths occurred.     

Effectiveness of prostaglandin F2α in restoration of HMG-HCG induced ovulation in indomethacin-treated rhesus monkeys

Six mature female rhesus monkeys were treated with HMG-HCG in control cycles at doses adjusted to induce ovulation while avoiding superovulation. Occurrence of ovulation was determined by observation of fresh ovulation points at laparotomy 48 to 120 hours following HCG. In subsequent cycles animals were treated with indomethacin (treatment days 4 through 10) together with the established dose of HMG_HCG. In 8 cycles indomethacin 5 mg/kg was given i.m. once daily; in 9 cycles 10 mg/kg i.m. was administered in 2 divided doses. Following this, PGF_2^α (3 mg t.i.d. s.c.) was administered for 3 days together with indomethacin 10 mg/kg and HMG-HCG, beginning on the day prior to HCG. Determinations of progesterone were performed by RIA on treatment days 4, 7, 10, and 11. Eleven of the 13 control cycles were ovulatory. With indomethacin 5 mg/kg/day, 5 of 8 cycles were ovulatory but ovulation was delayed in 2 instances. Of 9 cycles using indomethacin 10 mg/kg/day only 1 was ovulatory. When PGF_2^α was administered in subsequent cycles along with indomethacin (10 mg/kg) and HMG-HCG, ovulation occurred in 13 of 19 cycles. These data suggest that local ovarian PGF_2^α may be essential in the mechanics of follicle rupture in gonadotropin-treated rhesus monkeys.     

Infection and Stroma Formation by Venturia inaequalis on Apple Leaves with Different Degrees of Susceptibility to Scab

Conidia of Venturia inaequalis germinated and formed appressoria on all leaves independently of age and origin within the first 15 hours after inoculation. On the youngest expanded leaves of the apple variety Golden Delicious 80% of the conidia developed stromata within the first 24 hours, sporulation occurred after 8 days. On the second leaf (counted from the top of the twig) stroma formation was slowed down compared to the first and sporulation occurred after 10 days only. On the third leaf the fungus rarely formed stromata and never sporulated. The fourth leaf already showed complete ontogenetic resistance. In the diploid variety Priscilla the gene Vf, which confers resistance against scab to apple leaves, was expressed as reduced stroma formation without sporulation, as in the case of ontogenetic resistance. In the triploid variety Sir Prize with the gene Vf, stroma formation was retarded and colonization and sporulation occurred later on the first leaf, similarly to the reaction of the second leaf of variety Golden Delicious.     

Autoregulation of soybean nodulation: Delayed inoculation increases nodule number

The influence of seedling age at the time of inoculation on the regulation of nodule number in soybean (Glycine max [L.] Merr.) was examined in cv. Williams 82 and its hypernodulating mutant NOD1-3. Nodulation was evaluated on plants grown in plastic growth pouches or in vermiculite in 50- or 500-ml glass containers in growth chamber studies. Seeds or seedlings were inoculated once with Bradyrhizobium japonicum strain USDA 110 (10^k cells seedling^?1) between 0 and 15 days after sowing at 3- or 5-day intervals and were grown for 21 days after inoculation. Nodule number plant^?1 was similar across inoculation times in plants grown in growth pouches, but was significantly greater when inoculation was delayed and plants were grown in vermiculite in 500-ml containers. Plant culture in vermiculite in 50- or 500-ml containers confirmed the suppressive effect of restricted space for root growth on nodulation. Inoculation with 10⁵ or 10⁹ USDA 110 cells revealed that nodulation was inhibited by a high inoculum dose. There was a large increase in nodule number plant^?1 when plants were transferred from a restricted rooting environment (growth pouch culture) to a nonrestricted rooting environment (2-1 hydroponic pots). Autoregulation was also examined in split-root assemblies of plants in 500-ml containers of vermiculite. Controls involved concurrent inoculation of both root halves at 0. 4 or 8 days after transplant. Treatments involved time-separated inoculations of root halves with the primary and secondary inoculations being separated by 4 days. Plants were harvested at 21 days after inoculation. Williams 82 exhibited autoregulation of nodule number on the root half receiving delayed inoculation, regardless of plant age at the time of primary inoculation. Total nodule number plant^?1 invariably increased with later inoculation times. In contrast. NOD1 - 3 exhibited little, if any, autoregulation of nodule number. It was concluded that although Williams 82 exhibits autoregulation of nodule number and NODI - 3 does not, there was no finite limit to nodule number in either line since any delay in inoculation resulted in formation of a greater nodule number on both lines if root growth was not restricted. Nodule number in Williams 82 and NODI - 3 appears to be a function of infection sites (root size) at the time of inoculation and of subsequent plant growth.     

The Life Cycle of Isospora felis Wenyon, 1923, a Coccidium of the Cat*

SYNOPSIS. A pure strain of Isospora felis derived from a single oocyst was used to study the endogenous cycle. One and a half to two-month-old laboratory-reared, coccidia-free kittens were used thruout the study. The endogenous stages occurred in the epithelial cells of the distal parts of the villi in the ileum and occasionally duodenum and jejunum. All stages lay above the host cell nucleus. There were 3 asexual generations. The 1st generation schizonts were 11–30 by 10–23 μ when mature and contained 16–17 banana-shaped merozoites 11–15 by 3–5 μ. They became mature in 96 or sometimes in 120 hours. The 1st generation merozoites entered new host cells, rounded up and formed 2nd generation schizonts. These formed within themselves 2–10 or more spindle-shaped bodies resembling 1st generation merozoites in shape and size. These were 2nd generation merozoites. They were uninucleate 120 hours after inoculation, but by 144 hours they became larger, multinucleate and some lost their elongate shape and became ovoid. They were then 3rd generation schizonts. They were 12–16 by 4–5 μ. Each formed up to 6 or more banana-shaped merozoites 6–8 by 1–2 μ. The 3rd generation schizonts and merozoites developed within the same host cell and parasitophorous vacuole as the 2nd generation schizonts and merozoites. Mature schizonts containing only 3rd generation merozoites appeared 144 hours after inoculation, were most abundant 168 hours after inoculation, and might be present as late as 216 hours after inoculation. They were 14–36 by 13–22 μ and contained 36 to more than 70 merozoites. The 3rd generation merozoites entered the sexual cycle. The mature microgametocytes were 24–72 by 18–32 μ and contained a central residuum and a large number of microgametes 5–7 by 0.8 μ with 2 posteriorly-directed flagella. The mature macrogametes were 16–22 by 8–13 μ. Gametogony occurred 144–216 hours after inoculation. The prepatent period was 168–192 hours and the patent period 10–11 days. Peak oocyst production occurred on the 6th day of the patent period.     

The scanning electron microscopic study of the infection and conidial development of Aspergillus tamarii Kita on its host, the silkworm, Bombyx mori Linn.

Development of Aspergillosis on the integument of the silkworm, Bombyx mori Linn., was examined by scanning electron microscopy. Aspergillosis is a fungal disease caused by an insect mycopathogen Aspergillus tamarii Kita, which infects the silkworms in countries where sericulture (the rearing of silkworms)is prevalent. The present study showed the course of infection and the conidial development of A. tamarii on the integument of B. mori. Five different strains (KA, NB₁₈, NB₄ D₂, NB₇ and PM) of B. mori were inoculated on their body surface with ca. 1 × 10⁶ conidia/ml. Among the five breeds tested, the conidial germination was greatest on the larval surface of KA breed, and least on PM. Most of the conidia germinated on the cuticle approximately 8–12 hours after inoculation, forming a suctorial appressorium within 24 hours. The hyphae reached the hemocoel, where they grew and multiplied extensively, forming a mycelial complex and causing death of the host larva in about 5–6 days. The death of the host was followed by growth of the fungus through mesodermal and epidermal tissues, leading to larval mummification about 6–7 days post-inoculation. Extensive aerial outgrowths of the fungus followed, mostly through the intersegmental regions of larvae. Abundant branched conidiophores developed, forming a confluent yellow brown mat over the entire host body 7 days after inoculation. Each conidiophore had an apical vesicle bearing numerous phialides from which conidia were developed in long chains.     

Development of Eimeria auburnensis in Cell Cultures

SYNOPSIS. Monolayer established cell line cultures of bovine kidney (Madin-Darby) and human intestine (Intestine 407), as well as embryonic bovine tracheal and embryonic spleen cell line cultures were inoculated with E. auburnensis sporozoites and observed for a maximum of 22 days. Mature 1st generation schizonts developed in the kidney, tracheal and spleen cells. In the intestine cells, trophozoites were seen in 3 of 4 experiments, but schizonts were not found. Sporozoites penetrated cells, beginning within a few minutes after inoculation. Penetration was usually accomplished within 10 seconds, and the body of the sporozoite underwent a slight constriction as it passed thru the host cell membrane. Some sporozoites left cells. Numerous intracellular sporozoites were observed in kidney, tracheal and spleen cultures. Crescent bodies were seen in the parasitophorous vacuole as early as 1 day after inoculation. At this time, the nuclei of most intracellular sporozoites had changed from vesicular to compact. Beginning 4 days after inoculation, enlarged sporozoites and parasites having a sporozoite shape, but with 2-5 nuclei, were frequently seen. These enlarged sporozoites and sporozoite-shaped schizonts evidently transformed into trophozoites and spheroidal schizonts by means of lateral outpocketings. Few trophozoites were seen. More immature schizonts developed in kidney cells than in the other cell types. The numbers of mature schizonts observed in kidney and tracheal cells were similar, but development occurred less consistently in the latter. Few immature and mature schizonts developed in spleen cells. Mature schizonts, first seen 9 days after inoculation, were considerably smaller than those reported from calves. Some motile merozoites were seen; evidently no development beyond these occurred. The nucleus and nucleolus of host cells were enlarged; this enlargement was not as pronounced as in infections in calves. Multiple host cell nuclei were frequently observed. Degenerative changes in the cultured cells and in the parasites usually occurred, beginning 9-17 days after inoculation; these were more pronounced in the spleen cells than in the others.     

Cercopithecine Herpesvirus 9 (Simian Varicella Virus) Infection after Total-Body Irradiation in a Rhesus Macaque (Macaca mulatta)

This case report describes a rhesus macaque (Macaca mulatta; male; age, 5 y; weight, 6.7 kg) with anorexia, dehydration, lethargy, ataxia, and generalized skin rashes that occurred 30 d after total-body irradiation at 6.5 Gy (⁶⁰Co γ-rays). Physical examination revealed pale mucus membranes, a capillary refill time of 4 s, heart rate of 180 bpm. and respirations at 50 breaths per minute. Diffuse multifocal maculopapulovesicular rashes were present on the body, including mucocutaneous junctions. The CBC analysis revealed a Hct of 48%, RBC count of 6.2 × 10⁶/µL, platelet count of 44 × 10³/µL, and WBC count of 25 × 10³/µL of WBC. The macaque was euthanized in light of a grave prognosis. Gross examination revealed white foci on the liver, multifocal generalized petechiation on serosal and mucosal surfaces of the gastrointestinal tract, hemorrhagic lymph nodes, and hemorrhagic fluid in the thoracic cavity. Microscopic examination revealed cutaneous vesicular lesions with intranuclear eosinophilic viral inclusions within the epithelial cells, consistent with herpesvirus. Immunohistochemistry was positive for herpesvirus. The serum sample was negative for antibodies against Macacine herpesvirus 1 and Cercopithecine herpesvirus 9 (simian varicella virus, SVV). Samples submitted for PCR-based identification of the etiologic agent confirmed the presence of SVV DNA. PCR analysis, immunohistochemistry, and histology confirmed that lesions were attributed to an active SVV infection in this macaque. This case illustrates the importance of screening for SVV in rhesus macaques, especially those used in studies that involve immunosuppressive procedures.Abbreviations: SVV, simian varicella virus; TBI, total-body irradiation