Ectoparasites and phoretic arthropods were recovered from three commensal rodent species, Rattus rattus, Rattus norvegicus and Mus musculus, collected from three villages near the city of Bilbeis in Sharqiya Governorate, Egypt. A total of 67,300 ectoparasites were collected, 20,643 from 242 R. rattus, 40,997 from 277 R. norvegicus, and 5,660 from 55 M. musculus. Ectoparasites included twenty-one species: fourteen mites, four fleas and three lice. Individuals of eight common ectoparasite species formed 92.7% of the total number collected. They included three mites, three fleas and one louse species on both rat hosts and one mite species recovered from the house mouse. The mites Radfordia ensifera, Trichoecius sp., Myobia musculi, Myocoptes musculinus, and Afrolistrophorus sp. are recorded for the first time from Egypt. The presence of Trichoecius sp. on R. norvegicus represents a new host-ectoparasite association.

A longitudinal entomological survey for sandflies was conducted from 1989 to 1991 at a focus of enzootic cutaneous leishmaniasis in Northeast Sinai, Egypt, within the border region monitored by multinational peacekeepers. Standardized sampling with CDC light traps, oiled paper “sticky traps”, and human landing collection was employed to determine monthly trends in species composition, density, sex ratio, and reproductive status of vector sandflies. Each collection method independently defined sandfly seasonality as the period May–November in 1990, and March–October in 1991. Plebotomus papatasi was the only anthropophagic species found and comprised more than 94% of the sandfly population. Two population peaks (May, July) were observed for this species in both survey years. Density of P. papatasi in underground bunkers was higher than outside but inflated by a greater proportion of male flies. During 1990, the proportion of gravid P. papatasi increased progressively during the 5 months period from May to September and averaged 29.5% and 29.7% for interior and exterior collections, respectively. Density of P. papatasi was greater during 1991, but proportions of gravid flies were significantly lower in each survey month and averaged 14.9% and 12.3% for interior and exterior collections, respectively. Seasonal rates of Leishmania-infected P. papatasi averaged 0.8% and 0.9% in 1989 and 1990, but fell to zero in 1991, suggesting an unstable focus of Leishmania major transmission. Proportions of gravid flies may be a valid indicator of the physiological age and epidemiologic importance of the vector sandfly population at this focus. The strong correlation of sticky trap indices to human-landing/biting rates shows that this is an accurate, inexpensive, and no-risk alternative to human bait collections.

The present study was carried out in 3 villages, namely Kafr Ayoub Soliman, Kafr Ibrahim El-Aidi, and El-Sa'adat, Sharqiya Governorate, Egypt. A total of 519 rats was collected from the 3 study sites: 46.6% Rattus rattus, and 53.4% Rattus norvegicus. A total of 20,643 ectoparasites was recovered from R. rattus: 33.3% mites, 33.8% fleas, and 32.9% lice. From R. norvegicus a total of 40,997 ectoparasites was recovered: 28.9% mites, 31% fleas, and 40.1% lice. Three common mite species were recovered from both rat hosts, i.e., Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three common flea species were also recovered from both rat hosts, i.e., Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis. Polyplax spinulosa was the only dominant louse species that infested both rat hosts. Rats did not show a definite breeding season, and the seasonal rat indices were generally low in different study sites. There were no significant differences between the prevalence of each of mites, fleas, and lice in both rat species. The total general indices of mites and fleas, on the other hand, was significantly higher in R. norvegicus. The general index of X. cheopis was high and ranged between 5.9 in R. rattus and 14.5 in R. norvegicus. Season-related changes were observed in the general index of each of L. segnis infesting both rat species and R. ensifera and O. bacoti infesting R. norvegicus. The prevalence and general indices of some ectoparasites showed differences related to the locality of their rat hosts. Seasonal changes in the general indices of some ectoparasites paralleled seasonal changes in the relative abundance of their rat hosts.

The present study was carried out in the Bilbeis area, Sharqiya Governorate, Egypt. A total of 127 male and 115 female black rats Rattus rattus and 124 male and 153 female Norway rats R. norvegicus was collected during the study period. A total of 20,643 and 40,997 ectoparasites was recovered from R. rattus and R. norvegicus, respectively. Three common mite species were recovered from both rat hosts: Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three common flea species were also recovered from both rat hosts: Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis. Polyplax spinulosa was the only louse species that infested both rat hosts. Rats that lived more than 12 mo formed about 24 and 14% of the populations of the black and Norway rats, respectively. The prevalences and general indices of many ectoparasites were significantly higher on males than on females of both rat hosts. Seasonal differences in prevalences and general indices of many ectoparasites were recorded between the 2 sexes of both rat species. Prevalences and general indices of most ectoparasites on both rat species showed a tendency to increase with increasing size and age of rat hosts. The type and degree of correlation between prevalences and general indices on the one hand and each of body size and age on the other hand differed among the species of ectoparasites.

Protein and nucleic acid levels from the ovaries of Hyalomma dromedarii Koch were determined during different stages of oogenesis. The concentrations of total protein, DNA, and RNA increased during oogenesis, reflecting the rapid developmental changes taking place in this tissue. Peak protein and DNA levels were reached in the fully fed females, whereas RNA level peaked slightly earlier. Ribosomal RNA (rRNA) was found to be composed of 27.0s, 17.0s, and 4.1s particles. The ratio of 27.0s to 17.0s varied within the developing ovary, yet the 27.0s/4.1s ratio remained constant. The nucleotides of total RNA and rRNA were determined, and the ratio of purine/pyrimidine equaled approximately 1 and remained unchanged during oogenesis.

Twenty-two egg vitellins of Argas (Argas) hermanni Audouin were used to make antisera for immunoelectrophoretic analysis of vitellogenins and vitellins in the hemolymph and ovaries, respectively. Thirteen fractions were derived from extraovarian vitellogenins, seven were endogenous vitellins produced in the ovaries, and two vitellins with relative mobilities (Mr) of 35.5 and 47.2 kiloDaltons (kD) existed only in the deposited eggs. Almost all exogenous vitellins and their hemolymph counterparts (vitellogenins) were hemoglycolipoproteins with a relatively low Mr of 66.2 to >200 kD. Endogenous vitellins exhibited a higher Mr of 22–59 kD and were of a more variable chemical nature. The hemolymph of the female had more protein fractions (22–24) than that of the male (15). All proteins in the male had corresponding fractions in the female hemolymph with similar electrophoretic mobilities and five fractions were immunologically identical common vitellogenins. Eight female-specific vitellogenins were restricted to the female hemolymph, and two of them with high Mr of 14.4 and 16.5 kD appeared at the onset of oviposition. Ovaries contained 28 protein fractions that exhibited great fluctuations in their number and concentration during the different physiological states examined. Five to 13 fractions were exogenous vitellins; 6 appeared during vitellogenesis and the onset of oviposition. One to seven endogenous vitellins were detected in the ovaries primarily during the period just before the initiation of vitellogenesis. The significance of these results is discussed.

Changes in DNA, RNA, total lipids, phospholipids, and proteins and the activity of certain enzymes and pattern of their isozymes were studied in Hyalomma dromedarii Koch during embryogenesis. Total proteins fluctuated with a net increase (P less than 0.05) on day 20. Total lipids increased during the first half of embryogenesis and then declined with a net decrease to about 60% of the original level. Total phospholipids decreased to half this original level. DNA content increased greatly during cleavage, gastrulation, and organogeny and RNA increased during cleavage and blastula formation. Glucose-6-phosphate dehydrogenase (G6PDH) activity decreased (P less than 0.05), reaching 20% of its original level on day 12. Malic acid dehydrogenase (MDH) activity remained nearly unchanged throughout embryogenesis. Lactic acid dehydrogenase (LDH) activity increased greatly, with the highest level on day 14 with no further change. Acetylcholinesterase (AchE) activity increased greatly during the first 12 d, with no significant change thereafter. Acid (ACP) and alkaline (ALP) phosphatase activity increased during the first 12 d and declined returning to the original level on day 20. Seven AchE and 5 LDH isozymes were detected during different embryogenesis stages. Two MDH, 2 ACP, 1 ALP, and 2 G6PDH isozymes were detected throughout embryogenesis. Treating the mother with 20-hydroxyecdysone was associated with increases in protein and RNA contents and G6PDH and AchE activity and with decreases in ACP and ALP activity in the embryos.

Mated female Argas (Argas) hermanni Audouin synthesize a gonadotropic hormone in the synganglion within 2 d after feeding. This hormone is then released into the hemolymph. Isolating the ovary from the synganglion by ligation during the period of hormone synthesis interfered with oocyte maturation. Injecting an extract of active synganglia or hemolymph from mated fed females into mated, recently fed, ligated females induced oocyte maturation in their ovaries. In the posterior body region of females ligated 1 h after feeding, total proteins, including hemolymph vitellogenins and ovary vitellins, were unchanged during vitellogenesis. The number of protein fractions, their chemical nature, relative mobility, and relative amounts were similar to those found in normal females 1 h after feeding. These findings suggest that the lack of synganglion gonadotropic hormone inhibits vitellogenin synthesis (or its release into the hemolymph), vitellin production, and oocyte maturation.

An apparently new agent, provisionally named Erve virus, was isolated in 1982 from tissues of three white toothed shrews, Crocidura russula, trapped near Saulges village in Western France. Results of virological and ultrastructural studies suggest that this virus belongs to the Bunyaviridae family and is a Bunyavirus-like agent. Serosurveys indicate that Erve virus had apparently a large geographical distribution in France and infects rodents, insectivores, wild boars (Sus scrofa), red deer (Cervus elaphus), sheep, herring gulls (Larus argentatus) and humans. Blood donors living in the vicinity of the Saulges area exhibit the highest incidence of antibody against Erve virus.

The ribosomes from Argas (Persicargas) arboreus Kaiser, Hoogstraal, and Kohls eggs were isolated, and their ability to initiate protein synthesis in a cell-free system was investigated. A greater proportion of polymeric forms was detected in the ribosome fractions at late embryogenesis than at early embryogenesis. Synthesis of RNA, ribosomal RNA, and ribosomal protein occurred during embryogenesis. The ratio of rRNA/rprotein was 1:1.02–1.15, of purines/pyrimidines was 1:1.06–1.10, and of 6-keto groups/6-amino groups was 1:1. Twenty-one different ribosomal proteins were separated by disk electrophoresis. The requirements for an amino acid-incorporating system from A. arboreus eggs were established. The pH 5 enzymes prepared from the tick eggs successfully supported the incorporation of C14 leucine by isolated ribosomes from A. arboreus eggs. RNase, but not DNase, inhibited the protein activity. The functioning of the A. arboreus ribosomes requires Mg++, GTP, ATP, or all of these.

The biochemical effects of juvenile hormone III (JH III) on developing embryos from treated female Argas (Persicargas) arboreus Kaiser, Hoogstraal and Kohls were examined. Exogenous JH III resulted in a decrease in total proteins (P less than 0.001) only during the first 2 d of embryogenesis. There was no significant difference (P greater than 0.05) between RNA and DNA content in eggs from control and JH III-treated females. No significant difference (P greater than 0.05) was observed between control and JH III eggs in their lipid or phospholipid contents throughout embryogenesis. A total of 14-17 protein bands and 6-8 glycoprotein bands were separated by electrophoresis during embryogenesis of A. arboreus with some differences in mobility ratio between bands from control and JH III eggs. Differences in activity and isozyme patterns of malic acid, lactic acid, glucose 6-phosphate dehydrogenase, acid phosphatase, and alkaline phosphatase were not observed during embryogenesis of control and JH III-treated A. arboreus. Differences were observed in esterase activity.

Vaginal eversion was observed in Argas (Chiropteragas) boueti. During eversion, both cervical and vestibular parts of the vagina are fully everted so that the former is anteriorly oriented, whereas the latter occupies the posterior end of the everted organ. The histology of normal and everted vaginas is described and correlated with its functional and biological significance. Vaginal eversion most likely occurs while the tick is ovipositing and may be involved in the wax-coating process of eggs by Gene's organ.

A survey was conducted to determine the prevalence and identity of virus(es) associated with ticks and California gulls (Larus californicus Lawrence) during July 1984 on islands in Mono Lake, Calif. A total of 800 Argas n. sp. was collected from under rocks associated with nests of this gull and assayed for virus. From 60 pools each containing 10 ticks and from 200 ticks tested individually, 28 isolates of virus recovered in Vero or baby hamster kidney cells were all identified as Mono Lake (ML) virus, both by enzyme-linked immunosorbent assay (ELISA) and polyacrylamide gel electrophoresis (PAGE). Neutralizing antibody to ML virus was detected in serum of 37% (17/46) of the gull chicks and two adult gulls tested. In the laboratory, 1-d-old domestic chickens were susceptible to infection with ML virus and subsequently produced antibody detectable by ELISA. Given an estimated overall infection rate of 4.7% for ticks, the prevalence of neutralizing antibody in young gulls, and the abundance of ticks, the potential for transmission of ML virus to California gulls breeding at Mono Lake would appear to be significant.

Native birds, mostly passerine species, ecologically associated with Culiseta melanura, the enzootic vector of eastern equine encephalomyelitis and Highlands J viruses in the eastern United States, were examined over a 12-year period in southeastern Massachusetts. These studies concentrated on those individual birds known, by banding returns, to be residents of large wooded swamps where both eastern equine encephalomyelitis and Highlands J viruses were known to be enzootic. Of 8,417 birds sampled, 1,227 (14.6%) were recaptured one or more times (mean 2.7 times). Antibody profiles on individuals nesting or feeding in enzootic areas were determined from serial blood samples drawn from these recaptured birds. The duration of detectable neutralizing antibody in these birds was found to be ephemeral in some species (e.g., black-capped chickadees) and extremely longlasting in others (e.g., gray catbirds, swamp sparrows). The significance of these findings to arbovirus surveillance programs is discussed.

Five new isolates of Kemerovo group viruses were recovered from Ixodes uriae collected on Great Island, Witless Bay Seabird Sanctuary, Newfoundland, Canada, during July 1985. This brings the total number of Orbivirus isolates on Great Island to 18 isolates including the 7 from 1971 and 6 from 1972. Genomic segments of several strains were compared by polyacrylamide gel electrophoresis. The degree of variation in each segment of these viruses was calculated. Great Island and Bauline viruses exhibited a great degree of variation in dsRNA migration patterns. Great Island and Bauline genomes averaged 11.60 (SD = 0.107) and 11.69 megadaltons (SD = 0.075), respectively. Variation was observed in all 10 segments of Great Island and Bauline viruses. These findings were compared with serologic and protein gel data.

Brucella abortus is an intracellular bacterium that establishes lifelong infections in livestock and humans although the mechanisms of its chronicity are poorly understood. Activated B cells have long lifespan and B. abortus infection activates B cells. Our results indicate that the direct infection of B cells with B. abortus induced matrix metalloproteinase-9 (MMP-9), receptor activator for NF κB ligand (RANKL), tumor necrosis factor (TNF)-α and interleukin (IL)-6 secretion. In addition, supernatants from B. abortus-infected B cells induced bone marrow-derived monocytes to undergo osteoclastogenesis. Using osteoprotegerin, RANKL's decoy receptor, we determined that RANKL is involved in osteoclastogenesis induced by supernatants from B. abortus-infected B cells. The results presented here shed light on how the interactions of B. abortus with B cells may have a role in the pathogenesis of brucellar osteoarticular disease.

Seven strains of a newFlavivirus, for which the name of Meaban virus is proposed, were isolated from the seabird tickOrnithodoros (A.)maritimus collected during 1981 and 1982 in nests of herring gulls(Larus argentatus) on islands of South Brittany, France. The new virus was compared serologically with 65 other flaviviruses including Tyuleniy virus and was found to be most closely related to, but different from Saumarez Reef virus, an agent previously isolated in Australia and Tasmania. Some general properties of Meaban virus are described and its antigenic relationships with other tick-borne flaviviruses associated with seabirds are discussed.

The accumulated data indicate that mesostomid flatworms are efficient predators of mosquito larvae. This paper presents the 1st published records for 3Mesostoma Ehrenberg, including 2 predators of mosquitoes.Mesostoma californicum Hyman,Mesostoma vernale Hyman, andMesostoma sp. cf.lingua Abildgaard were discovered in a temporary pool in Massachusetts.M. californicum andM. sp. cf.lingua were found to be efficient predators on mosquitoe larvae.

31 Palyam serogroup viruses were examined by complement-fixation and plaque-reduction neutralization tests and by PAGE of the segmented, double-stranded (ds) RNA genome. Although the viruses were indistinguishable by complement-fixation tests, 10 distinct virus serotypes were identified by plaque-reduction neutralization methods. Palyam group viruses which were distinct by the neutralization test had unique dsRNA profiles, whereas those agents which were indistinct by the neutralization test had identical dsRNA profiles. 20 isolations of 3 Palyam serotypes were made from bovines and Culicoides midges in Australia over a 9-year period. When the genome of these isolates was examined electrophoretically, the dsRNA profiles of virus isolates within a given serotype were identical.