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C L Bailey

Publications and source records attributed to C L Bailey.

At least 55 records · Page 3Linked to original sources
PubMed1987

Increased dissemination of dengue 2 virus in Aedes aegypti associated with concurrent ingestion of microfilariae of Brugia malayi.

We investigated whether concurrent ingestion of dengue 2 virus and microfilariae of Brugia malayi would increase viral infection and dissemination rates in Aedes aegypti. Infection rates were similar in mosquitoes that ingested virus alone or both virus and microfilariae concurrently. However, viral dissemination rates, as determined by recovery of dengue virus from both legs and bodies separately, were significantly greater in mosquitoes that ingested both agents concurrently than in those that ingested virus alone. This study confirms that vectorial capacity of a natural vector of an arbovirus may be enhanced by the concurrent ingestion of microfilariae.

Aedes↗
PubMed1987

Reduced survival of adult Culex pipiens infected with Rift Valley fever virus.

The effect of Rift Valley fever (RVF) viral infection on the survival of female Culex pipiens was examined. In 3 experiments in which mosquitoes ingested RVF virus, there was a 44% decrease in survival to days 14-16 for transmitting vs. nontransmitting mosquitoes, and a 48% decrease in survival for individuals with disseminated vs. nondisseminated infections. These results were corroborated by other experiments in which survival of mosquitoes intrathoracically inoculated with RVF virus was compared with that of those inoculated with diluent. In both the per os and inoculation tests, uninfected mosquitoes survived significantly longer than infected mosquitoes. Even though mosquitoes with disseminated infections had a lower survival rate than did uninfected mosquitoes, dissemination and transmission rates were similar at days 7 and 14-18 after the infectious bloodmeal. This suggests that nondisseminated individuals were developing disseminated infections and becoming capable of transmitting virus between days 7 and 14-18 at approximately the same rate older transmitters were dying. The decreased survival associated with RVF viral infection should be considered in predictive models of this disease.

Animals↗
PubMed1986

Use of the avidin-biotin-peroxidase complex immunocytochemical procedure for detection of Rift Valley fever virus in paraffin sections of mosquitoes.

The avidin-biotin-peroxidase complex (ABC) immunocytochemical procedure was used to locate Rift Valley fever (RVF) virus antigen in infected Aedes albopictus C6/36 cultured cells and in serial paraffin sections of intrathoracically-injected Egyptian Culex pipiens. Fixation of the cultured cells in formaldehyde or periodate-lysine-paraformaldehyde, and fixation of whole mosquitoes with formaldehyde resulted in good preservation of morphology and excellent differential staining between uninfected and infected specimens. Two primary antibodies against RVF virus were tested on the cultured cells: a polyclonal rabbit antiserum and a mixture of mouse monoclonal antibodies. Only the mouse monoclonal antibody mixture was tested on the Cx. pipiens. Specific staining of tissues in paraffin sections occurred at dilutions as high as 1:5,000. In both cultured Ae. albopictus cells and sections of Cx. pipiens, only the cytoplasm was positive for antigen. A preliminary list of tissues in Cx. pipiens that exhibited specific or nonspecific staining is given.

Aedes↗
PubMed1986

Identification of Aedes campestris from New Mexico: with notes on the isolation of western equine encephalitis and other arboviruses.

An arbovirus survey was conducted during August 1985 at White Sands Missile Range in southcentral New Mexico following a suspected arboviral disease epizootic among feral horses. A total of 20,566 mosquitoes (18,505 females and 2,061 males) and 8,900 biting gnats were collected and assayed for virus. Female mosquitoes were principally Aedes campestris (54.8%), Aedes dorsalis (30.4%) and Culex tarsalis (13.2%). Arboviruses were not isolated from biting gnats, but mosquitoes yielded a total of 37 viral isolates, including western equine encephalitis (WEE) (18), California serogroup (15), Cache Valey (1), and Hart Park (1) viruses in addition to 2, as yet unidentified, rhabdoviruses. Isolates of WEE virus were from 9 pools of Ae. campestris, 6 of Cx. tarsalis and 3 of Ae. dorsalis. California serogroup viruses, including 2 subtypes, were obtained from 7 pools of females and 1 pool of males of Ae. campestris and from 4 pools of Ae. dorsalis. Cache Valley and Hart Park viruses were isolated from single pools of Ae. dorsalis and Cx. tarsalis, respectively, and the rhabdoviruses were obtained from Ae. campestris and Psorophora signipennis.

Aedes↗
PubMed1985

Rift Valley fever virus (family Bunyaviridae, genus Phlebovirus). Isolations from Diptera collected during an inter-epizootic period in Kenya.

A total of 134 876 Diptera collected in Kenya during a 3-year period were tested in 3383 pools for Rift Valley fever (RVF) virus. Nineteen pools of unengorged mosquitoes were found positive for RVF. All isolations were made from specimens collected at or near the naturally or artificially flooded grassland depressions that serve as the developmental sites for the immature stages of many mosquito species. The isolation of virus from adult male and female A. lineatopennis which had been reared from field-collected larvae and pupae suggests that transovarial transmission of the virus occurs in this species.

Aedes↗
PubMed1985

Enhanced mosquito blood-finding success on parasitemic hosts: evidence for vector-parasite mutualism.

The generalized hematopathology frequently found in animals infected with vector-borne pathogens may maximize transmission by enhancing the ability of vectors to locate blood in infected hosts. We tested this idea of mutualism between parasite and vector by comparing duration of probing of mosquitoes feeding on noninfected and on malaria-(Plasmodium chabaudi) or arbovirus-(Rift Valley fever virus) infected animals. We found that median duration of probing (blood location) on infected rodents was reduced by at least 1 min as compared to noninfected rodents. This enhanced ability of vectors to locate blood, possibly caused by parasite-disrupted hemostasis, may be a common feature of vector-borne diseases.

Aedes↗
PubMed1985

Effect of extrinsic incubation temperature on the ability of Aedes taeniorhynchus and Culex pipiens to transmit Rift Valley fever virus.

Studies were conducted to examine the effects of extrinsic incubation (EI) temperature on the vector competence of Egyptian Culex pipiens and North American Aedes taeniorhynchus for Rift Valley fever (RVF) virus. Following per os exposure, infection rates in Ae. taeniorhynchus remained relatively constant at 55%, 56%, and 59% for mosquitoes held at EI temperatures of 13, 26, and 33 degrees C, respectively. In contrast, significantly fewer Cx. pipiens became infected when held at 13 degrees C (38%), than when held at 26 degrees C (75%) or 33 degrees C (91%). In both species, viral dissemination and transmission occurred earlier in mosquitoes held at high temperatures as compared to those held at low temperatures. Following EI at 26 or 33 degrees C, Cx. pipiens were able to transmit virus as early as 1 day after inoculation with RVF virus. However, 3 days were required before the first transmissions by inoculated Ae. taeniorhynchus. Temperature of EI affected these 2 species differently in their ability to transmit RVF virus. Because of the importance of EI temperature on infection and transmission rates, as well the length of the EI period, the role of EI temperature will need to be evaluated for each virus and vector pair.

Aedes↗
PubMed1985

Mechanical transmission of Rift Valley fever virus by hematophagous Diptera.

Experimental studies were conducted to determine if hematophagous Diptera were capable of mechanical transmission of Rift Valley fever (RVF) virus to laboratory animals. All species tested (Glossina morsitans, Aedes aegypti, Aedes taeniorhynchus, Culex pipiens, Stomoxys calcitrans, Lutzomyia longipalpis, and Culicoides variipennis) mechanically transmitted the virus to hamsters. Mechanical transmission rates for G. morsitans ranged from 0-100%, with the probability of mechanical transmission positively correlated with initial viremia titer and negatively correlated with the time after virus exposure. Mechanical transmission of RVF virus to lambs was demonstrated with both G. morsitans and Cx. pipiens. These findings demonstrated that mechanical transmission of RVF virus by hematophagous flies may contribute to the natural transmission and dissemination of this virus.

Aedes↗
PubMed1984

Enhanced arboviral transmission by mosquitoes that concurrently ingested microfilariae.

Infection, dissemination, and transmission of an arbovirus in mosquitoes are enhanced by concurrent ingestion of microfilariae. Ingestion of Rift Valley fever virus alone infected only 64 percent of female Aedes taeniorhynchus. Of these, only 5 percent of refeeding mosquitoes actually transmitted virus. In contrast, ingestion of the same amount of virus from concurrently microfilaremic (Brugia malayi) gerbils resulted in 88 percent infection and 31 percent transmission. Enhanced transmission of virus may be attributed to increased transit of virus across the midgut wall. Endemic filariasis may promote arbovirus transmission in nature.

Aedes↗
PubMed1984

Increased mosquito feeding on Rift Valley fever virus-infected lambs.

Experiments were conducted to determine whether or not mosquitoes exhibited an increase in feeding on Rift Valley fever (RVF) virus-infected lambs as compared to uninfected ones. Overall, when given a choice between a viremic lamb, or its uninfected twin, 65% (1,264/1,943) of the engorged female Culex pipiens obtained blood from the viremic lamb. This excess of feedings on viremic lambs was demonstrated regardless of the age of the lambs, or the time period between inoculation of the lambs and exposure to mosquitoes. With 3-day-old and 6- to 8-week-old lambs, 66% of the mosquitoes obtained blood from the viremic lamb. At 28, 48, and 52 hours after infection, the percentages of mosquitoes feeding on viremic lambs were 72, 68, and 64, respectively. Temperature, as measured by the difference in temperature of the viremic lamb minus that of the control lamb, was positively correlated with mosquito feedings on young lambs (3 days old), but not on older lambs (6 to 8 weeks old). When Cx. pipiens and Aedes taeniorhynchus were simultaneously given the opportunity to feed on 3-week-old lambs, a significantly higher percentage of engorged Cx. pipiens (94/108, 87%) fed on the viremic lamb than did engorged Ae. taeniorhynchus (187/350, 53%). The data generated by this study (e.g., an excess of feedings on the viremic lambs) warrant further study to determine the significance of this observation under field conditions.

Aedes↗
PubMed1984

Replication and dissemination of Rift Valley fever virus in Culex pipiens.

Following ingestion of 10(4.2) to 10(7.2) plaque-forming units (PFU) of Rift Valley fever (RVF) virus, 662 of 850 female Culex pipiens (78%) became infected. Those mosquitoes that became infected separated into two distinct groups: 1) those with a nondisseminated infection limited to the gut, and 2) those with a disseminated infection. The former group contained a median of 10(3.2) PFU, while those females with a disseminated infection contained a median of 10(5.5) PFU. Only those females with a disseminated infection were capable of transmitting virus by bite to a susceptible hamster. This is consistent with a mesenteronal escape barrier to viral dissemination. Following intrathoracic inoculation of RVF virus, all females developed a disseminated infection (26/26) and successfully transmitted virus by bite (49/49) if allowed to feed on a susceptible hamster or suckling mouse. Examination of legs and bodies separately provided a rapid and efficient method of determining dissemination status.

Animals↗
PubMed1984

Replication of Rift Valley fever virus in the sand fly Lutzomyia longipalpis.

Rift Valley fever virus was shown to replicate in Lutzomyia longipalpis after intrathoracic inoculation. Viral titers peaked at approximately 4 days postinoculation [mean titer = 10(4.0) plaque forming units (PFU)] and remained relatively constant through day 7. A minimum of 6 of 326 sand flies transmitted virus by bite to susceptible hamsters after 5-9 days of extrinsic incubation. Viral titers of sand flies exposed per os declined steadily through day 9. None of 378 flies that had ingested approximately 10(4.0) PFU of virus transmitted virus when refed on susceptible hamsters.

Animals↗
PubMed1984

"Viable motheaten," a new allele at the motheaten locus. I. Pathology.

A new spontaneous autosomal recessive mutation has recently occurred at the motheaten (me) locus on Chromosome 6 in strain C57BL/6J mice. Homozygotes for the new allele, designated "viable motheaten" (mev), have a mean life span of 61 +/- 2.4 days, compared with only 22 +/- 1.3 days for C57BL/6J-me/me mice. Like the original motheaten mutation, the immediate cause of death in mev/mev mice appears to be severe pneumonitis associated with accumulations of macrophages, granulocytes, and lymphocytes in the lungs. However, because of its longer life span, progression of the disease in mev/mev mice is more amenable to investigation. Eosinophilic crystalline material in alveolar macrophages from mev/mev mice is associated with extravasation of erythrocytes into alveoli. These crystals are morphologically indistinguishable from hematoidin, which results from hemoglobin breakdown following uptake of erythrocytes by macrophages. Severe macrocytic hypochromic anemia with abnormalities in size and shape of erythrocytes develops by 7 weeks. A two-fold increase in peripheral leukocyte count and a five-fold increase in the percentage of neutrophils is seen by 10 weeks. Viable motheaten mice develop focal granulocytic skin lesions by 4 days of age, show depletion of cells from the thymus cortex by 4 weeks, and lack lymphoid follicles in the lymph nodes, spleen, and Peyer's patches. Excessive erythropoiesis and myelopoiesis in the spleen result in marked splenomegaly. Lymph nodes and spleens from mev/mev mice contain increased numbers of plasma cells by 3 weeks; and by 6 weeks, large numbers of atypical plasma cells with Russell bodies are evident. Development of glomerulonephritis by 10 weeks is characterized by granular depositis of immunoglobulin and complement within glomeruli. A twofold increase of blood urea nitrogen levels is present by 15 weeks. Sterility of male mev/mev mice is associated with Leydig cell depletion in the testes, lowered testosterone levels, and impaired spermatogenesis.

Alleles↗
PubMed1983

The effect of laboratory colonization on the vector-pathogen interactions of Egyptian Culex pipiens and Rift Valley fever virus.

Field and laboratory findings implicated Culex pipiens as a vector of Rift Valley fever (RVF) virus during the 1977-1978 epizootics/epidemics in Egypt. This study evaluated changes in infection and transmission rates, and viral titers in F1 through F16 generation Cx. pipiens mosquitoes orally infected with RVF virus. Infection and transmission rates of RVF virus by this species changed significantly during the colonization process. However, the ultimate viral titers of either the transmitting or the infected nontransmitting mosquitoes were not affected by the colonization process. Following ingestion of virus, Cx. pipiens could be separated into three distinct subpopulations, an uninfected group and two types of infected mosquitoes--transmitters and nontransmitters. Transmitters contained significantly more virus (approximately 100-fold) than nontransmitters. These results demonstrated that not every infected female mosquito should be considered a competent vector, even if the species (population) is known to be a primary vector. Transmission was also accomplished by probing mosquitoes which were unsuccessful in obtaining a blood meal. These data document the long-held suspicion that vector competence studies based upon laboratory-colonized specimens may not represent the field situation.

Animals↗
PubMed1983

Hematopoietic stem cell function in motheaten mice.

Mice homozygous for the autosomal recessive mutation "motheaten" have normal numbers of multipotential hematopoietic stem cells in the bone marrow and spleen as determined by spleen colony assay. Histologic examination shows no qualitative abnormality in morphology of stem cell colonies in recipients of bone marrow or spleen cells from motheaten mice. Despite the apparently normal ontogeny, distribution, and differentiative capacity of CFU stem cells, bone marrow and spleen cells from motheaten mice fail to save congenic +/+ lethally gamma-irradiated hosts. This impaired lifesparing capacity is not due to defective self-renewal but appears to be due in part to pulmonary hemorrhage from alveolar capillaries in the gamma-irradiated hosts. Treatment of motheaten mice with 500 R gamma-irradiation followed by reconstitution with normal bone marrow cells increases the lifespan of this mutant to 10 months of age. The early onset of pneumonitis and subsequent short lifespan of motheaten mice is determined at the level of progenitor cells in the bone marrow.

Animals↗