Mite-plant associations from the eocene of southern australia.

Acarodomatia or "mite houses" are located on leaves of many present-day angiosperms and are inhabited by mites that may maintain leaf hygiene. Eocene deposits in southern Australia have yielded acarodomatia on fossil leaves of Elaeocarpaceae and Lauraceae and also contain oribatid mites with close affinities to those that inhabit the acarodomatia of the closest living relatives of the fossil plant taxa. The data indicate that mite-plant associations may have been widespread in southern Australia 40 million years ago.

Early land animals in north america: evidence from devonian age arthropods from gilboa, new york.

A new fossil site near Gilboa, New York, is one of only three where fossils of terrestrial arthropods of Devonian age have been found. The new Gilboan fauna is younger than the other two but richer in taxa. Fragmentary remains and nearly whole specimens assigned to Eurypterida, Arachnida (Trigonotarbida, Araneae, Amblypygi, and Acari), Chilopoda [Craterostigmatomorpha(?) and Scuterigeromorpha(?)], and tentatively to Insecta (Archaeognatha) have been found. The centipedes and possible insects may represent the earliest records known for these groups.

Effect of the major histocompatibility complex on the inhibition of induced cellulitis development in a broiler chicken model.

The chicken major histocompatibility complex (MHC) has been implicated in conferring resistance or susceptibility to several bacterial, parasitic, and viral diseases, the most notable of which is Marek's disease. In Marek's disease certain MHC haplotypes have been shown to confer relative resistance (B21), whereas other haplotypes are susceptible (B13). Relatively little work has been performed looking at the association of the MHC with bacterial diseases. One such disease is cellulitis, which is caused by several different bacteria but most notably by Escherichia coli. In this report, a commercial broiler chicken line known to contain standard B13 and B21, as well as the unique MHC types BA9 and BA12, was examined in a challenge model for cellulitis. The MHC-defined birds were challenged with a cellulitis-causing E. coli isolate and the frequency of lesion development and severity was quantified. In conclusion, B21 had the highest incidence of cellulitis development, B13 had the lowest incidence, and BA9 and BA12 had intermediate results. Results concerning the lesion severity showed that it was independent of the birds' MHC type.

Development of a polymerase chain reaction assay for specific identification of Clostridium colinum.

Clostridium colinum is the causative agent of ulcerative enteritis, a serious disease of the bobwhite quail (Colinus virginianus) and sporadically of young chickens. The aim of the present study was to develop a polymerase chain reaction (PCR) assay specific for C. colinum identification. The 16S rDNA sequence of C. colinum was analysed and two species-specific primers were designed. The specificity of these primers was tested with closely related Clostridium species and the expected amplified product (935 base pairs) was observed only with DNA from samples containing C. colinum. Results from performing PCR assays on faecal samples from quails spiked with different concentrations of C. colinum, showed that the detection limit of the assay was 1.6 x 10(4) colony-forming units per gram of faecal material. This PCR assay can be used in diagnostic laboratories to confirm the presence of C. colinum in pure cultures and could be used to screen enriched samples or faecal samples for the presence of this pathogen.

Evaluation of different plate media for direct cultivation of Campylobacter species from live broilers.

Accurate identification and optimal culturing procedures for Campylobacter spp. from live broilers are needed for epidemiological studies. Because there is no standardized protocol, we designed and conducted studies to evaluate different selective media for the culturing and isolation of Campylobacter spp. from cecal and fecal samples obtained from battery-reared and commercial broilers. Five media selective for Campylobacter were evaluated: Campylobacter agar base, Campylobacter, Campy-Line, modified Campy-Cefex, and modified charcoal cefoperazone deoxycholate agar. With contaminated broilers reared in battery cages, Campylobacter agar base, Campylobacter, modified Campy-Cefex, and modified charcoal cefoperazone deoxycholate agar revealed similar isolation rates (P > 0.05), whereas Campy-Line showed a lower efficacy (P < 0.05). With commercial live broilers, modified Campy-Cefex agar was more consistent for the isolation of Campylobacter from feces, whereas modified Campy-Cefex and modified charcoal cefoperazone deoxycholate agar showed similar isolation rates from cecal samples. Campy-Line agar showed a lower identification rate (P < 0.05) for both fecal and cecal samples. A multiplex PCR assay used for identification showed that Campylobacter jejuni and Campylobacter coli DNA was present in the samples. Pulsed field gel electrophoresis restriction profiles differed among samples collected from different commercial farms but were similar for isolates from the same farm, suggesting clonal differences. No variation was seen in pulsed field gel electrophoresis patterns among isolates cultured on different media. Our data suggest that the choice of plate medium may influence the efficiency of isolating Campylobacter spp. from broiler chickens by direct plating from fecal or cecal samples.

A longitudinal study of Salmonella and Campylobacter jejuni isolates from day of hatch through processing by automated ribotyping.

Comparisons of bacterial populations over long periods of time allow researchers to identify clonal populations, perhaps those responsible for contamination of farms or humans. Salmonella and Campylobacter can cause human illness, and our objective was to use a library typing system to track strains that persist in the poultry house and through the processing plant. Two farms, over four consecutive flocks, were studied. Multiple samples were taken of the poultry house environment, feed mill, transport crates, and carcasses in the processing plant. Sample collection on the farm took place on chick placement day, midgrowout, and the day of harvest. This study found that 80.3% of isolates belonged to a single strain of Salmonella Kentucky that persisted in several environmental samples for all flocks at both farms, from chick placement day to the final product at the plant. Surgical shoe covers produced most isolates (n = 26), and processing day yielded the highest recovery (n = 68). Additional serotypes were recovered, but the Salmonella Kentucky-positive eggshells and chick mortality appeared to be the source of the organism for both farms. All Campylobacter isolates recovered were identified as C. jejuni. Most Campylobacter isolates (90.1%) belonged to one of three core strains. C. jejuni was not recovered on chick placement day. Cecal droppings yielded all nine strains. Most isolates (98.2%) were from one farm. Cluster analysis grouped C. jejuni and Salmonella isolates into four and six distinct clusters, respectively, on the basis of a similarity level of 80%.

Streptozocin-treated Verner-Morrison Syndrome: plasma vasoactive intestinal peptide and tumor responses.

A patient with watery diarrhea, hypokalemia, hypochlorhydria, and a non-beta islet cell carcinoma of the pancreas (Verner-Morrison syndrome) was found to have an elevated vasoactive intestinal peptide (VIP) concentration in the plasma as well as in the tumor. Treatment with streptozocin resulted in a dramatic subjective and objective tumor response in this patient. Plasma VIP concentration fell into the normal range after four courses of treatment, diarrhea ceased after the third course of therapy, and measurable tumor mass markedly decreased during that same period of time. The patient remains in clinical remission with no evidence of tumor regrowth 18 months after the beginning of treatment. In this patient, plasma VIP measurements were an excellent marker of tumor activity and correlated well with objective disease measurements and clinical response.

Concerning the role of 24,25-dihydrolanosterol and lanostanol in sterol biosynthesis by cultured cells.

Rat hepatoma cells (H4-II-E-C3) efficiently converted a dietary supplement of [2-3H]24,25-dihydrolanosterol (1) to [3H]cholesterol while [2-3H]lanostanol (4,4,14 alpha-trimethylcholestanol (2) was recovered from the cells without apparent transformation, although it was esterified and induced an accumulation of lanosterol. A comparison of the chromatographic (TLC, GLC and HPLC), spectral (MS and 1H-NMR) and physical properties of 1 and 2 is given for the first time. The inability to detect 2 in nature coupled with our findings that 1 but not 2 is metabolized to cholesterol by H4 cells is interpreted to imply that the biosynthetic inclusion of the delta 8(9)-bond during the cyclization process of squalene-oxide to a tetracyclic product is an evolutionary adaptation selected for because the olefinic linkage is structually important in the subsequent conversion of lanosterol and its stereoisomers, e.g., cycloartenol, to delta 5-sterols.

The association of various isolates of Escherichia coli from the United States with induced cellulitis and colibacillosis in young broiler chickens.

An experiment was conducted to observe the effects of 10 different avian Escherichia coli isolates in 3-day post-hatch broiler chicks after subcutaneous administration. Isolates were originally obtained from various avian sources throughout the US. Chicks were injected subcutaneously on the ventral surface and necropsied at 7-day intervals for 3 weeks. Cellulitis was produced in all treatments receiving E. coli of cellulitis origin, with the highest incidence occurring 2 weeks post-infection in birds that received an isolate recovered in a previous challenge experiment. Cellulitis was also observed at week 1 post-infection in a small percentage of the birds in two of the treatments receiving E. coli of enteric origin, although lesions disappeared from the group after week 1 post-infection. Septicaemia was the most frequent sequel to challenge and occurred regardless of which isolate was injected. Chicks exposed to cellulitis origin isolates developed septicaemia more frequently than birds challenged with E. coli of non-cellulitis origin. The data implies that cellulitis is unlikely to occur early in the bird's life, since young birds exposed to E. coli frequently develop septicaemia.

Scratches as a component in the pathogenesis of avian cellulitis in broiler chickens exposed to cellulitis origin Escherichia coli isolates collected from different regions of the US.

Cellulitis was induced in broiler chickens in two experiments. Birds were placed on used pine-shaving litter at day of hatch and raised to 28 days of age, at which time one-half the birds in each pen were scratched and the litter was treated with either one of seven cellulitis origin Escherichia coli (collected from various locations in the US) or sterile saline. Although minor differences could be detected in the association of specific regional isolates with differing rates of cellulitis, all isolates were capable of inducing cellulitis in a preponderance of the scratched birds. These same isolates were not capable of producing cellulitis in birds that were not scratched by design, confirming the importance of scratches in the pathogenesis of cellulitis. Those birds in the unscratched groups placed on litter inoculated with either a cellulitis E. coli isolate (EC-AR1) or sterile saline that did develop cellulitis lesions showed the remnants of healed scratches which had occurred naturally during the course of the growout, again providing evidence as to the importance of scratches in the development of cellulitis.

The effects of early exposure of cellulitis-associated Escherichia coli in 1-day-old broiler chickens.

Two experiments were performed to test the effect of various field strains of Escherichia coli of cellulitis origin. In the first experiment, 1-day-old broiler chicks were challenged with one of two E. coli field strains using inoculation routes including oral gavage, swabbing of the navel and subcutaneous injection. No cellulitis lesions were produced, although the birds experienced high levels of septicemia/toxemia, characteristic of colibacillosis. The birds that received the E. coli by subcutaneous injection experienced the highest rate of mortality, while those that were challenged by gavage and those that had their navels swabbed experienced lesser rates of mortality. Birds in the second experiment were challenged at 1 day of age with one of three field strains of cellulitis-origin E. coli administered alone or in combination (1:1), which were serially diluted prior to subcutaneous injection. No significant differences in body weight, mortality or cellulitis rates were associated with specific isolates given; however, significant differences were seen with mortality and cellulitis rates according to the dilution of bacteria given. A linear effect was also noted with body weight at 3 weeks, again correlating to the dilution of bacteria that the chicks received.

The influence of Escherichia coli strains from different sources and the age of broiler chickens on the development of cellulitis.

In two experiments, broilers were challenged with one of several field strains of Escherichia coli to determine whether the source of the E. coli and age of the bird at time of inoculation affected the development of cellulitis lesions. In the first experiment, birds inoculated at 52 days of age with E. coli of faecal, airsacculitis and cellulitis origin exhibited a cellulitis lesion incidence of 47.5, 25 and 77.5%, respectively. This study confirms earlier observations that E. coli strains isolated from cellulitis lesions express a higher propensity for producing these same lesions than other strains, including those associated with airsacculitis. In the second experiment, birds were inoculated at 4, 7, 10, 16, 28, and 52 days of age with an E. coli strain of cellulitis origin and necropsied 2 days post-infection. The resulting incidence of cellulitis ranged from 20% (day 7) to 95% (days 16 and 28), indicating that cellulitis can develop in any age of bird, although the lesions were frequently associated with other manifestations of colibacillosis (perihepatitis, pericarditis, airsacculitis) in birds challenged from 4 to 16 days of age.

Effect of Carotenoids on Aflatoxin B(1) Synthesis by Aspergillus flavus.

ABSTRACT Carotenes and xanthophylls occurring in yellow corn and related terpenoids were tested for their effect on growth and aflatoxin B(1) production by Aspergillus flavus NRRL 3357, using the suspended disc culture method. Aflatoxin synthesis was inhibited at concentrations of beta-carotene, lutein, and zeaxanthin comparable to those found in the horny endosperm of mature corn. Usually growth was not significantly affected. Inhibition of aflatoxin biosynthesis was greater for compounds with an alpha-ionone-type ring (alpha-carotene, lutein, or alpha-ionone) compared with compounds with a beta-ionone ring. The presence of hydroxy groups on the rings tended to decrease inhibition, but did not override the effect of the ring type; lutein was similar to alpha-carotene and zeaxanthin was similar to beta-carotene in inhibition. A mutant accumulating norsolorinic acid (NA), A. parasiticus SRRC 162, incubated with alpha-carotene produced reduced levels of both NA and aflatoxin, indicating that inhibition occurred before NA. Additional A. flavus strains tested against 50 mug/ml of beta-carotene had 89 to 96% inhibition, which was significantly more sensitive than NRRL 3357. A. parasiticus strains were less sensitive and generally had similar or lower inhibition than NRRL 3357. The results indicate that the presence of carotenoids in endosperm may decrease the amount of aflatoxin produced by A. flavus.

Inhibition of aflatoxin B(1) biosynthesis in Aspergillus flavus by anthocyanidins and related flavonoids.

Anthocyanidins and precursors or related flavonoids were tested at concentrations from 0.3 to 9.7 mM ( approximately 0.1-3.0 mg/mL) for activity against growth and aflatoxin B(1) biosynthesis by Aspergillus flavus Link:Fr. NRRL 3357. Aflatoxin B(1) production was inhibited by all anthocyanidins tested, and 3-hydroxy compounds were more active than 3-deoxy forms. Monoglycosides of cyanidin were 40% less inhibitory than the aglycon, whereas a monoglucoside and a diglucoside of pelargonidin were 80 and 5%, respectively, as active as the aglycon. Of eight flavonoids tested, only kaempferol was moderately active, whereas luteolin and catechin were weakly inhibitory. Binary combinations of delphinidin and three other aflatoxin inhibitors acted independently of each other. Results with an aflatoxin pathway mutant indicated that anthocyanidin inhibition occurred before norsolorinic acid synthesis.

Isoform patterns of chitinase and beta-1,3-glucanase in maturing corn kernels (Zea mays L.) associated with Aspergillus flavus milk stage infection.

Isoform patterns of chitinase and beta-1,3-glucanase of maturing kernels of yellow dent corn (Pioneer 3394) infected with Aspergillus flavus at the milk stage were investigated through polyacrylamide gel electrophoresis (PAGE). Proteins on the sodium dodecyl sulfate (SDS) gel with an apparent molecular mass range of 23-46 kDa were differentially present in the kernels infected with both aflatoxin-producing and non-aflatoxin-producing strains of A. flavus. From in-gel (native PAGE) enzyme activity assays, three bands corresponding to chitinase isoforms and two bands corresponding to beta-1,3-glucanase isoforms were detected in the infected kernels. One chitinase isoform of 29 kDa was present only in the infected kernels, and another one of 28 kDa was present in both infected and noninfected kernels. They were judged to be acidic on the basis of their migration on an acrylamide isoelectric focusing (IEF) gel. For the beta-1,3-glucanase, one isoform of 35 kDa was present in both infected and noninfected kernels, but another one, a 33 kDa isoform, was present only in the infected kernels. Both acidic and basic beta-1,3-glucanase isoforms were detected in the IEF gel. The results of this study are the first to demonstrate patterns of enhanced or inducible proteins in maturing corn kernels in response to A. flavus infection at the milk stage. The results also indicate that only particular isoforms of the two hydrolytic enzymes are involved in the maturing corn kernels infected at the milk stage with A. flavus.

Quantitation of steryl ferulate and p-coumarate esters from corn and rice.

The principal steryl ferulate and p-coumarate esters of different fractions from processed corn brans and corn oils, unrefined and refined, and from rice bran and rice bran oil were quantified by high-performance liquid chromatography. The results show that hexane-extracted corn oils yield more than five times the amount of esters compared to expeller processed oils. The yields of esters from bran and related products ranged from 0.07 to 0.54 mg/g of bran. Unrefined corn oils had levels from 0.18 to 8.6 mg/g for oil from hexane-extracted bran. By comparison, rice bran had ester levels of 3.4 mg/g of bran, and rice bran oil had levels of 15.7 mg/g of oil. The predominant esters from corn were sitostanyl and campestanyl ferulate, and sitostanyl and campestanyl p-coumarate. The principal esters from rice bran were cycloartenyl, 24-methylenecycloartanyl, and campesteryl ferulate. Rice bran oils had low levels of 24-methylenecycloartanyl but high levels of cyclobranol esters. The data presented provide a direct comparison of steryl ferulate and p-coumarate levels in the two cereals, and will aid in selecting the most suitable sources for the isolation of these compounds from corn products.

Sterol utilization and metabolism by Heliothis zea.

Heliothis zea (corn earworm), an insect that fails to synthesize sterols de novo, was reared on an artificial diet treated with 18 different sterol supplements. Larvae did not develop on a sterol-less medium. delta 5-Sterols with a hydrogen atom, a methylene group, an E- or Z-ethylidene group, or an alpha- or beta-ethyl group (cholesterol, ostreasterol, isofucosterol, fucosterol, sitosterol, and clionasterol, respectively) at position C-24, and delta 5-sterols doubly substituted in the side chain at C-24 with an alpha-ethyl group and at C-22 with a double bond (stigmasterol) supported normal larval growth to late-sixth instar (prepupal: maturity). The major sterol isolated from each of these sterol treatments was cholesterol, suggesting that H. zea operates a typical 24-dealkylation pathway. The sterol requirement of H. zea could not be met satisfactorily by derivatives of 3 beta-cholestanol with a 9 beta, 19-cyclopropyl group, gem dimethyl group at C-4, a delta 5,7-bond or delta 8-bond, or by side chain modified sterols that possessed a delta 25(27)-24 beta-ethyl group, delta 23(24)-24-methyl group or 24-ethyl group, or delta 24(25)-24-methyl or 24-ethyl group. The major sterol recovered from the larvae (albeit developmentally arrested larvae) treated with a nonutilizable sterol was the test compound. Sterol absorption was related to the degree of sterol utilization. The most effective sterols absorbed by the insect ranged from 27 to 66 micrograms per insect, whereas the least effective sterols absorbed by the insect ranged from 0.6 to 6 micrograms per insect. Competition experiments using different proportions of cholesterol and 24-dihydrolanosterol (from 9:1 to 1:9 mixtures) indicated that abnormal development of H. zea may be induced on less than a 1 to 1 mixture of utilizable (cholesterol) to nonutilizable (24-dihydrolanosterol) sterols. The results demonstrate new structural requirements for sterol utilization and metabolism by insects, particularly with respect to the position of double bonds in the side chain and functionalization in the nucleus. The novel sterol specificities observed in this study appear to be associated with the dual role of sterols as membrane inserts (nonmetabolic) and as precursors to the ecdysteroids (metabolic).

Pathogenicity of a strain of Trichomonas gallinarum in turkeys and its possible interaction with cecal coccidia.

The pathogenicity of Trichomonas gallinarum (TG) in turkeys and chickens was assessed in a series of four experiments. TG was shown to be resistant to freezing for a period of 1 hr at -20 C; birds administered an emulsion of previously frozen TG were readily infected. Young birds receiving this inoculum were more likely to be infected with TG in both ceca compared with birds administered TG emulsion that had remained at room temperature for the same length of time. In this and other experiments, birds infected with the parasite consistently produced a yellow frothy liquid in the ceca, as well as small raised papulae on the mucosal surface of the ceca. Histologically, the lesions were located in the lamina propria, with openings that extended from the apex of the lesion to the crypts. The lamina propria was consistently infiltrated by lymphocytes and scattered heterophiles. Although TG is likely involved in the pathogenesis of the lesions, the resulting pathology could not be linked definitively to TG alone because inoculation was performed with a cecal contents homogenate containing significant numbers of cecal bacteria. Combined infections of TG and Eimeria adenoides (EA) were also studied. Turkeys administered both parasites were more frequently infected with TG in both ceca compared with those that received TG alone. Ceca infected with TG alone tended to be enlarged and gas filled, whereas those infected with the combination of TG and EA were smaller and usually lacked the yellow frothy liquid contents.

Studies on the effect of concurrent infections of Ascaridia dissimilis and Eimeria meleagrimitis in turkeys.

The effects of concurrent infections of Ascaridia dissimilis and Eimeria meleagrimitis in turkeys were studied in two separate trials. In the first trial, newly larvated ova were used to inoculate poults 7 or 3 days before, on the same day as, or 3 days after the poults received E. meleagrimitis. Poults receiving the A. dissimilis 3 days before, on the same day as, or 3 days after receiving E. meleagrimitis had significantly lower total oocyst production than the E. meleagrimitis-positive control. In the second trial, larvated ova that were approximately 100 days old were used in the same regimen. In this trial, poults that were inoculated with A. dissimilis 3 days before or 3 days after receiving the E. meleagrimitis produced significantly fewer oocysts than poults inoculated simultaneously with both parasites. Poults inoculated with A. dissimilis 3 days before receiving E. meleagrimitis also had significantly fewer third-stage nematodes than the A. dissimilis-positive controls. There were no significant differences in weight gain between treatments in either trial.

A reproducible model for the induction of avian cellulitis in broiler chickens.

Avian cellulitis was reproduced in 39-day-old broilers by subcutaneous injection of Escherichia coli originally isolated from a cellulitis lesion. One hundred percent of the birds injected with the isolate on the dorsal and ventral surfaces developed characteristic fibrino-caseous plaques. A slightly lower percentage (90%) of the birds injected subcutaneously in the inguinal area developed the same lesions. Only 30% of the birds that had been inoculated by scratching the skin and swabbing the bacterial inoculum onto the wound developed the lesion. No birds inoculated by swabbing the inoculum onto a feather follicle, from which the feather had been pulled, developed cellulitis. Characteristic cellulitis plaques could be produced as early as 18 hr postinfection (PI). Lesions, consisting of a serosanguinous, yellow-pink-to-orange-tinged fluid appeared as early as 6 hr PI. The lesions progressed, changing to a more thin, yellow, purulent fluid by 12 hr PI followed by plaque formation. Although there was a trend for lesion size to diminish with time, the majority of the challenged birds, examined as late as 3 wk PI, still had prominent cellulitis plaques. Lesions in birds injected subcutaneously on the dorsal surface sometimes extended into other regions of the body, including the abdominal region, and thereby resembled the type of lesions that have previously been described as type I or hatchery-borne cellulitis.