Egg Transmission Research Articles

Epigenetic transgenerational inheritance of toxicant exposure-specific non-coding RNA in sperm.

Environmentally induced epigenetic transgenerational inheritance of phenotypic variation and disease susceptibility requires the germ cell (sperm or egg) transmission of integrated epigenetic mechanisms involving DNA methylation, histone modifications, and non-coding RNA (ncRNA) actions. Previous studies have demonstrated that transgenerational exposure and disease-specific differential DNA methylation regions (DMRs) in sperm are observed and that ncRNA-mediated DNA methylation occurs. The current study was designed to determine if transgenerational exposure-specific ncRNAs exist in sperm. Specifically, toxicants with distinct mechanisms of action including the fungicide vinclozolin (anti-androgenic), pesticide dichlorodiphenyltrichloroethane (estrogenic), herbicide atrazine (endocrine disruptor at cyclic adenosine monophosphate level), and hydrocarbon mixture jet fuel (JP8) (aryl hydrocarbon receptor disruptor) were used to promote transgenerational disease phenotypes in F3 generation outbred rats. New aliquots of sperm, previously collected and used for DNA methylation analyses, were used in the current study for ncRNA sequencing analyses of nuclear RNA. Significant changes in transgenerational sperm ncRNA were observed for each transgenerational exposure lineage. The majority of ncRNA was small noncoding RNAs including piwi-interacting RNA, tRNA-derived small RNAs, microRNAs, rRNA-derived small RNA, as well as long ncRNAs. Although there was some overlap among the different classes of ncRNA across the different exposures, the majority of differentially expressed ncRNAs were exposure-specific with no overlapping ncRNA between the four different exposure lineages in the transgenerational F3 generation sperm nuclear ncRNAs. The ncRNA chromosomal locations and gene associations were identified for a small number of differential expressed ncRNA. Interestingly, an overlap analysis between the transgenerational sperm DMRs and ncRNA chromosomal locations demonstrated small populations of overlapping ncRNA, but a large population of non-overlapping ncRNAs. Observations suggest that transgenerational sperm ncRNAs have both exposure-specific populations within the different classes of ncRNA, as well as some common populations of ncRNAs among the different exposures. The lack of co-localization of many of the ncRNAs with previously identified transgenerational DMRs suggests a distal integration of the different epigenetic mechanisms. The potential use of ncRNA analyses for transgenerational toxicant exposure assessment appears feasible.

Hatching success rate of sea turtle in the north coast of Pinrang Regency, South Sulawesi

Background: Turtles are endangered marine reptile species due to various factors, including hunting, habitat loss, and predation. Therefore, practical conservation efforts are essential to protect turtle populations. One effective conservation strategy is to transfer turtle eggs to safe semi-natural nests. Methods: This study was conducted in Turtle Village, Pinrang Regency. Leatherback and Green Turtle eggs were collected from natural nests along the coast and transferred to semi-natural nests. Observations were made to measure the hatching success rate of the eggs, and factors such as temperature, incubation period, predators, microorganism development, and changes in egg position were also recorded and analyzed. Finding: The results showed that the hatching success rate of eggs in semi-natural nests reached 80.23%. The highest hatching percentage was 86.36%, and the lowest was 68.33%. Factors that influenced hatching success included temperature and incubation period while hatching failure was caused by predators, microorganism development, and changes in egg position. Conclusion: This study shows that semi-natural nests in Turtle Village have a high hatching success rate with supportive environmental conditions and proper egg transmission. This indicates that conservation efforts through egg transfer to semi-natural nests can effectively increase turtle populations. Novelty/Originality: This study: It contributes to turtle conservation by demonstrating the effectiveness of semi-natural nests in increasing the hatching success rate of Leatherback and Green Turtle eggs. This approach can serve as a model for turtle conservation programs in other areas facing similar challenges.

Pinworm (Enterobius Vermicularis) Infestation: An Updated Review.

Pinworm infestation is an important public health problem worldwide, especially among children 5 to 10 years of age in developing countries with temperate climates. The problem is often overlooked because of its mild or asymptomatic clinical manifestations. The purpose of this article was to familiarize pediatricians with the diagnosis and management of pinworm infestation. A search was conducted in August 2023 in PubMed Clinical Queries using the key terms "Enterobius vermicularis," OR "enterobiasis," OR "pinworm." The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article. Enterobiasis is a cosmopolitan parasitosis caused by Enterobius vermicularis. It affects approximately 30% of children worldwide and up to 60% of children in some developing countries. Predisposing factors include poor socioeconomic conditions, inadequate sanitation, poor personal hygiene, and overcrowding. Children aged 5 to 14 years have shown the highest prevalence of enterobiasis.. Egg transmission is mainly by the fecal-oral route. Approximately 30 to 40% of infested patients do not show any clinical symptoms of the disease. For symptomatic patients, the most common presenting symptom is nocturnal pruritus ani. The diagnosis of E. vermicularis infection is best established by the cellophane tape test. The sensitivity of one single test is around 50%; however, the sensitivity increases to approximately 90% with tests performed on three different mornings. If a worm is visualized in the perianal area or the stool, a pathological examination of the worm will yield a definitive diagnosis. As pinworms and eggs are not usually passed in the stool, examination of the stool is not recommended. The drugs of choice for the treatment of pinworm infestation are mebendazole (100 mg), pyrantel pamoate (11 mg/kg, maximum 1 g), and albendazole (400 mg), all of the above-mentioned drugs are given in a single dose and repeated in two weeks. Mebendazole and albendazole are both adulticidal and ovicidal, whereas pyrantel pamoate is only adulticidal. Given their safety and effectiveness, mebendazole and albendazole are currently the best available drugs for the treatment of pinworm infestation. For pregnant women, pyrantel is preferred to mebendazole and albendazole. Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections because reinfection is common even when effective medication is given. In spite of effective treatment of pinworm infestation, recurrences are common. Recurrences are likely due to repeated cycles of reinfection (particularly, autoinfection) because of the short life span of adult pinworms. Good personal hygiene, such as frequent handwashing, especially after bowel movements and before meals, clipping of fingernails, avoidance of finger-sucking, nail-biting, and scratching in the anogenital area, are important preventive measures. Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections.

Review on Diagnostic Methods of Infectious Coryza in Chickens

The total poultry population in Ethiopia is estimated to be 51.35 million. The Poultry sector is a fastest growing among the animal production activities offers an opportunity to feed the fastest growing human population and provide income resources for poor farmers. There are different diseases which can affect chicken. Among the bacterial diseases, Infectious Coryza (IC) is an acute and contagious respiratory disease of chickens caused by the bacteria, Avibacterium paragallinarum. IC is distributed worldwide and typically transmitted by direct contact, airborne droplets and contamination of drinking water. But Egg transmission does not occur. The initial step in the pathogenesis of infectious coryza is adherence to and colonization of the nasal mucosa. The diagnosis can be based on a history of rapid disease spread, clinical symptoms, and pathological changes caused by IC. Diagnostic methods for IC include direct isolation, the HI test for serovar A and Polymerase Chain Reaction (PCR). Diagnosis of Avibacterium paragallinarum have been proposed as alternatives to conventional serotyping by the Page scheme. The HI test, which is one of the most widely used serological test, is often utilized to detect changes in antibody titers in cases of field infection or vaccination, and is useful for evaluating the prevalence of IC in certain areas. Rapid and accurate detection of respiratory IC has become a challenge because of the involvement of more than one agent with similar clinical signs and lesions, which complicates diagnostic decisions, as well as treatment and control strategies.

Parasite dynamics in untreated horses through one calendar year

BackgroundHorses are host to a plethora of parasites. Knowledge of the seasonality of parasite egg shedding and transmission is important for constructing parasite control programs. However, studies describing these patterns are sparse, and have largely been conducted only in the United Kingdom. This study evaluated strongylid egg shedding patterns and transmission dynamics of Strongylus vulgaris in naturally infected and untreated mares and foals through one calendar year in Kentucky, USA. The study also investigated the existence of a peri-parturient rise (PPR) in strongylid egg counts in foaling mares and collected information about Strongyloides westeri and Parascaris spp. in the foals.MethodsThis study was conducted from January to December 2018. A herd of 18 mares, one stallion, and 14 foals born in 2018 were followed throughout the year. Sera and feces were collected biweekly from all horses, and worm burdens enumerated in 13 foals at necropsy. An S. vulgaris ELISA antibody test was run on all serum samples. Fecal egg counts were determined for all horses, and coproculture and qPCR assay were employed to test for the presence of S. vulgaris in the mature horses. Data were analyzed using the proc glimmix procedure in the SAS 9.4 software program.ResultsWe found a general lack of seasonality in strongylid egg shedding throughout the year among the mature horses, and no PPR was demonstrated. Shedding of S. vulgaris eggs displayed a higher abundance during the spring, but findings were variable and not statistically significant. Anti-S. vulgaris antibody concentrations did not display significant fluctuations in the mature horses, but evidence of passive transfer of antibodies to the foals was demonstrated, and foals assumed their own production of antibodies starting at approximately 20 weeks of age. Overall, colts shed higher numbers of strongylid, ascarid, and S. westeri eggs than fillies.ConclusionsThis study demonstrated a lack of seasonality in strongylid egg shedding for the study population, which is in stark contrast to previous studies conducted elsewhere. This strongly suggests that more studies should be done investigating these patterns under different climatic conditions.Graphical

The life history strategy of a fur seal hookworm in relation to pathogenicity and host health status.

The strategies that parasites use to exploit their hosts can lead to adverse effects on human and animal populations. Here, we describe the life cycle, epidemiology, and consequences of hookworm (Uncinaria sp.) disease in South American fur seals (Arctocephalus australis), and propose that hookworm adaptation to fur seal life history traits has led to maximizing transmission at high levels of parasite-induced anemia and mortality. Fur seal pups acquire hookworms during their first days of life through their mothers' colostrum and most adult hookworms are expelled from the pups' intestine 30–65 days later. This gives hookworms little time to feed and reproduce. However, despite reaching high within-host densities, female hookworms do not decrease egg output, therefore pups with high hookworm burden contribute disproportionately to parasite egg shedding. These heavily infected pups also suffer severe anemia and high levels of hookworm-induced mortality. Alternative strategies to maximize total egg shedding and/or transmission, such as increased environmental survival of larval stages or avoidance of clearance, have not been developed by this hookworm. We propose that fur seal hookworms exploit a live fast-die young life history strategy, which translates to the highest levels of host anemia and mortality recorded among hookworms.

Evaluation of the egg transmission and pathogenicity of Mycoplasma gallisepticum isolates genotyped as ts-11

Live Mycoplasma gallisepticum vaccines are used for the control of respiratory disease, egg production losses and egg transmission associated with M. gallisepticum infection in long-lived poultry. The first field case of apparent increased virulence and vertical transmission of ts-11, a live M. gallisepticum vaccine, has been reported. In that study a M. gallisepticum isolate from the broiler progeny of ts-11-vaccinated breeders was genotyped as ts-11 by sequence analysis of four different genetic targets and Random Amplified Polymorphic DNA and found to be significantly more virulent than ts-11 vaccine. The objective of the current study was to evaluate the rate of egg transmission and pathogenicity of ts-11 vaccine and isolates recovered from ts-11-vaccinated breeders (K6222B) and their broiler progeny (K6216D) which had been genotyped as ts-11. Groups of 28-week-old specific pathogen-free chickens at 87% average weekly egg production were inoculated with sterile broth media (negative controls), ts-11 vaccine, K6222B, K6216D or R strain (positive controls) by eye-drop and aerosol. K6216D transmitted via the egg at an average rate of 4.0% in the third and fourth weeks post-infection, while egg transmission of K6222B and ts-11 vaccine was not detected. M. gallisepticum was isolated from the air sacs, ovaries and oviducts of hens infected with K6216D and K6222B, but not from those infected with ts-11 vaccine. K6216D and K6222B both induced respiratory signs and significantly more tracheal colonization and more severe tracheal and air sac lesions than ts-11 vaccine (P ≤ 0.05). There were no substantial differences in the egg production of ts-11, K6216D and K6222B infected groups. These results provide the first conclusive evidence of transovarian transmission of an isolate genotyped as ts-11 and indicate that isolates genotyed as ts-11 vary in their virulence and ability to transmit via the egg.

Evidence for horizontal and vertical transmission in Campylobacter passage from hen to her progeny.

Campylobacter is an important human pathogen, and consumption of undercooked poultry has been linked to significant human illnesses. To reduce human illness, intervention strategies targeting Campylobacter reduction in poultry are in development. For more than a decade, there has been an ongoing national and international controversy about whether Campylobacter can pass from one generation of poultry to the next via the fertile egg. We recognize that there are numerous sources of Campylobacter entry into flocks of commercial poultry (including egg transmission), yet the environment is often cited as the only source. There has been an abundance of published research globally that refutes this contention, and this article lists and discusses many of them, along with other studies that support environment as the sole or primary source. One must remember that egg passage can mean more than vertical, transovarian transmission. Fecal bacteria, including Campylobacter, can contaminate the shell, shell membranes, and albumen of freshly laid fertile eggs. This contamination is drawn through the shell by temperature differential, aided by the presence of moisture (the "sweating" of the egg); then, when the chick emerges from the egg, it can ingest bacteria such as Campylobacter, become colonized, and spread this contamination to flock mates in the grow house. Improvements in cultural laboratory methods continue to advance our knowledge of the ecology of Campylobacter, and in the not-so-distant future, egg passage will not be a subject continuously debated but will be embraced, thus allowing the development and implementation of more effective intervention strategies.

An insulin-like peptide regulates egg maturation and metabolism in the mosquito Aedes aegypti

Ingestion of vertebrate blood is essential for egg maturation and transmission of disease-causing parasites by female mosquitoes. Prior studies with the yellow fever mosquito, Aedes aegypti, indicated blood feeding stimulates egg production by triggering the release of hormones from medial neurosecretory cells in the mosquito brain. The ability of bovine insulin to stimulate a similar response further suggested this trigger is an endogenous insulin-like peptide (ILP). A. aegypti encodes eight predicted ILPs. Here, we report that synthetic ILP3 dose-dependently stimulated yolk uptake by oocytes and ecdysteroid production by the ovaries at lower concentrations than bovine insulin. ILP3 also exhibited metabolic activity by elevating carbohydrate and lipid storage. Binding studies using ovary membranes indicated that ILP3 had an IC(50) value of 5.9 nM that was poorly competed by bovine insulin. Autoradiography and immunoblotting studies suggested that ILP3 binds the mosquito insulin receptor (MIR), whereas loss-of-function experiments showed that ILP3 activity requires MIR expression. Overall, our results identify ILP3 as a critical regulator of egg production by A. aegypti.

Comparative evaluation of a bivalent killed Salmonella vaccine to prevent egg contamination with Salmonella enterica serovars Enteritidis, Typhimurium, and Gallinarum biovar Pullorum, using 4 different challenge models

We evaluated a newly developed commercial bivalent killed Salmonella vaccine Oilvax SET for its ability to decrease contamination with Salmonella enterica serovars Enteritidis and Typhimurium in layer chickens. In either an oral or intravaginal challenge model, the fecal shedding was decreased in vaccinated hens, but egg contamination was not evaluated due to scarcity of contaminated eggs even in the unvaccinated control groups. In contrast, an intravenous and an intraperitoneal challenge resulted in the relatively high level of egg contamination in unvaccinated chickens, which was significantly reduced in vaccinated chickens. In a second experiment, 2 strains of Salmonella serovar Gallinarum biovar Pullorum, which has the common O9 antigen with SE and transmits vertically into eggs, were used to test the efficacy of the Oilvax SET against egg transmission. Vertical egg transmission by the Pullorum strain was significantly reduced in the vaccinated groups of hens. The Oilvax SET can be a useful tool in the control of Salmonella egg contamination in laying hens.

Schistosome egg production is dependent upon the activities of two developmentally regulated tyrosinases

Egg production is responsible for life cycle progression and host immunopathology during schistosomiasis, with the associated parasite molecules being investigated as potential novel chemotherapeutic targets. Here, we characterize two Schistosoma mansoni products, tyrosinase 1 and tyrosinase 2 (SmTYR1/SmTYR2) and show that their diphenol oxidase enzyme activities are critical for eggshell formation and production. The genes encoding these bifunctional enzymes (monophenol and diphenol oxidases) result from a duplication event that likely occurred before speciation and exist in the parasite's genome as multiple copies, which are linked and localized to chromosomes 4 and W. SmTYR1/SmTYR2 transcription and diphenol oxidase action are developmentally regulated with most enzyme activity localized to the eggshell-producing cells contained within the vitellaria of adult female worms. Importantly, kojic-acid mediated inhibition (IC50=0.5 microM) of SmTYR1/SmTYR2's diphenol oxidase activity during in vitro culture of sexually mature adult worms resulted in a significant decrease in the production of phenotypically normal eggs. Therefore our data suggest that SmTYR1/2 inhibition represents a novel and potentially effective strategy for combating schistosomiasis and furthermore, it may point to new methods for combinatorial control of immunopathology and egg transmission during platyhelminth infection.

Ecological influences on transmission rates of Ascaris suum to pigs on pastures

A study was conducted to determine the distribution and transmission rate of Ascaris suum eggs and Oesophagostomum dentatum larvae in a pasture/pig house facility, which during the preceding summer was contaminated with helminth eggs by infected pigs. In May, four groups of 10 helminth naı̈ve tracer pigs were exposed to fenced sections of the facility for 7 days and necropsied for parasite recovery 9–10 days later (trial 1). The highest rate of A. suum transmission (201 eggs per day) occurred in the pig house (A). On the pasture, egg transmission decreased with the distance from the house: 8 eggs per day in the feeding/dunging area (B); 1 egg per day on the nearest pasture (C); <1 egg per day on the distant pasture (D). Only a few O. dentatum infections were detected, indicating a poor ability of the infective larvae to overwinter. Soil analyses revealed that the highest percentage (5.8%) of embryonated A. suum eggs were in the house (A). Subsequently, the facility was recontaminated with A. suum eggs by infected pigs. A replicate trial 2 was conducted in the following May. A major finding was the complete reversal of egg distribution between the 2 years (trials 1 and 2). In contrast to previous results, the highest rates of transmission (569 and 480 eggs per day) occurred in pasture sections C and D, and the lowest transmission rates (192 and 64 eggs per day) were associated with the feeding/dunging sections and the house (B and A). Soil analyses again supported the tracer pig results, as the pasture sections had the highest concentrations of embryonated eggs. Detailed soil analysis also revealed a non-random, aggregated egg distribution pattern. The different results of the two trials may be due to the seasonal timing of egg deposition and tracer pig exposure. Many eggs deposited during the summer prior to trial 1 may have died rapidly due to high temperatures and dessication, especially when they were not protected by the house, while deposition in the autumn may have favored egg survival through lower temperatures, more moisture, and greater sequestration of eggs in the soil by rain and earthworms. The latter eggs may, however, not have become embryonated until turnout the next year. The results demonstrate that yearly rotations may not be sufficient in the control of parasites with long-lived eggs, such as A. suum, and that a pasture rotation scheme must include all areas, including housing.

Arthropathic and amyloidogenic Enterococcus faecalis infections in brown layers: A study on infection routes

Intravenous, intra-articular and intraperitoneal inoculation of 6-week-old brown-layer pullets with an arthropathic and amyloidogenic strain of Enterococcus faecalis resulted in amyloid arthropathy, while intramuscular, oral and intratracheal inoculation did not. Oral inoculation of 1-day-old chickens did not cause any pathology. However, intramuscular inoculation with 106 colony forming units resulted in severe growth retardation and arthritis in 60% of the birds, and amyloid arthropathy in approximately 40%. In egg transmission studies, neither egg dipping nor inoculation of the air chamber with E. faecalis reproduced the condition, although a few chicks became septicaemic. Yolk sac inoculation of 6-day-old embryos caused embryonic death within 2 days. In contrast, egg albumen inoculation with E. faecalis led to arthritis in one of six of the progeny, indicating the possibility that vertical transmission of E. faecalis by the oviductal route could lead to arthritis. The presence of antibodies to E. faecalis was confirmed by enzyme-linked immunosorbent assay in 14/15 of experimental birds that had developed arthritis.

Egg transmission of avian reoviruses in chickens: Comparison of a trypsin‐sensitive and a trypsin‐resistant strain

Two groups of commercial Light Sussex hens with no cultural evidence of reovirus infection and very low titres of neutralising antibodies were mated with cockerels from 17 weeks of age. At 27 weeks of age the birds were separated into three groups, and were inoculated intranasally and intravenously with avian reovirus strain R2 which is resistant to trypsin, with strain TR1 which is sensitive to the enzyme or sham-inoculated. Of the eggs laid by the hens infected with strain R2, 13/29 infertile eggs and embryos which fails to hatch were positive for virus, as were 6/70 hatched chicks. Despite this, virus was never isolated from cloacal swabs from the hens. Virus-infected eggs were laid between days 5 to 17 post inoculation (p.i.). Virus was isolated from the liver of all six R2 virus-positive chicks, from the hock joint of four and from the intestine of three. In contrast, for the group infected with the trypsin-sensitive virus TR1, of 120 eggs laid in the 5-week period, virus was isolated once only, from a chick hatched from an egg laid 7 days p.i. This infected chick was one of 83 which hatched and virus was found only in the joint. In a further experiment, two groups of mature SPF hens were inoculated with the reoviruses as above. Cloacal swabs and tissue examination showed greater virus excretion and tissue distribution of R2 than TR1. These results helped to explain the much higher egg transmission rate of R2 than TR1. However, the rate of vertical transmission of chicken reoviruses in nature, where the infectious dose would normally be lower than given here, is likely to be low.

Evaluation of Enrofloxacin against Egg Transmission of Mycoplasma gallisepticum

Five groups of 20 commercial leghorn hens near peak production were challenged with Mycoplasma gallisepticum, and medicated with enrofloxacin in the drinking water at 7-11, 21-25, or 7-11 and 21-25 days postchallenge (PC), a combination of lincomycin/spectinomycin at 7-11 and 21-25 days PC, or left as untreated controls. Egg production records were maintained, and all eggs produced during the 63 days following challenge were incubated for 18 days and then cultured for M. gallisepticum. All groups experienced marked egg production drops beginning about 1 week PC; production returned to near normal levels after approximately 3 weeks. Under the conditions of this study water medication did not prevent egg production losses, probably because of the delay in the onset of medication, but medication may have resulted in a more rapid recovery of egg production. Enrofloxacin was highly effective in reducing the level of egg transmission of M. gallisepticum, although a small number of eggs (0-0.3%) in the treated groups were culture positive after medication was begun. Only 1 of 2463 live embryos was culture positive after the onset of treatment. In the unmedicated control group, 12.8% of all eggs were culture positive. Lincomycin/spectinomycin also reduced egg transmission (3.4% of eggs were culture positive after treatment was initiated), but not as effectively as enrofloxacin. Most of the egg transmission occurred before the medication could have had an effect. Both enrofloxacin and lincomycin/spectinomycin reduced the number of dead-in-shell embryos.

Isolation of Chlamydia psittaci from a chicken egg: evidence of egg transmission.

Isolation of Chlamydia psittaci from a chicken egg: evidence of egg transmission.

ExperimentalSalmonella enteritidisphage type 4 infection and egg transmission in Japanese quails

Japanese quails were inoculated orally with 1 x 10(10) colony-forming units of Salmonella enteritidis phage type 4 isolated from chicks to obtain information concerning S. enteritidis infection and egg transmission. The inoculation resulted in a bacteraemic infection with seeding of the liver, spleen, intestine, peritoneum, ovule, ovary and oviduct. Some infected birds showed diarrhoea, ruffled feathers, depression, loss of appetite and death. However, most infected birds remained clinically normal with normal egg production. Salmonella enteritidis was isolated from the albumen of 7, yolk of 15, shell of 13, and shell membrane of 15 of 164 eggs. The experiment suggests that S. enteritidis phage type 4 is invasive for Japanese quails and the infected eggs laid by S. enteritidis infected quails are probably the result of transovarian infection.

Pathogenesis of Salmonella enteritidis Infection in Laying Chickens. I. Studies on Egg Transmission, Clinical Signs, Fecal Shedding, and Serologic Responses

Laying hens were inoculated orally, intracloacally (IC), or intravenously (IV) with Salmonella enteritidis phage type 8 isolates from a human (E700-87) eggs (Y-8P2), or the ovary of a hen (27A). Oral or IV inoculation of 2 x 10(8) to 4 x 10(8) colony-forming units (CFU) of E700-87 caused depression, anorexia, reduced egg production, diarrhea, and some mortality. Lower doses resulted in milder clinical signs. S. enteritidis was cultured from the shells of a few eggs but not from egg contents. Fecal shedding persisted for up to 6 weeks in some birds. Isolate Y-8P2 (10(6) CFU) also caused anorexia, diarrhea, and a drop in egg production. Hens inoculated orally or IC were less severely affected than those inoculated IV. Fecal shedding was intermittent and lasted up to 18 days. Eggshells from the IC-inoculated birds had the highest rate of contamination, and S. enteritidis was isolated from the albumen of 11 and yolk of three of 726 eggs. Oral inoculation of 10(6) CFU of isolate 27A resulted in a bacteremic infection with seeding of the liver, spleen, peritoneum, ovule, and oviduct. However, the birds remained clinically normal with normal egg production. S. enteritidis was cultured from the yolk and albumen of a small number of eggs until 11 days postinfection. Antigen prepared from S. enteritidis detected antibody in more sera than did commercially available S. pullorum antigen in agglutination tests.

Egg transmission after infection of hens with Salmonella enteritidis phage type 4.

Egg transmission after infection of hens with Salmonella enteritidis phage type 4.

Mycoplasma Iowae:Field and laboratory studies to evaluate egg transmission in Turkeys

In order to study the egg transmission of Mycoplasma iowae in turkeys, two experiments are undertaken. Experiment 1 was a field trial designed to investigate egg transmission in naturally infected turkeys: commercial hens were inseminated with semen from naturally infected toms. Mycoplasma iowae was regularly cultured from dead-in-shell embryos, pips and culls but not from healthy poults. Egg transmission occurred from the second up to the tenth week of production. Experiment 2 was a laboratory study conducted to observe persistence and egg transmission of M. iowae in experimentally infected turkeys. Specific pathogen free (SPF) hens were inoculated either intracheally or intravaginally. They were then artificially inseminated with semen from SPF toms. Very little egg transmission was observed. The cultures from tracheal or vaginal swabs of the inoculated hens showed a limited invasive ability of M. iowae in the adult bird. The humoral immune response as detected by the metabolism inhibition test, was very poor. The observations made in these two experiments show the importance of venereal spread of M. iowae, especially under artificial insemination. Consequently, the need for monitoring toms is obvious.