Perdas devido à natimortalidade, mumificação fetal, abortamentos e morte embrionária são responsáveis por uma considerável queda no desempenho da indústria suinícola no Brasil e no mundo. Dentre os agentes mais freqüentemente descritos como causadores de falhas reprodutivas em suínos pode-se citar o Parvovírus suíno, Leptospira spp. O diagnóstico das causas infecciosas de mortalidade embrionária e fetal torna-se muitas vezes inviável pelo estado de autólise do material ou dificuldades inerentes às características de crescimento do vírus ou bactéria envolvido. O presente estudo teve por objetivo avaliar os resultados obtidos no período de oito anos de detecção de Parvovirus suíno e Leptospira spp. em falhas reprodutivas e discutir alguns aspectos relativos ao diagnóstico destas infecções. Foram avaliados 1901 fetos, sendo coletadas de cada animal, uma amostra de pool de órgãos e uma de conteúdo gástrico, perfazendo um total de 3642 análises. Observou-se uma freqüência de 27,6% dos fetos positivos para Parvovirus suíno, 19,8% positivos para Leptospira spp e 1,1% positivos para os dois agentes em associação. Dentre as 339 granjas avaliadas em oito Estados Brasileiros, 48,5% foram positivas para um ou ambos agentes pesquisados. Avaliou-se a freqüência de fetos positivos em casos de abortamento, natimortalidade e mumificação fetal e comparou-se a eficiência da pesquisa dos agentes em amostras de órgãos, conteúdo gástrico e em ambos. Os resultados obtidos indicam a grande importância destes agentes infecciosos nos quadros de falha reprodutiva em granjas de suínos no Brasil, apesar da ampla utilização de vacinas contra os mesmos. . / Losses due to stillbirths, mummification, embryonic death and abortions account for a considerable drop in performance of the pig industry in Brazil and the world. Among the agents most frequently described as causes of reproductive failure in pigs may be mentioned the swine parvovirus, Leptospira spp. The diagnosis of infectious causes of fetal and embryonic mortality it is often impossible for the state of autolysis of the material or the difficulties inherent growth characteristics of the virus or bacteria involved. Present study has the goal evaluate the results obtained in eight year period of Parvovirus and Leptospira spp. detection in reproductive failure and discuss some aspects related to diagnosis of these infections. A total of 1901 fetuses were examined, and from each animal a sample of different tissues and a sample of gastric contents were collected, representing 3642 analysis. A frequency of 27.6% of Parvovirus positive fetuses were observed, followed by 19.8% of Leptospira spp. positive fetuses, and 1.1% positive to both agents. Among 339 swine herds evaluated from eight Brazilian States, 48,5% were positive to one or both infectious agents. The frequency of positive fetuses in abortion, stillbirths and mummification, and the efficiency of virus and bacterial detection from organs and gastric contents were compared. The results obtained indicate the high importance of these infectious agents in reproductive failure in Brazilian swine herds, beside the large utilization of commercial vaccines against then.

Perdas devido à natimortalidade, mumificação fetal, abortamentos e morte embrionária são responsáveis por uma considerável queda no desempenho da indústria suinícola no Brasil e no mundo. Dentre os agentes mais freqüentemente descritos como causadores de falhas reprodutivas em suínos pode-se citar o Parvovírus suíno, Leptospira spp. O diagnóstico das causas infecciosas de mortalidade embrionária e fetal torna-se muitas vezes inviável pelo estado de autólise do material ou dificuldades inerentes às características de crescimento do vírus ou bactéria envolvido. O presente estudo teve por objetivo avaliar os resultados obtidos no período de oito anos de detecção de Parvovirus suíno e Leptospira spp. em falhas reprodutivas e discutir alguns aspectos relativos ao diagnóstico destas infecções. Foram avaliados 1901 fetos, sendo coletadas de cada animal, uma amostra de pool de órgãos e uma de conteúdo gástrico, perfazendo um total de 3642 análises. Observou-se uma freqüência de 27,6% dos fetos positivos para Parvovirus suíno, 19,8% positivos para Leptospira spp e 1,1% positivos para os dois agentes em associação. Dentre as 339 granjas avaliadas em oito Estados Brasileiros, 48,5% foram positivas para um ou ambos agentes pesquisados. Avaliou-se a freqüência de fetos positivos em casos de abortamento, natimortalidade e mumificação fetal e comparou-se a eficiência da pesquisa dos agentes em amostras de órgãos, conteúdo gástrico e em ambos. Os resultados obtidos indicam a grande importância destes agentes infecciosos nos quadros de falha reprodutiva em granjas de suínos no Brasil, apesar da ampla utilização de vacinas contra os mesmos. . / Losses due to stillbirths, mummification, embryonic death and abortions account for a considerable drop in performance of the pig industry in Brazil and the world. Among the agents most frequently described as causes of reproductive failure in pigs may be mentioned the swine parvovirus, Leptospira spp. The diagnosis of infectious causes of fetal and embryonic mortality it is often impossible for the state of autolysis of the material or the difficulties inherent growth characteristics of the virus or bacteria involved. Present study has the goal evaluate the results obtained in eight year period of Parvovirus and Leptospira spp. detection in reproductive failure and discuss some aspects related to diagnosis of these infections. A total of 1901 fetuses were examined, and from each animal a sample of different tissues and a sample of gastric contents were collected, representing 3642 analysis. A frequency of 27.6% of Parvovirus positive fetuses were observed, followed by 19.8% of Leptospira spp. positive fetuses, and 1.1% positive to both agents. Among 339 swine herds evaluated from eight Brazilian States, 48,5% were positive to one or both infectious agents. The frequency of positive fetuses in abortion, stillbirths and mummification, and the efficiency of virus and bacterial detection from organs and gastric contents were compared. The results obtained indicate the high importance of these infectious agents in reproductive failure in Brazilian swine herds, beside the large utilization of commercial vaccines against then.

Isolates of Monilinia fructicola (Wint.) Honey obtained from stone fruit orchards in Hawkes Bay, North Island and from Californian fruit exported to New Zealand, were tested for resistance to methyl benzimidazole carbamate (MBC). Resistant isolates from the North Island had EC₅₀ values of >30,000, and most isolates from the imported fruit had of values approximately 1.5 mg a.i./l carbendazim. Sensitive isolates failed to grow on 1 mg a.i./l carbendazim. A detached peach shoot system was used in controlled conditions for estimation of values for incubation period, latent period and rate of spore production on flowers (cv Glohaven). The same variables and the rate of colonisation of host tissue were measured on fruit (cv Fantasia) in controlled conditions. An inoculum density of 1x10⁴ spore/flower or fruit greatly increased fitness in vivo compared to an inoculum density of 1x10² spore/flower (fruit). Isolates varied considerably, but there was no consistent relationship between the degrees of resistance and fitness. This was in contrast to earlier studies with dicarboximide resistant strains of M. fructicola. The survival in the field of 10 isolates resistant or sensitive to MBC or dicarboximide fungicides on twig cankers and mummified fruit was compared. The ability to produce conidia on twig cankers inoculated in late spring 1989 was maintained by all sensitive and MBC resistant isolates for at least 1 year. The production of conidia on mummified fruit inoculated in February 1990 decreased after 2-3 months in the field but some conidia were still produced on all fruit in the following spring. Dicarboximide resistant isolates produced less conidia than either the MBC resistant and the sensitive isolates. The pathogenicity and fitness of all isolates were similar to the original values after survival for 1 year. A technique was developed to produce apothecia reliably from inoculated peach (cv Black Boy) and nectarine (cv Fantasia) fruit in controlled conditions in the laboratory. The fruit were inoculated with resistant or sensitive isolates, or combinations, and were incubated for 8 weeks at 25°C (±1°C) with 12 hours photoperiod of fluorescent light (Sylvania 2x65 W, daylight) to produce mummified fruit. The fruit were then buried in moist autoclaved peat moss for 10 weeks at 25°C (±1°C) in the dark to form stromata. These fruit were then hydrated with running tap-water (total hardness (CaCO₃) = 47 g/m³ and conductivity at 20°C = 12.7 mS/m) for 72 hours. The hydrated mummified fruit were placed in moist peat moss and were incubated for 13-14 weeks at 8°C (±0.5°C) in the dark. At the end of this period, stipe initials were visible. Differentiation of stipe initials into mature apothecia occurred within 15-20 days after transfer to 12°C (±2 °C) with a 12 hour photoperiod of fluorescent and incandescent light. All isolates produced apothecia when treated in this way. A technique for isolation of ascospore sets in linear arrangement was developed for tetrad analysis of the inheritance of resistance. At least 3 hours of fluorescent and incandescent light at 12°C (±2°C) was essential to allow ascospore ejection from individual asci taken from apothecia previously maintained in a 12 hour photoperiod at 12°C (±1°C). A water film on the surface of water agar was necessary to hold a set of ejected ascospores in linear sequence. Single ascospores were obtained in sequence with the aid of a micromanipulator. Genetic analysis of MBC resistant isolates was carried out on ascospores derived from apothecia produced in the laboratory. Analysis of ascospore sets in linear arrangement and ascospore populations indicated that resistance to >30,000 mg a.i./l carbendazim (high-resistant) is governed by a single major gene and is affected by gene conversion mechanisms. Crossing over was frequent, suggesting that recombination of resistance with other characters, such as pathogenicity and fitness, may occur readily. The segregation ratio (1:1) from most resistant isolates revealed that heterokaryons containing both resistant and sensitive alleles were common in resistant populations and that resistance is dominant. Allozyme analysis of ascospore progeny through electrophoresis revealed a narrow genetic base of M. fructicola in New Zealand. The technique for reliable apothecial production in controlled conditions developed in this study provided an important step for the determination of the biology of M. fructicola strains resistant to MBC fungicides, and the complexity of its life cycle. Genetic heterogeneity in field populations can be conserved in one isolate through heterokaryosis, thus providing for adaptability of the pathogen to the changing environmental conditions. Knowledge on genetic variability, overwintering ability, pathogenicity and fitness factors may be useful for future management strategies of stone fruit brown rot. Special emphasis should be made in particular to prevent primary infection on blossoms, which would delay the establishment of recombinant strains of M. fructicola and the onset of brown rot epidemics.