Fungal Pathogens of Cacao in Puerto Rico.

Cacao production is a rapidly expanding industry in Puerto Rico, with new farmers planting ~20,000 trees in the past few years. To determine the etiology and extent of diseases affecting cacao in Puerto Rico, a survey was performed at eight sites around the island. Pod rot and/or branch dieback were observed at all sites. Most organisms isolated from symptomatic pod and stem samples were identified as Diaporthe spp. (48%) and Lasiodiplodia spp. (25%) based on sequences of the internal transcribed spacer and large subunit regions. Within these genera, Diaporthe tulliensis and Lasiodiplodia theobromae were the most prevalent species and were used in inoculation studies to determine their relative virulence on pods and stems. Phytophthora palmivora served as a positive control due to its well-established pathogenicity in all tissues. On pods, L. theobromae and P. palmivora caused significantly larger lesions (6.1 and 5.9 cm, respectively) than D. tulliensis (2.7 cm) four days post-inoculation. All three species caused disease on stems, with no differences found among species. Although P. palmivora was thought to be the primary pathogen affecting cacao in Puerto Rico, this study identifies L. theobromae and D. tulliensis as the common pathogens on the island. This improved understanding will help scientists and farmers control disease by selecting fungicides effective against both oomycetes and fungi.

Phyllosphere microbial diversity and specific taxa mediate within-cultivar resistance to Phytophthora palmivora in cacao.

The oomycete pathogen Phytophthora palmivora, which causes black pod rot (BPR) on cacao (Theobroma cacao L.), is responsible for devastating yield losses worldwide. Genetic variation in resistance to Phytophthora spp. is well documented among cacao cultivars, but variation has also been observed in the incidence of BPR even among trees of the same cultivar. In light of evidence that the naturally occurring phyllosphere microbiome can influence foliar disease resistance in other host-pathogen systems, it was hypothesized that differences in the phyllosphere microbiome between two field accessions of the cultivar Gainesville II 164 could be responsible for their contrasting resistance to P. palmivora. Bacterial alpha diversity was higher but fungal alpha diversity was lower in the more resistant accession MITC-331, and the accessions harbored phyllosphere microbiomes with distinct community compositions. Six bacterial and 82 fungal amplicon sequence variants (ASVs) differed in relative abundance between MITC-333 and MITC-331, including bacterial putative biocontrol agents and a high proportion of fungal pathogens, and nine fungal ASVs were correlated with increased lesion development. The roles of contrasting light availability and host mineral nutrition, particularly potassium, are also discussed. Results of this preliminary study can be used to guide research into microbiome-informed integrated pest management strategies effective against Phytophthora spp. in cacao. IMPORTANCE Up to 40% of the world's cacao is lost each year to diseases, the most devastating of which is black pod rot, caused by Phytophthora palmivora. Though disease resistance is often attributed to cacao genotypes (i.e., disease-resistant rootstocks), this study highlights the role of the microbiome in contributing to differences in resistance even among accessions of the same cacao cultivar. Future studies of plant-pathogen interactions may need to account for variation in the host microbiome, and optimizing the cacao phyllosphere microbiome could be a promising new direction for P. palmivora resistance research.

Mealybug (Hemiptera: Pseudococcidae) Species Associated with Cacao Mild Mosaic Virus and Evidence of Virus Acquisition.

Theobroma cacao is affected by viruses on every continent where the crop is cultivated, with the most well-known ones belonging to the Badnavirus genus. One of these, cacao mild mosaic virus (CaMMV), is present in the Americas, and is transmitted by several species of Pseudococcidae (mealybugs). To determine which species are associated with virus-affected cacao plants in North America, and to assess their potential as vectors, mealybugs (n = 166) were collected from infected trees in Florida, and identified using COI, ITS2, and 28S markers. The species present were Pseudococcus jackbeardsleyi (38%; n = 63), Maconellicoccus hirsutus (34.3%; n = 57), Pseudococcus comstocki (15.7%; n = 26), and Ferrisia virgata (12%; n = 20). Virus acquisition was assessed by testing mealybug DNA (0.8 ng) using a nested PCR that amplified a 500 bp fragment of the movement protein-coat protein region of CaMMV. Virus sequences were obtained from 34.6 to 43.1% of the insects tested; however, acquisition did not differ among species, X2 (3, N = 166) = 0.56, p < 0.91. This study identified two new mealybug species, P. jackbeardsleyi and M. hirsutus, as potential vectors of CaMMV. This information is essential for understanding the infection cycle of CaMMV and developing effective management strategies.

Complete genome sequences of three newly discovered cacao mild mosaic virus isolates from Theobroma cacao L. in Brazil and Puerto Rico and evidence for recombination.

To analyze the DNA virome associated with cacao (Theobroma cacao L.) trees showing virus-like symptoms in Brazil (BR) and Puerto Rico (PR) during 2018-2019, total DNA was isolated from symptomatic leaves and subjected to high-throughput Illumina sequencing. The assembled complete badnaviral genome sequences were verified by PCR amplification, cloning, and DNA sequencing. Based on pairwise distances and phylogenetic analysis, three badnaviral genomes were identified, and these viruses were found to be isolates of the previously described cacao mild mosaic virus (CaMMV). The three genomes were 7,520, 7,524, and 7,514 bp in size for the isolates CaMMV-BR321, CaMMV-BR322, and CaMMV-PR3, respectively. Each genome contained four predicted open reading frames: ORFs 1-3 and ORFY. The CaMMV-PR3 isolate was identified as a probable recombinant, with a CaMMV-BR-like virus as the major parent.

Phytophthora theobromicola sp. nov.: A New Species Causing Black Pod Disease on Cacao in Brazil.

Black pod disease, caused by Phytophthora species, is among the main limiting factors of cacao (Theobroma cacao L.) production. High incidence levels of black pod disease have been reported in Brazil, being induced by Phytophthora capsici, Phytophthora citrophthora, Phytophthora heveae, and Phytophthora palmivora. To assess the diversity of Phytophthora species affecting cacao in Brazil, 40 new isolates were obtained from cacao pods exhibiting symptoms of black pod disease collected in different smallholder farms in 2017. Further, ten cacao-infecting isolates morphologically identified as P. citrophthora and P. palmivora were molecularly characterized. The genomic regions beta-tubulin, elongation factor 1 alpha, heat shock protein 90, and internal transcribed spacer, and the mitochondrially encoded cytochrome c oxidase I and II genes were PCR-amplified and Sanger-sequenced from the cacao-infecting Phytophthora isolates. The morphological characterization and evaluation of the mycelial growth rates for the Phytophthora isolates were performed in vitro. Based on the molecular analysis and morphological comparisons, 19 isolates were identified as P. palmivora (clade 4). Interestingly, 31 isolates grouped together in the phylogenetic tree and were placed apart from previously known species in Phytophthora clade 2. Therefore, these isolates are considered as a new species herein referred to as Phytophthora theobromicola sp. nov., which produced papillate, semipapillate, and persistent sporangia on simple sporangiophores. The P. palmivora isolates were identified as A1 mating type by pairing each isolate with known A1 and A2 tester strains of P. capsici, but no oogonia/antheridia were observed when P. theobromicola was paired with the different tester strains. The P. theobromicola and P. citrophthora isolates showed higher mycelial growth rates, when compared to P. palmivora, on different media at 10, 15, and 20°C, but similar values were observed when grown on clarified CA media at 25 and 30°C. The pathogenicity tests carried out on pods of four cacao clones (CCN51, PS1319, Cepec2004, and CP49) showed significant variability among the isolates of both Phytophthora species, with P. theobromicola inducing higher rates of necrotic lesion expansion, when compared to P. palmivora. Here, two Phytophthora species were found associated with black pod disease in the state of Bahia, Brazil, and the previously undescribed P. theobromicola seems to be prevalent in field conditions. This is the first report of P. theobromicola on T. cacao. Also, these findings are crucial to improve the disease control strategies, and for the development of cacao materials genetically resistant to Phytophthora.

Independent Whole-Genome Duplications Define the Architecture of the Genomes of the Devastating West African Cacao Black Pod Pathogen Phytophthora megakarya and Its Close Relative Phytophthora palmivora.

Phytophthora megakarya and P. palmivora are oomycete pathogens that cause black pod rot of cacao (Theobroma cacao), the most economically important disease on cacao globally. While P. palmivora is a cosmopolitan pathogen, P. megakarya, which is more aggressive on cacao than P. palmivora, has been reported only in West and Central Africa where it has been spreading and devastating cacao farms since the 1950s. In this study, we reconstructed the complete diploid genomes of multiple isolates of both species using single-molecule real-time sequencing. Thirty-one additional genotypes were sequenced to analyze inter- and intra-species genomic diversity. The P. megakarya genome is exceptionally large (222 Mbp) and nearly twice the size of P. palmivora (135 Mbp) and most known Phytophthora species (∼100 Mbp on average). Previous reports pointed toward a whole-genome duplication (WGD) in P. palmivora In this study, we demonstrate that both species underwent independent and relatively recent WGD events. In P. megakarya we identified a unique combination of WGD and large-scale transposable element driven genome expansion, which places this genome in the upper range of Phytophthora genome sizes, as well as effector pools with 1,382 predicted RxLR effectors. Finally, this study provides evidence of adaptive evolution of effectors like RxLRs and Crinklers, and discusses the implications of effector expansion and diversification.

Genome and transcriptome analysis of the latent pathogen Lasiodiplodia theobromae, an emerging threat to the cacao industry.

Lasiodiplodia theobromae (Pat.) Griffon & Maubl., a member of the family Botryosphaeriaceae, is becoming a significant threat to crops and woody plants in many parts of the world, including the major cacao growing areas. While attempting to isolate Ceratobasidium theobromae, a causal agent of vascular streak dieback (VSD), from symptomatic cacao stems, 74% of isolated fungi were Lasiodiplodia spp. Sequence-based identification of 52 putative isolates of L. theobromae indicated that diverse species of Lasiodiplodia were associated with cacao in the studied areas, and the isolates showed variation in aggressiveness when assayed using cacao leaf discs. The present study reports a 43.75 Mb de novo assembled genome of an isolate of L. theobromae from cacao. Ab initio gene prediction generated 13 061 protein-coding genes, of which 2862 are unique to L. theobromae, when compared with other closely related Botryosphaeriaceae. Transcriptome analysis revealed that 11 860 predicted genes were transcriptionally active and 1255 were more highly expressed in planta compared with cultured mycelia. The predicted genes differentially expressed during infection were mainly those involved in carbohydrate, pectin, and lignin catabolism, cytochrome P450, necrosis-inducing proteins, and putative effectors. These findings significantly expand our knowledge of the genome of L. theobromae and the genes involved in virulence and pathogenicity.

Rapid Molecular Identification of Scolytinae (Coleoptera: Curculionidae).

Routine identification of bark and ambrosia beetles is done using morphology. For people lacking the necessary taxonomic knowledge, proper identification of a novel specimen can be challenging and time consuming. This study compares the usefulness of four genetic markers (28S, EF-1a, ITS2, and COI) and five primer pairs (D2F1/D3R2, eflafor1/eflarev1, ets149/efa754, ITS2F/ITS2R, and LCO1490/HCO2198) to identify Scolytinae beetles, and outlines a molecular identification strategy, with results possible in two days. Markers COI and EF-1a were selected based on the ability of the respective primers to amplify DNA from multiple genera (Coptoborus, Xyleborus, Hypothenemus, Theoborus, and Araptus) and the ability of the resulting sequences to provide accurate and unambiguous matches in GenBank. BLASTn analysis of EF-1a sequences (both primer pairs) correctly identified four out of the five genera and COI sequences identified at least one sample of every genus tested and was the only primer pair to correctly identify Araptus specimens. Further, 28S sequences successfully identified Coptoborus, Xyleborus, and Theoborus but not Hypothenemus or Araptus. The low number of EF-1a (1), 28S (7), and ITS2 (0) sequences from Araptus individuals present in GenBank compared with COI (137) is likely the reason that only the latter marker was capable of identifying members of this genus. ITS2 sequences were insufficient to identify any of the samples tested. This study also determined the minimum quantity of DNA that could be used for molecular identification. Primers D2F1 and D3R2, which had the highest rate of amplification in all genera tested, could yield an informative sequence with as little as 0.00048 ng of DNA, however, at least 0.0024 ng was needed for reliable amplification.

Chocolate Under Threat from Old and New Cacao Diseases.

Theobroma cacao, the source of chocolate, is affected by destructive diseases wherever it is grown. Some diseases are endemic; however, as cacao was disseminated from the Amazon rain forest to new cultivation sites it encountered new pathogens. Two well-established diseases cause the greatest losses: black pod rot, caused by several species of Phytophthora, and witches' broom of cacao, caused by Moniliophthora perniciosa. Phytophthora megakarya causes the severest damage in the main cacao producing countries in West Africa, while P. palmivora causes significant losses globally. M. perniciosa is related to a sister basidiomycete species, M. roreri which causes frosty pod rot. These Moniliophthora species only occur in South and Central America, where they have significantly limited production since the beginnings of cacao cultivation. The basidiomycete Ceratobasidium theobromae causing vascular-streak dieback occurs only in South-East Asia and remains poorly understood. Cacao swollen shoot disease caused by Cacao swollen shoot virus is rapidly spreading in West Africa. This review presents contemporary research on the biology, taxonomy and genomics of what are often new-encounter pathogens, as well as the management of the diseases they cause.

Mycobacterium smegmatis proteoliposome induce protection in a murine progressive pulmonary tuberculosis model.

Tuberculosis (TB) remains an important cause of mortality and morbidity. The TB vaccine, BCG, is not fully protective against the adult form of the disease and is unable to prevent its transmission although it is still useful against severe childhood TB. Hence, the search for new vaccines is of great interest. In a previous study, we have shown that proteoliposomes obtained from Mycobacterium smegmatis (PLMs) induced cross reactive humoral and cellular response against Mycobacterium tuberculosis (Mtb) antigens. With the objective to evaluate the protective capability of PLMs, a murine model of progressive pulmonary TB was used. Animals immunized with PLMs with and without alum (PLMs/PLMsAL respectively) showed protection compared to non-immunized animals. Mice immunized with PLMsAL induced similar protection as that of BCG. Animals immunized with BCG, PLMs and PLMsAL showed a significant decrease in tissue damage (percentage of pneumonic area/lung) compared to non-immunized animals, with a more prominent effect in BCG vaccinated mice. The protective effect of the administration of PLMs in mice supports its future evaluation as experimental vaccine candidate against Mtb.

Protective capacity of proteoliposomes from Mycobacterium bovis BCG in a mouse model of tuberculosis.

Tuberculosis (TB) is one of the most important causes of mortality and morbidity due to infectious diseases. BCG, the vaccine in use, is not fully protective against TB. In a previous study, we have shown that proteoliposomes (outer membrane extracts), obtained from BCG (PLBCG) were able to induce humoral immune responses against Mycobacterium tuberculosis (Mtb) antigens. With the objective to evaluate the protective capability of PLBCG alone or as a booster with BCG, a murine model of progressive pulmonary TB was used. Animals immunized with PLBCG adjuvanted with alum (PLBCG-Al) showed similar protection to that conferred by BCG. The group immunized with PLBCG-Al as a booster to BCG gave superior protection than BCG as evidenced by a reduction of bacterial load in lungs 2 months after infection with Mtb. Animals immunized with BCG, PLBCG-Al and this formulation as a booster of BCG, showed a significant decrease of tissue damage (percentage of pneumonic area/lung) compared with non-immunized animals. These results demonstrate that immunization with PLBCG-Al alone or as a booster to BCG induce appropriate protection against challenge with Mtb in mice and support the future evaluation of PLBCG as a promising vaccine candidate against Mtb.

Protective effect of a lipid-based preparation from Mycobacterium smegmatis in a murine model of progressive pulmonary tuberculosis.

A more effective vaccine against tuberculosis (TB) is urgently needed. Based on its high genetic homology with Mycobacterium tuberculosis (Mtb), the nonpathogenic mycobacteria, Mycobacterium smegmatis (Ms), could be an attractive source of potential antigens to be included in such a vaccine. We evaluated the capability of lipid-based preparations obtained from Ms to provide a protective response in Balb/c mice after challenge with Mtb H37Rv strain. The intratracheal model of progressive pulmonary TB was used to assess the level of protection in terms of bacterial load as well as the pathological changes in the lungs of immunized Balb/c mice following challenge with Mtb. Mice immunized with the lipid-based preparation from Ms either adjuvanted with Alum (LMs-AL) or nonadjuvanted (LMs) showed significant reductions in bacterial load (P < 0.01) compared to the negative control group (animals immunized with phosphate buffered saline (PBS)). Both lipid formulations showed the same level of protection as Bacille Calmette and Guerin (BCG). Regarding the pathologic changes in the lungs, mice immunized with both lipid formulations showed less pneumonic area when compared with the PBS group (P < 0.01) and showed similar results compared with the BCG group. These findings suggest the potential of LMs as a promising vaccine candidate against TB.

Passive administration of purified secretory IgA from human colostrum induces protection against Mycobacterium tuberculosis in a murine model of progressive pulmonary infection.

BACKGROUND: Immunoglobulin A is the most abundant isotype in secretions from mucosal surfaces of the gastrointestinal, respiratory and genitourinary tracts and in external secretions such as colostrum, breast milk, tears and saliva. The high concentration of human secretory IgA (hsIgA) in human colostrum strongly suggests that it should play an important role in the passive immune protection against gastrointestinal and respiratory infections. MATERIALS AND METHODS: Human secretory IgA was purified from colostrum. The reactivity of hsIgA against mycobacterial antigens and its protective capacity against mycobacterial infection was evaluated. RESULTS: The passive administration of hsIgA reduces the pneumonic area before challenge with M. tuberculosis. The intratracheal administration of M. tuberculosis preincubated with hsIgA to mice greatly reduced the bacterial load in the lungs and diminished lung tissue injury. CONCLUSIONS: HsIgA purified from colostrum protects against M. tuberculosis infection in an experimental mouse model.

Immunogenicity and cross-reactivity against Mycobacterium tuberculosis of proteoliposomes derived from Mycobacterium bovis BCG.

The only currently available vaccine against tuberculosis (TB) is Mycobacterium bovis Bacille Calmette-Guerin (BCG), which has inconsistent efficacy to protect against the disease in adults. M. tuberculosis (MTB) cell wall components have been implicated in the pathogenicity of TB and therefore have been a prime target for the identification and characterization of cell wall proteins with potential application in vaccine development. In this regard, proteoliposomes (PLs) derived from mycobacteria containing lipids and cell wall proteins could be potential vaccine candidates against TB. In the present study PLs derived from BCG were prepared. These homogeneous population of spherical microparticles was then immunized into Balb/c mice. Sera of immunized animals showed high IgG response and strong cross-reactivity against different MTB antigens.These results showed that BCG PLs could be potential vaccine candidates against TB.

Proteoliposomes from Mycobacterium smegmatis induce immune cross-reactivity against Mycobacterium tuberculosis antigens in mice.

Proteoliposomes (PL) obtained from Mycobacterium smegmatis (Ms) were evaluated for their capacity to elicit cross-reactive responses against Mycobacterium tuberculosis (Mtb) antigens in BALB/c mice. Animals immunized with PL adjuvanted with alum (PL-AL) or Freund's Incomplete Adjuvant (PL-IFA) showed significant IgG responses against the PL as well as total Ms lipids. Both groups of animals also showed significant IgG responses against BCG, but only animals immunized with PL-AL produced significant IgG responses against soluble cell wall proteins (SCWP) or whole cell lysate (WCL) of Mtb. Significant DTH responses against WCL were observed in both groups of animals after 24 h, but only PL-AL-immunized mice showed significant DTH responses after 48 h and 72 h. PL-Ms are capable of eliciting cross-reactive humoral and cellular responses against Mtb antigens and thus may be a potential vaccine strategy against tuberculosis.

Evaluación del potencial de Mycobacterium smegmatis como candidato vacunal contra la tuberculosis mediante estudios in sílico e in vivo / Evaluation of the potential of Mycobacterium smegmatis as vaccine Candidate against tuberculosis by in silico and in vivo studies

In this study, we scanned multiple published databases of gene expression in vivo of M tuberculosis at different phases of infection in animals and humans, to select 38 proteins that are highly expressed in the active, latent and reactivation phases. The selected proteins were predicted for T and B epitopes. For each proteins, the regions containing T and B epitopes were selected at the same time to look for identical epitopes on M smegmatis based on sequence alignments. Preliminary studies of humoral immunogenicity and cross-reactivity with M tuberculosis in mice using two M smegmatis-derived experimental vaccines were carried out, demonstrating the immunogenicity of M smegmatis proteoliposomes and the recognition of M tuberculosis proteins by the sera of animals immunized with this vaccine candidate. The conjunction of in silico and in vivo studies suggested the potential for future evaluation of M smegmatis as vaccine candidate against tuberculosis using different strategies.(AU)

En este estudio se revisaron múltiples bases de datos publicadas, relacionadas con experimentos de expresión de genes de M tuberculosis in vivo en diferentes estadios de la infeccción en humanos y animales. Se identificaron 38 proteínas con elevada expresión en las fases activa, latente y de reactivación de la infección. Se llevó a cabo la predicción de epítopes T y B en dichas proteínas. Las regiones de cada proteína que contenían simultàneamente epítopes T y B se seleccionaron y utilizaron para identificar regiones idénticas en M smegmatis mediante el alineamiento de secuencias. Se llevaron a cabo estudios de inmunogenicidad humoral y reactividad cruzada con M tuberculosis en ratones inmunizados con dos vacunas experimentales obtenidas a partir de M smegmatis, demostràndose la immunogenicidad de los proteoliposomas y el reconocimiento de proteínas de M tuberculosis por el suero de ratones vacunados con este candidato vacunal. Los resultados obtenidos con los estudios in sílico e in vivo sugieren la potencialidad para evaluación futura de candidatos vacunales obtenidos a partir de M smegmatis para la prevención de la tuberculosis(AU)

Prophylactic effect of administration of human gamma globulins in a mouse model of tuberculosis.

The protective effect of human gamma globulins on Mycobacterium tuberculosis infection was evaluated in a mouse model of intratracheal infection. Animals receiving human gamma globulins intranasally, 2h before intratracheal challenge showed a significant decrease in lung bacilli load compared to non-treated animals in different time intervals of up to 2 months after challenge. The same effect was obtained when M. tuberculosis was pre-incubated with the gamma globulin before challenge. The protective effect of the gamma-globulin formulation was abolished after pre-incubation with M. tuberculosis. These results suggest a potential role of specific antibodies in the defence against mycobacterial infections.

Obtención de albúmina de diferentes especies de mamíferos para uso inmunohematológico en bancos de sangre / Collection of albumin from different species of mammals for use in blood banks immunohematological

La albúmina juega un papel fundamental como componente básico en varios reactivos biológicos para uso diagnóstico. Para la obtención de esta proteína se utilizó plasma hemolítico de diferentes especies de mamíferos (bovina, equina, porcina y ovina), los cuales, fueron sometidos a un proceso de termocoagulación selectiva. Con vista a garantizar la polimerización necesaria se evaluaron diferentes concentraciones de glutaraldehído y glicina en las muestras de albúmina. A los productos finales se les determinaron: pH, concentración de proteínas y cloruro de sodio, contenido de hemopigmentos y polímeros, además se les realizaron ensayos inmunohematológicos que incluyeron: reacciones positivas no deseadas, capacidad potenciadora, presencia de IgG, sustancia de grupo sanguíneo ABO y Lewis y ausencia de actividad neuraminidasa. Se obtuvo un rendimiento promedio de 14.95 g/L, lográndose la polimerización adecuada al adicionar la misma concentración (0.06-.08%) de glutaraldehído y glicina. Las evaluaciones fisicoquímicas e inmunohematológicas realizadas a las muestras de albúminas resultaron satisfactorias, exceptuando el contenido de hemopigmento, que aunque no afectó el resultado del ensayo serológico, si influyó en la coloración final de la solución. En todos los casos las albúminas obtenidas podrían ser empleadas en los ensayos inmuno hematológicos de los bancos de sangre y servicios de transfusiones.

Obtención de albúmina de diferentes especies de mamíferos para uso inmunohematológico en bancos de sangre / Collection of albumin from different species of mammals for use in blood banks immunohematological

La albúmina juega un papel fundamental como componente básico en varios reactivos biológicos para uso diagnóstico. Para la obtención de esta proteína se utilizó plasma hemolítico de diferentes especies de mamíferos (bovina, equina, porcina y ovina), los cuales, fueron sometidos a un proceso de termocoagulación selectiva. Con vista a garantizar la polimerización necesaria se evaluaron diferentes concentraciones de glutaraldehído y glicina en las muestras de albúmina. A los productos finales se les determinaron: pH, concentración de proteínas y cloruro de sodio, contenido de hemopigmentos y polímeros, además se les realizaron ensayos inmunohematológicos que incluyeron: reacciones positivas no deseadas, capacidad potenciadora, presencia de IgG, sustancia de grupo sanguíneo ABO y Lewis y ausencia de actividad neuraminidasa. Se obtuvo un rendimiento promedio de 14.95 g/L, lográndose la polimerización adecuada al adicionar la misma concentración (0.06-.08%) de glutaraldehído y glicina. Las evaluaciones fisicoquímicas e inmunohematológicas realizadas a las muestras de albúminas resultaron satisfactorias, exceptuando el contenido de hemopigmento, que aunque no afectó el resultado del ensayo serológico, si influyó en la coloración final de la solución. En todos los casos las albúminas obtenidas podrían ser empleadas en los ensayos inmuno hematológicos de los bancos de sangre y servicios de transfusiones.(AU)

The effect of the administration of human gamma globulins in a model of BCG infection in mice.

The effect of the administration of a commercial preparation of human gamma globulins has been evaluated in a mouse model of intranasal infection with BCG. First, we demonstrated the passage of specific antibodies to saliva and lung lavage following the intranasal or intraperitoneal administration to mice of human gamma globulins. This treatment of mice inhibited BCG colonization of the lungs (p < 0.01). A similar inhibitory effect was observed after infection of mice with gamma globulin opsonized BCG organisms (p < 0.01). These results are relevant for the development of new strategies for the control and treatment of tuberculosis.