The microbiome of bulk tank milk: Characterization and associations with somatic cell count and bacterial count.

Numerous studies have evaluated associations between bacterial groups and milk quality parameters. However, to our knowledge, no research has been published that has analyzed associations between the microbiome and quality parameters of bulk tank milk (BTM). Thus, the aims of this study were to identify the core microbiome of BTM and to examine associations between the microbiome and milk quality parameters. Four hundred seventy-two BTM samples from 19 different dairy farms located in New York State were analyzed by next-generation sequencing and quantitative PCR of the 16S rRNA gene to assess the milk microbiome and measure total bacterial load, respectively. Flow cytometry was used to determine bacterial and somatic cell counts. Heatmaps were constructed and simple linear regressions and response screening analysis were performed. To facilitate data analysis and interpretation of the results, we dichotomized the BTM samples into high (HSCC, >200,000) and low somatic cell count (LSCC, ≤200,000) and into high (HSPC, >3.6) and low log10 SPC (LSPC, ≤3.6). Spoilage-causing, spore-forming, and pathogenic bacteria of importance to the dairy industry were identified in the core microbiome. In addition, the taxa Thermoanaerobacterium and 5-7N15 were identified in the core microbiome; to our knowledge, these genera have not been previously identified in milk samples. Several bacterial genera were encountered in significantly higher relative abundances in the HSCC group when compared with the LSCC group, including Corynebacterium, Streptococcus, Lactobacillus, Coxiella, Arthrobacter, and Lactococcus. Additionally, several bacterial taxa were found in significantly higher relative abundances in the HSPC groups versus the LSPC groups: Acinetobacter, Enterobacteriaceae, Corynebacterium, and Streptococcus. In addition, Streptococcus was highly correlated with HSPC, and this genus was the second most abundant bacterial taxon detected in samples classified as HSCC. Bacterial diversity (Shannon index) was negatively correlated with bacterial load, suggesting that the microbiomes of high-bacterial load BTM samples are dominated by smaller groups of bacterial taxa. In conclusion, the associations described corroborated current knowledge about pathogens and spoilage bacteria in relationship to milk quality, and also indicated that other bacterial taxa should be a focus of further investigations.

The Lactococcus genus as a potential emerging mastitis pathogen group: A report on an outbreak investigation.

The bacterium Lactococcus lactis is widely used in food production and in medical applications, and is considered safe for human and animal use. However, studies have also linked Lactococcus bacteria to infection. For example, certain variants of Lactococcus species have been associated with bovine mastitis (e.g., Lactococcus lactis and Lactococcus garvieae). In this study, we investigated an outbreak of bovine mastitis thought to be associated with Lactococcus bacteria by using microbiological and molecular techniques. We used bacterial isolation, next-generation sequencing, DNA fingerprinting, and other methods to test our hypothesis that Lactococcus microbes were the primary pathogen causing the mastitis outbreak. Twenty-eight Lactococcus isolates were obtained from mastitic milk of 28 dairy cows. The isolates were identified as L. lactis (27 isolates) and L. garvieae (1 isolate). Phylogenetic analysis based on 16S rDNA gene sequence comparison indicated similarity among the L. lactis isolates as well as between the isolates and reference sequences. The DNA fingerprinting analysis based on random amplified polymorphic DNA results of the 27 L. lactis isolates identified different random amplified polymorphic DNA profiles, which suggests they originated from multiple sources. Microbiome analysis determined Lactococcus to be the dominant genus in the majority of the mastitic milk samples, whereas it was found in low relative abundance in healthy milk samples. The Lactococcus genus was detected in all environmental samples tested, and sampling of bulk tank milk corroborated that Lactococcus was not abundant in healthy milk from the same dairy herd. In summary, our findings suggest that Lactococcus bacteria are a potential etiological agent in the mastitis outbreak studied. Further studies should be conducted to understand the importance of Lactococcus, especially L. lactis, as pathogenic microbes in veterinary medicine and food safety.

The infectious disease epidemiologic triangle of bovine uterine diseases

Postpartum uterine diseases are important for animal welfare and economic reasons, causing cow discomfort, elimination from the herd and impaired reproductive performance. Metritis is characterized as an abnormally enlarged uterus and a fetid, watery, red-brown uterine discharge within 21 days after parturition. Endometritis is defined as inflammation of the endometrium after 21 days postpartum without systemic signs of illness, and can be considered the chronic stage of uterine inflammation. It has been reported that the metritis affects 10 to 20% of cows, and endometritis affects 5.3 to 52.6% of cows. Metritis affects the cow systemically, and has a negative impact on milk production and reproductive performance. Cows affected with endometritis are not systemically ill, and do not have their milk production altered; however, they have impaired reproductive performance. Metritis and endometritis are complex multifactorial diseases, and a wide range of factors contributes to their occurrence. They are often associated with mixed bacterial infection of the uterus, and the major pathogens associated with uterine diseases are Escherichia coli, Trueperella pyogenes and Fusobacterium necrophorum. Events during the transition period related to negative energy balance and metabolic imbalance, mineral deficiencies, leading to immunosuppression are of great important during establishment of intrauterine bacterial infections. This, combined with endometrium trauma events during parturition (such as calving related problems), and environmental factors (poor hygiene at calving, housing type and calving season), increases the risk of metritis and endometritis.

The infectious disease epidemiologic triangle of bovine uterine diseases

Postpartum uterine diseases are important for animal welfare and economic reasons, causing cow discomfort, elimination from the herd and impaired reproductive performance. Metritis is characterized as an abnormally enlarged uterus and a fetid, watery, red-brown uterine discharge within 21 days after parturition. Endometritis is defined as inflammation of the endometrium after 21 days postpartum without systemic signs of illness, and can be considered the chronic stage of uterine inflammation. It has been reported that the metritis affects 10 to 20% of cows, and endometritis affects 5.3 to 52.6% of cows. Metritis affects the cow systemically, and has a negative impact on milk production and reproductive performance. Cows affected with endometritis are not systemically ill, and do not have their milk production altered; however, they have impaired reproductive performance. Metritis and endometritis are complex multifactorial diseases, and a wide range of factors contributes to their occurrence. They are often associated with mixed bacterial infection of the uterus, and the major pathogens associated with uterine diseases are Escherichia coli, Trueperella pyogenes and Fusobacterium necrophorum. Events during the transition period related to negative energy balance and metabolic imbalance, mineral deficiencies, leading to immunosuppression are of great important during establishment of intrauterine bacterial infections. This, combined with endometrium trauma events during parturition (such as calving related problems), and environmental factors (poor hygiene at calving, housing type and calving season), increases the risk of metritis and endometritis.(AU)

Phenotypic plasticity of male Schistosoma mansoni from the peritoneal cavity and hepatic portal system of laboratory mice and hamsters.

Morphometric analysis of Schistosoma mansoni male worms obtained from AKR/J and Swiss mice was carried out. Rodents infected by the intraperitoneal route with 80 cercariae of the schistosome (LE strain) were killed by cervical dislocation at 45 and 60 days post-infection and both peritoneal lavage and perfusion of the portal system were performed for the recovery of adult worms. Characteristics including total body length, the distance between oral and ventral suckers, extension of testicular mass and the number of testes were considered in the morphological analysis. Changes that occurred in S. mansoni recovered from the peritoneal cavity or from the portal system of AKR/J and Swiss mice included total body length and reproductive characteristics. Significant morphometric alterations were also observed when worms recovered from the portal system of both strains of mice were compared with the schistosomes obtained from hamsters (Mesocricetus auratus), the vertebrate host in which the LE strain had been adapted and maintained by successive passages for more than four decades. The present results reinforce the idea that S. mansoni has high plastic potential and adaptive capacity.

Oral paracoccidioidomycosis: a retrospective study of 62 Brazilian patients.

OBJECTIVE: The purpose of this study was to evaluate retrospectively the profile of patients with oral paracoccidioidomycosis referred to two Dental Schools in Belo Horizonte (MG, Brazil) between 1955 and 1998. Despite the importance of the oral manifestations of this disease, few papers in the English literature have provided epidemiological data. SUBJECTS AND METHODS: The medical records of 62 patients presenting oral paracoccidioidomycosis were reviewed in detail. Patient age, gender, race, occupation, site of lesion and type of clinical manifestation of the disease were tabulated. RESULTS: There was a predominance of male patients (97%), with a male:female ratio of 30:1. The mean age was 40 years. Most of the patients were farm workers (53%). Some patients presented multiple oral lesions (19 cases, 30%). The fungal lesions were found principally in the alveolar process and gingiva, but were also seen on the palate, lip and buccal mucosa. All patients had chronic proliferative mulberry-like ulcerated oral lesions and the diagnosis was confirmed histologically. The clinical records did not contain notes about pulmonary involvement by the lesions. CONCLUSION: The purpose of this study was to describe the epidemiological profile of a specific population with the diagnosis of oral paracoccidioidomycosis. The major goal is to establish a scientific basis for initiating educational programs for prevention and early diagnosis of oral paracoccidioidomycosis.

Oogram studies in mice infected with Schistosoma mansoni and treated with dexamethasone.

Mice infected with about 90 cercariae of Schistosoma mansoni (LE strain) were treated during five consecutive days with dexamethasone (50 mg/Kg, subcutaneously), starting on the 42nd day of infection. Groups of five mice were then daily sacrificed from the first day after onset of treatment until the first day after. The perfusion of the portal system was performed and a piece of the intestine was processed for qualitative and quantitative oograms. This treatment carries to larger numbers of eggs in the tissues of treated mice, when compared with untreated groups. No changes were observed in the kinetics of oviposition, as all stages of viable eggs were observed in the tissues of treated and control mice. These data reinforce the hypothesis of a partial blockade of the egg excretion in immunosuppressed mice.

Schistosoma mansoni: the effect of dexamethasone on the cercaria-schistosomulum transformation, in vivo.

Treatment with dexamethasone (DMS) in the early phases of the experimental Schistosoma mansoni infection causes an indirect effect on the cercaria-schistosomulum transformation process. This is observed when naive albino mice are treated with that drug (50 mg/Kg, subcutaneously) and infected intraperitoneally 01 hour later with about 500 S. mansoni cercariae (LE strain). An inhibition in the host cell adhesion to the larvae, with a simultaneous delay in the cercaria-schistosomulum transformation, is observed. This effect is probably due to a blockade of the neutrophil migration to the peritoneal cavity of mice, by an impairment of the release of chemotactic substances. Such delay probably favors the killing of S. mansoni larvae, still in the transformation process, by the vertebrate host defenses, as the complement system.

[Schistosoma mansoni development in the peritoneal cavity of inbred AKR/J mice]. / Desenvolvimento do Schistosoma mansoni na cavidade peritoneal de camundongos da linhagem AKR/J.

Cercariae of Schistosoma mansoni after intraperitoneal inoculation, developed and reached the sexual maturation in that site with egg production. In the AKR/J strain of mice, 7.7% of the peritoneal recovered females showed normal eggs in the uterus. No evidence of hemoglobinic pigment in their digestive tract was observed in the peritoneal recovered parasites from both strains (AKR/J and SWISS). This fact suggests that the parasites can develop without red blood cells ingestion. On the other hand, the development of the parasite with egg production in the peritoneal cavity of the AKR/J mouse reinforces the data that the lung phase is not necessary for the development of the parasite.

Kinetics of the pulmonary phase of Schistosoma mansoni in mice treated with dexamethasone.

In the experimental schistosomiasis mansoni glucocorticoids cause a reduction in the worm burden when administered in the week of infection or, the longest, at the next week. In order to determinate the probable(s) site(s) of reduction of the worm burden, mice were infected with cercariae of LE strain of S. mansoni and dexamethasone was administered daily (50 mg/kg, subcutaneously) starting 1 hour before infection until the eighth day. Mice were sacrificed daily starting on the third day after infection until the ninth day, and schistosomula from lungs were collected. Six weeks after infection, the remaining mice were sacrificed and perfused for adult worm recovery. Analysis of the results showed that the non-treated mice presented larger numbers of lung larvae than the treated ones, and this difference was also found later in the worm burden in the portal system. This difference may reflect the early death of larvae in treated animals, before or after reaching the lungs.

The effect of stepwise iodination on biological properties of Bothrops jararaca venom.

By titrating 5 mg of native venom with aliquots of a 2 x 10(-2) M iodine monochloride solution, neutralization of lethality by the incorporation of iodine was found with 200 +/- 5 microliters of solution, and above, up to 310 +/- 10 microliters, when saturation with iodine was attained. Doses up to 1500 micrograms (equivalent to 32 LD50 of native venom), where injected i.p. in mice without lethal effects. Proteolytic, phospholipase A2 and esterolytic activities were greatly reduced, but a low activity persisted even in fully iodinated samples. Direct hemolysis was markedly inhibited, and incapacity to coagulate fibrinogen and horse plasma was also observed in the iodinated samples. Hemorrhage and necrosis in rat skin, caused by 20 micrograms of iodinated venom were not elicited by doses up to 120 micrograms of iodinated anavenom. In mice, the myonecrosis that resulted from direct i.m. injection of native venom, and the massive hemorrhage caused by 5 LD50 doses injected i.p. were abolished by venom iodination. Blood congestion in liver, spleen, kidneys, and lungs, almost disappeared with iodination to the level of neutralization, and was barely seen with venom samples iodinated to saturation. The clinical signs of impaired physical activity, appearing in mice injected with 700 to 1500 micrograms of the iodinated anavenom were intensified by captopril and attenuated by epinephrine.