Milk and products derived from milk of dairy cows can harbor a variety of microorganisms and can be important sources of foodborne pathogens. The presence of foodborne pathogens in milk is due to direct contact with contaminated sources in the dairy farm environment and to excretion from the udder of an infected animal. Most milk is pasteurized, so why should the dairy industry be concerned about the microbial quality of bulk tank milk? There are several valid reasons, including (1) outbreaks of disease in humans have been traced to the consumption of unpasteurized milk and have also been traced back to pasteurized milk, (2) unpasteurized milk is consumed directly by dairy producers, farm employees, and their families, neighbors, and raw milk advocates, (3) unpasteurized milk is consumed directly by a large segment of the population via consumption of several types of cheeses manufactured from unpasteurized milk, (4) entry of foodborne pathogens via contaminated raw milk into dairy food processing plants can lead to persistence of these pathogens in biofilms, and subsequent contamination of processed milk products and exposure of consumers to pathogenic bacteria, (5) pasteurization may not destroy all foodborne pathogens in milk, and (6) inadequate or faulty pasteurization will not destroy all foodborne pathogens. Furthermore, pathogens such as Listeria monocytogenes can survive and thrive in post-pasteurization processing environments, thus leading to recontamination of dairy products. These pathways pose a risk to the consumer from direct exposure to foodborne pathogens present in unpasteurized dairy products as well as dairy products that become re-contaminated after pasteurization. The purpose of this communication is to review literature published on the prevalence of bacterial foodborne pathogens in milk and in the dairy environment, and to discuss public health and food safety issues associated with foodborne pathogens found in the dairy environment. Information presented supports the model in which the presence of pathogens depends on ingestion of contaminated feed followed by amplification in bovine hosts and fecal dissemination in the farm environment. The final outcome of this cycle is a constantly maintained reservoir of foodborne pathogens that can reach humans by direct contact, ingestion of raw contaminated milk or cheese, or contamination during the processing of milk products. Isolation of bacterial pathogens with similar biotypes from dairy farms and from outbreaks of human disease substantiates this hypothesis.

Staphylococcus aureus is a frequent cause of mastitis in dairy cows. However, pathogenesis of the infection has not been completely defined. We report the invasion of two strains of S. aureus into a bovine mammary epithelial cell line and a bovine mammary epithelial cell primary culture. Invasion of S. aureus into bovine mammary cells was time-dependent. Transmission electron microscopy of bovine mammary cells invaded by S. aureus showed intracellular replication of the bacterium within membrane-bound vacuoles. Invasion was reduced significantly when bovine mammary epithelial cells were treated with inhibitors of F-actin microfilament polymerization but not when these cells were treated with inhibitors of microtubule formation. Results indicated that S. aureus is capable of invading and replicating inside bovine mammary epithelial cells. Data also suggested that S. aureus invasion of bovine mammary epithelial cells requires active participation of specific components of the cytoskeleton of the epithelial cell.

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In 1956, Africanized bees began to spread in the American continent from southern Brazil, where original African bees mated with European bees. A few years later, in 1990, these Africanized bees reached the United States and were found in Texas. Currently, these hybrid bees are found in several North American states and will probably reach the Canadian border in the future. Although the presence of Africanized bees had produced positive effects on Brazilian economy, including improvement in crop pollination and in honey production, turning Brazil into a major exporter, the negative impacts-such as swarming, aggressive behavior, and the ability to mass attack-resulted in serious and fatal envenomation with humans and animals. Victims of bee attacks usually develop a severe envenomation syndrome characterized by the release of a large amount of cytokines [interleukins (IL) IL-1, IL-6, IL-8], and tumor necrosis factor (TNF). Subsequently, such cytokines produce an acute inflammatory response that triggers adverse effects on skeletal muscles; bone marrow; hepatic and renal functions; and cardiovascular, central nervous, and immune systems. Finally, the aim of the present review is to study historical characteristics and current status of Africanized bees' spread, the composition of their venom, the impact of the bees on the Brazilian economy and ecology, and clinical aspects of their stings including immune response, and to suggest a protocol for bee sting management since there is no safe and effective antivenom available.

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Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over used conventional antibiotics. Here we describe engineered triple-acting staphylolytic peptidoglycan hydrolases wherein three unique antimicrobial activities from two parental proteins are combined into a single fusion protein. This effectively reduces the incidence of resistant strain development. The fusion protein reduced colonization by Staphylococcus aureus in a rat nasal colonization model, surpassing the efficacy of either parental protein. Modification of a triple-acting lytic construct with a protein transduction domain significantly enhanced both biofilm eradication and the ability to kill intracellular S. aureus as demonstrated in cultured mammary epithelial cells and in a mouse model of staphylococcal mastitis. Interestingly, the protein transduction domain was not necessary for reducing the intracellular pathogens in cultured osteoblasts or in two mouse models of osteomyelitis, highlighting the vagaries of exactly how protein transduction domains facilitate protein uptake. Bacterial cell wall degrading enzyme antimicrobials can be engineered to enhance their value as potent therapeutics.

Introduction:In 1956, Africanized honeybees (AHB) migrated from Brazil to other regions of the Western Hemisphere, including South, Central, and North America, except for Canada. Despite being productive, they are highly aggressive and cause fatal accidents. This study aimed to evaluate patients at the Clinical Hospital of Botucatu Medical School (HC-FMB) and to propose treatment guidelines. Methods: From 2005 to 2006, the clinical and laboratorial aspects of 11 patients (7 male and 4 female) and the anatomopathological aspects of one patient who had died in 2003 were analyzed. Results: The age of the surviving patients varied from 5 to 87 years, with a mean of 42.5 years. The majority of accidents occurred in the afternoon, and the number of stings ranged from 20 to 500. The principal signs and symptoms were pain and local inflammatory signs, nausea, tachycardia, and vomiting. Biochemical findings presented increased levels of creatine phosphokinase, lactate dehydrogenase, and aspartate/alanine aminotransferase. An 11-year-old male patient died upon entering the attic of a two-storey building where he was attacked by a swarm, receiving more than 1,000 stings. He was sent to HC-FMB where he was treated, but he died 24h later. Observed at the autopsy were erythematous-purpuric skin lesions besides necrosis at the sting locations, rhabdomyolysis, focal myocardial necrosis, tubular hydropic degeneration and focal tubular acute necrosis of the kidneys, myoglobinuria, and centrolobular necrosis in the liver. Conclusions: Accidents caused by multiple AHB stings always constitute a medical emergency. As there is no specific antivenom, we have developed guidelines, including first aid, drugs, and the proper removal of stingers.

A study on the prevalence of Escherichia coli O157:H7 was conducted on 30 dairy farms in east Tennessee between May 2000 and April 2001. This pathogen was isolated from 8 of 30 (26.7%) dairy farms at various sampling times. A total of 415 fecal samples from cull dairy cows and 268 bulk tank milk samples were analyzed. Overall, 10 of 683 (1.46%) samples (2 of 268 [0.75%] milk samples and 8 of 415 [1.93%] fecal samples) tested positive for E. coli O157:H7. Food and Drug Administration Bacteriological Analytical Manual protocols were used for the conventional isolation and confirmation of E. coli O157:H7. Samples were shake cultured (150 rpm) at 42 degrees C for 24 h in tryptic soy broth containing 2 mg of novobiocin per liter. White colonies isolated on cefixime-tellurite sorbitol MacConkey agar plates were evaluated for fluorescence on sorbitol MacConkey agar supplemented with 0.025 g of methylumbelliferyl-beta-D-glucuronide per liter. Nonfluorescing white colonies were biochemically typed and serologically confirmed. Multiplex polymerase chain reaction profiles of E. coli O157:H7 isolates indicated the presence of common virulence factors (Shiga toxin, enterohemolysin, and intimin) of Shiga toxin-producing E. coli, suggesting the potential human pathogenicity of bacterial isolates. Pulsed-field gel electrophoresis profiles of SpeI and XbaI restriction enzyme-digested genomic DNA were used to establish relatedness among bacterial isolates. Data from this study indicate that both cull dairy cows and bulk tank milk pose a potential hazard with regard to human foodborne illness. It is therefore imperative to develop on-farm and preharvest pathogen reduction programs to control the carriage of E. coli O157:H7 pathogens.