Background Colonization by livestock-associated MRSA (LA-MRSA) has increasingly been reported in the swine population worldwide. The aim of this study was to assess the prevalence of MRSA nasal carriage in healthy pigs, including the black ( Calabrese ) breed, from farms in the Calabria Region (Southern Italy). Between January and March 2018, a total of 475 healthy pigs reared in 32 farms were sampled by nasal swabbing. MRSA isolates were characterized by spa , MLST and SCC mec typing, and susceptibility testing to 17 antimicrobials. Results 22 of 32 (66.8%) pig farms resulted positive for MRSA. The prevalence of MRSA was 46.1% (219 MRSA culture-positive out of 475 samples). MRSA colonization was significantly higher in intensive farms and in pigs with a recent or ongoing antimicrobial treatment. All 219 MRSA isolates were assigned to ST398. The most common spa types were t011 (37.0%), t034 (22.4%) and t899 (15.1%). A novel spa type (t18290) was detected in one isolate. An insertion of IS 256 in the ST398-specific A07 fragment of the SAPIG2195 gene was detected in 10 out of 81 t011 isolates. Nearly all isolates carried the SCC mec type V element, except 11 isolates that carried the SCC mec type IVc. None of the isolates was positive for the Panton-Valentine leukocidin. All isolates were resistant to tetracycline. High resistance rates were also found for clindamycin (93.1%), trimethoprim/sulfamethoxazole (68.4%), fluoroquinolones (47.9–65.3%) and erythromycin (46.1%). None of the isolates was resistant to vancomycin and fusidic acid. Overall, a multidrug resistant phenotype was observed in 88.6% of isolates. Conclusions We report a high prevalence of MRSA among healthy swine in Southern Italy farms, with higher isolation frequency associated with intensive farming. The epidemiological types identified in our study reflect those reported in other European countries. Our findings underscore the importance of monitoring the evolution of LA-MRSA in pig farms in order to implement control measures and reduce the risk of spread in the animal population. Electronic supplementary material The online version of this article (10.1186/s12866-019-1422-x) contains supplementary material, which is available to authorized users.
BackgroundLivestock-associated methicillin-resistant Staphylococcus aureus (MRSA) belonging to clonal complex 398 is recognized as an occupational hazard for workers employed in intensive animal husbandry, especially in the swine-breeding chain. In this study, we compared the prevalence and epidemiological type of MRSA isolates from swine and farm workers in a large area of southern Italy.MethodsBetween January and March 2018, 88 workers from 32 farms where we had previously performed a survey for MRSA colonization of farmed pigs, were sampled by nasal swabbing. A follow-up investigation was conducted on seven workers 1 year after primary screening. MRSA isolates were characterized by MLST, spa and SCCmec typing, and tested for susceptibility to 15 antimicrobials. Epidemiological correlations between human and swine MRSA isolates were supported by Rep-MP3 and RAPD PCR fingerprinting, and whole-genome sequencing.ResultsThe overall colonization rate of MRSA in swine farm workers was 21.6%, being significantly higher in intensive farms and in workers with direct animal contact. All human MRSA isolates were multi-drug resistant, belonged to the ST398 livestock clade, and did not carry Panton-Valentine leukocidin and enterotoxin genes. Notably, 94.1% of human MRSA isolates belonged to the same epidemiological type as swine MRSA isolates from the corresponding farm. Persistent MRSA carriage was documented in some workers 1 year after primary sampling.ConclusionsWe report a high prevalence of MRSA among swine farm workers, with higher colonization rates associated with intensive breeding and animal exposure. Our findings suggest unidirectional animal-to-human transmission of LA-MRSA and denote the high zoonotic transmissibility of the ST398 livestock clade.
Several foodborne human pathogens, when exposed to harsh conditions, enter viable but nonculturable (VBNC) state; however, still open is the question whether VBNC pathogens could be a risk for public health, because, potentially, they can resuscitate. Moreover, cultural methods for food safety control were not able to detect VBNC forms of foodborne bacteria. Particularly, it has not been established whether food chemophysical characteristics can induce VBNC state in contaminating pathogen bacterial populations, especially in food, such as salads and fresh fruit juices, not subjected to any decontamination treatment. In this preliminary study, we intentionally contaminated grapefruit juice to determine whether pathogen bacteria could enter VNBC state. In fact, grapefruit juice contains natural antimicrobial compounds, has an average pH of about 3 and low content in carbohydrates. Such characteristics make grapefruit juice a harsh environment for microbial survival. For this purpose, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium ATCC 14028, Listeria monocytogenes ATCC 7644, and Shigella flexneri ATCC 12022, at two different inoculum sizes, have been used. Viability by the LIVE/DEAD BacLight Bacterial Viability kit and culturability by plate counts assay were monitored, whereas "resuscitation" of nonculturable populations was attempted by inoculation in nutrient-rich media. The data showed that L. monocytogenes lost both culturability and viability and did not resuscitate within 24 h independently on inoculum size, whereas E. coli O157:H7 was able to resuscitate after 24 h but did not after 48 h. Salmonella Typhimurium and S. flexneri, depending on inoculum size, lost culturability but maintained viability and were able to resuscitate; moreover, S. flexneri was still able to form colonies after 48 h at high inoculum size. In conclusion, entry into VBNC state differs on the species, depending, in turn, on inoculum size and time of incubation.
Exposure to biological agents and dusts occurs in homes and occupational environments and it is known to cause adverse health effects. There is limited information concerning the occupational exposure levels of airborne biohazard during wood processing, but this exposure is associated with a range of adverse health effects. Control of exposure to microbiological hazards and dust in woodworking is not easy. In fact, various types of wood are commonly used and they generate complex mixtures of dusts and biological agents with various health risks. The aim of this study was to investigate the concentration of dust, bacteria, and endotoxins encountered in six different wood factories. These people were exposed to between 0.05 and 12.00 mg inhalable dust m(-3) and between 0.40 and 6.93 ng inhalable endotoxins m(-3). Total bacteria concentrations in the air of the factories examined were within a range of 130-2000 CFU m(-3), the value of Gram negative was within a 0-164 CFU m(-3), and the concentration of Gram positive was within 1-104 CFU m(-3). In conclusion, people working in wood factories may be exposed to high levels of inhalable dust and endotoxins.
In recent years proof of "indoor air quality", designed to protect and improve the health and safety of workers, was a central strategy in the prevention of many companies. The man creates with the environment in which he lives and works a continuous gas exchange through breathing; this makes the respiratory system main entrance of air pollutants. The indoor pollutants are numerous and originate from different sources. Their concentration may vary over time and depends on the nature of the source, on ventilation, habits and activities carried out by the occupants in the areas concerned. It is well known that photocopiers and laser printers are equipment that emit several chemicals (ozone, solvents, toner dust) both to release the materials used for their operation (toner, ink, paper) and then to the special printing technology used. During the printing and photocopying processes occurring chemical and physical processes complex, during which the components of toner and paper will react under the influence of light and high temperatures. More recently, there have been a growing number of articles as a result of indoor air pollution. They have become more and more significant; probably because of increasing of the concentrations of harmful substances in the confined environment. Particular attention has been given to the emission of harmful substances from electronic equipment and printing that are increasingly present in living and working place. This work was the main objective the emission of volatile organic compounds, formaldehyde and ozone from laser printing devices and consequently the estimation of elimination of same substances through a paper filters which operate through a mechanism of filtration surface with interstitial and penetration of particles into matrix filter on agglomeration, they also enclose type sandwich a layer of activated carbon.
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