Cyanobacteria, as one of the largest groups of phototrophic bacteria, have a high potential as an excellent source of fine chemicals and bioactive compounds, including lipid-like compounds, amino acid derivatives, proteins, and pigments. This study aimed to synthesize ZnO nanoparticles using the cell extract of the cyanobacterium Nostoc sp. EA03 (CEN-ZnO NPs) through a rapid and eco-friendly approach. The biosynthesized nanoparticles, CEN-ZnO NPs, were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), zeta potential measurement, differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA), FTIR, SEM, TEM, and EDX spectroscopy. The UV-Vis spectrum showed an absorption peak at 370 nm. The star-shaped CEN-ZnO NPs, as observed in the TEM and SEM images, had an average diameter of 50-80 nm. MIC and MBC values for E. coli, P. aeruginosa and S. aureus, were determined to be, respectively, 2000, 2000, and 64 mg ml À1 , and 2500, 2500 and 128 mg ml À1 . Further analysis through confocal laser scanning microscopy (CLSM) provided the observable confirmation that the CEN-ZnO NPs stunted the bacterial growth, preventing the formation of exopolysaccharides. The AFM analysis of surface topography of bacterial biofilm samples treated with CEN-ZnO NPs showed a rugged topography in some parts of the biofilm surface, indicating the destruction of biofilms. In contrast, in the untreated control samples, the structured biofilms were flat and prominent. MTT assay indicated that CEN-ZnO NPs had less cytotoxicity on the MRC-5 lung fibroblast cells compared with the cancerous treated A549 cells. As the concentration of the CEN-ZnO NPs increased, the amount of ROS produced in the tested bacterial strains also increased. Analyzing the data obtained from flow cytometry showed that the higher concentrations of CEN-ZnO NPs lead to a reduction in the viability of P. aeruginosa PAO1, E. coli and S. aureus. The biosynthesized ZnO nanoparticles using Nostoc cell extracts exhibited different attributes, inspiring enough to be considered for further investigation.

Mycobacterium avium complex (MAC) and Mycobacterium avium paratuberculosis (MAP) cause zoonotic infections transmitted by birds and livestock herds. These pathogens have remained as serious economic and health threats in most areas of the world. As zoonotic diseases, the risk of development of occupational disease and even death outcome necessitate implementation of control strategies to prevent its spread. Zoonotic MAP infections include Crohn’s disease, inflammatory bowel disease, ulcerative colitis, sarcoidosis, diabetes mellitus, and immune‐related diseases (such as Hashimoto’s thyroiditis). Paratuberculosis has classified as type B epidemic zoonotic disease according to world health organization which is transmitted to human through consumption of dairy and meat products. In addition, MAC causes pulmonary manifestations and lymphadenitis in normal hosts and human immunodeficiency virus (HIV) progression (by serotypes 1, 4, and 8). Furthermore, other subspecies have caused respiratory abscesses, neck lymph nodes, and disseminated osteomyelitis in children and ulcers. However, the data over the occupational relatedness of these subspecies is rare. These agents can cause occupational infections in susceptible herd breeders. Several molecular methods have been recognized as proper strategies for tracking the infection. In this study, some zoonotic aspects, worldwide prevalence and control strategies regarding infections due to MAP and MAC and related subspecies has been reviewed.

Silicotuberculosis is critical in community settings among workers and employees exposed to silica dust. Older age of entry (>30 years), male sex, infection with human immunodeficiency virus (HIV), exposure duration, smoking, chronic obstructive pulmonary disease, migration, the severity of the silicosis and the intensity of the exposure are potential risk factors. Lack of timely diagnosis and treatment for tuberculosis (TB) may also raise the rate of infection; previous treatment of TB is possibly associated with the development of silicotuberculosis in more than half of patients, increasing with age (>40 years). Identification of risk factors benefits not only the academic research community, but also the workers or employees and policy making. Some strategies can be implemented, such as controlling or reducing exposure to silica dust, ensuring continuity of treatment of TB or extended anti-TB treatment, management of the situation by occupational health professionals, prevention of oscillating migration, providing workers with compensation, training and education in occupational health, improving the quality of life of miners and workers, intensive medical surveillance and TB screening in routine health check ups, and policy making for higher immunity to inhibit inhalation of dust by workers or employees.

Probiotics include a group of microorganisms with numerous effects acting as normal flora and masking binding sites of pathogens and inhibition of their colonization. Most common probiotic species include Bifidobacterium spp., Lactobacilli and Saccharomyces boulardii. Some other beneficial properties of probiotics include cancer prevention, reduction of blood cholesterol and its absorption from the intestine (by bile digestion), stimulation and strengthen of the immune system, treatment and prevention of acute diarrhea, reducing inflammation in the intestines, and food allergies or eczema in children, improving the symptoms of irritable bowel syndrome and colitis, and remedy of vaginal yeast infections, and also antibiotics associated diarrhea, oral lesions, dental caries, and vaginal swelling. Furthermore, probiotics contribute to prevent viral infections, athlete's foot and fungal infections, and improvement of digestion and enhancing nutrition absorbance, inhibition of biofilm formation and increase in vitamins biosynthesis; especially those in groups B and K. Probiotics use in defined amounts has desirable outcomes. Side effects of probiotics are rare which occur among immunocompromised patients and pediatrics, thus care should be taken to avoid their side effects. Use of germ-free animals and study of symbiotic interactions among probiotics is possibly helpful for future perspectives.

The ability of biofilm formation in methicillin-resistant Staphylococcus aureus (MRSA) causes significant mortality and morbidity in wound infections. Nanoparticles because of the drug concentration increment at the point of contact of nanoparticles and bacteria, and slower release of the drug at the desired location are considered as proper tools to overcome the therapeutic problem of antimicrobial-resistant infections. This study was aimed to evaluate the anti-biofilm activity of cefazolin-loaded nanoparticles against MRSA isolates. The 27 clinical isolates of MRSA were collected from patients with pressure sores and diabetic ulcers referred to Loghman Hospital in Tehran—Iran. MRSA isolates were detected by polymerase chain reaction (PCR) and biochemical tests. Cefazolin-loaded niosome was synthesized using the thin-film hydration method and were characterized by zeta potential measurement and transmission electron microscopy (TEM). The round-shaped cefazolin-loaded niosomes had a diameter of 100 nm and a −63 mV zeta potential. The cefazolin-containing niosomes removed 1, 3, and 5 d old biofilms at the concentration of 128 µg ml−1, 128 µg ml−1, and 256 µg ml−1, respectively. Histological results indicated that BALB/c mice receiving cefazolin-loaded niosomes were treated effectively faster than those treated by cefazolin or untreated group. In conclusion, the cefazolin-loaded niosome could be considered as a promising candidate for the treatment of biofilm-mediated infections of MRSA.