Pathogenic Bacteria

The phylogeny of obligate intracellular coccoid parasites of acanthamoebae isolated from the nasal mucosa of humans was analyzed by the rRNA approach. The primary structures of the 16S and 23S rRNA molecules ofonestrainweredeterminedinalmostfulllength.Insituhybridizationwithahorseradishperoxidase-labeled oligonucleotide probe targeted to a unique signature site undoubtedly correlated the retrieved 16S rRNA sequence to the respective intracellular parasite. This probe also hybridized with the second

Background and Aim: Many local dairy products in Iran contain lactic acid bacteria. The aim of this study was to isolate and identify Lactobacillus brevis from the cottage cheese made in Bazoft city using biochemical and molecular methods and investigate its antimicrobial properties in vitro.
Materials and Methods: In this study, ten local Bazoft city cheese samples were collected. After transferring to the Lab, serial dilution was obtained at 10-6 CFU/mL and cultured in MRS medium. Then bacilli and gram-positive bacteria were isolated and identified by biochemical methods. The identified Lactobacillus brevis genome was extracted and then amplified using polymerase chain reaction (PCR) to confirm the isolated strain. Finally, the PCR product was sent to Sinaclon for sequencing. The antimicrobial properties of Lactobacillus brevis supernatant were evaluated using the disk and well diffusion method against Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, and Enterococcus faecalis. Antibiotic susceptibility was also assessed by the CLSI standard method.
Results:  Six species of Lactobacillus were identified from cottage cheese samples. Selected L. brevis showed good antimicrobial potency against five pathogenic bacteria. It showed the highest inhibitory effect against S. typhimurium during the well diffusion method with a mean diameter of growth inhibition zone of 19 mm and the least inhibitory effect against E. faecalis during the disc method with a growth inhibition zone diameter of 9 mm. It was also resistant to the antibiotics Vancomycin and Gentamicin, intermediate susceptible to Kanamycin and Nalidixic acid, and susceptible to Erythromycin, Tetracycline, Ampicillin, and Chloramphenicol.
Conclusion:  Isolated L. brevis strain from the local Bazoft cheese has a good antimicrobial ability. By performing extra in vitro and in vivo tests, this native strain can be used more in medicines and the food industry.

The aim of the present study was to evaluate the bacterial quality of chicken (n = 96) and turkey (n = 96) marketed in Casablanca, Morocco. Poultry samples (n = 192) were collected randomly from traditional shops and supermarkets during 2 sampling periods (hot and cold seasons). The samples were analyzed for the presence and counts of various bacteria. Results indicated that aerobic plate counts and fecal coliforms were particularly high in all the samples analyzed. Escherichia coli, coagulase-positive Staphylococcus, Clostridium perfringens, Salmonella, and Listeria monocytogenes were detected, respectively, in 48.4, 10.4, 7.2, 1.6, and 0.5% of the poultry meat samples. The chicken and turkey samples contained, respectively, 25 and 33.3% of bacteria above the maximum limits established by the Moroccan regulatory standards. The highest bacterial counts in poultry meat product samples were recorded with the traditional slaughtering process during the hot season (P < 0.05). These high levels of microbial contamination and occurrence of pathogenic bacteria reflect the poor hygienic quality of poultry meat under these conditions.

This chapter, written by several contributing authors, is devoted to discussing selected microbes of contemporary importance. Microbes from three categories are described by the following: (1) infectious invasive agents like Salmonella, Listeria monocytogenes, and campylobacter; (2) toxigenic pathogens such as Staphylococcus aureus, Bacillus cereus, and Clostridium botulinum; and (3) toxico-infectious agents like enterohemorrhagic Escherichia coli and Clostridium perfringens. In addition, emerging pathogens, like Cronobacter (Enterobacter) sakazakii, Arcobacter spp., and Mycobacterium avium subspecies paratuberculosis are also described.