BackgroundProbiotics, live cells with different beneficiary characteristics, have been extensively studied and explored commercially in many different products in the world. Their benefits to human and animal health have proven in hundreds of scientific studies. Based on rich bibliographic material, Curd is the potential source of probiotic Lactobacilli.MethodThe aim of the present study was to observe Lactobacilli with probiotic potential activities from different curd samples for isolation, identification and characterization of Lactobacillus species.ResultsAmong the samples, thirty lactic acid bacterial strains were isolated, sixteen (16/30) best Lactobacillus isolates were selected by preliminary screening as potential probiotic for acid and bile tolerance, further confirmed using 16s rRNA identification. All the selected Lactobacillus isolates were then characterized in vitro for their probiotic characteristics and antimicrobial activities against pathogens and aggregation studies. The results indicated that selected potential probiotic isolates (T2, T4 and T16) were screened and confirmed as Lactobacillus. The isolates produced positive tolerance to excited pH, NaCl and bile salts, also revealed noticeable antimicrobial activities against pathogens. All the Lactobacillus isolates were susceptible to clinical antibiotics used. Besides, T2 isolate was constituted to retain stronger auto and co-aggregation and cell surface hydrophobicity capacity.ConclusionBased on the drawn results, T2, T4 and T16 Lactobacillus isolates were recognised as ideal, potential in vitro antimicrobial probiotic isolates against pathogens and studies are needed further in-vivo assessment and human health benefits in their real-life situations.

The synthesis of biogenic nanoparticles from non-chemical resources has increased the drive toward understanding infection biology. Accordingly, we aimed to address the symbiotic antibiofilm effect of biogenic copper and zinc oxide nanoparticles with antimicrobials against multidrug resistant (MDR) pathogens. The minimum inhibitory concentration (MIC) of copper nanoparticles (CuNPs) and zinc oxide nanoparticles (ZnONPs) at the range from 2 to 128 lg/ml was calculated against Grampositive and Gram-negative pathogenic bacteria using a broth dilution method. Both nanoparticles have prime antibacterial activity compared with standard antibiotics (excluding against P.aeruginosa MTCC 741). A qualitative assessment of biofilm formation and collegial effect was performed using a modified test tube and the microtiter plate-based method by measuring the optical density and time kill of nanoparticles. The results demonstrated efficient antibiofilm activity of CuNPs in its lowest concentration than ZnONPs and antibiotics itself. In addition, significant enhancing antibiofilm effect was also shown by CuNPs in the presence of third generation antibiotics against Gram-negative and Gram-positive bacteria. A scanning electron microscopy (SEM) analysis was used to investigate the effect of the nanoparticles on morphological changes of Staphylococcus aureus. Current data highlights, biogenic CuNPs and ZnONPs could be used as an adjuvant for antibiotics in the treatment of bacterial infections.

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Bacterial infections of the central nervous system, especially acute infections such as bacterial meningitis require immediate, invariably empiric antibiotic therapy due to the widespread emergence of resistance among bacterial species. Nosocomial infections by Pseudomonas aeruginosa have been described with an increasing trend towards multidrug resistance. P. aeruginosa isolates n = 53 (66%) isolated from the cerebrospinal fluid (CSF) were used for this study. Antibiotic resistance in 53 P. aeruginosa clinical isolates from 80 CSF samples were evaluated. Of these, n = 42 (80%) of the isolates showed multidrug resistance to more than eight antibiotics and n = 17 (32%) isolates were found to be imipenem resistant P. aeruginosa (IMPR-Pa). Genotypical examination by ERIC based PCR revealed minor genetic variations. Polymicrobial infections are common in the CSF samples. However, high prevalence of P. aeruginosa as an opportunistic pathogen has been developing with increased resistance to antimicrobial agents and thus becoming a significant threat.

Aminoglycoside resistance in six clinically isolated Staphylococcus aureus was evaluated. Genotypical examination revealed that three isolates (HLGR-10, HLGR-12, and MSSA-21) have aminoglycoside-modifying enzyme (AME) coding genes and another three (GRSA-2, GRSA-4, and GRSA-6) lacked these genes in their genome. Whereas isolates HLGR-10 and HLGR-14 possessed bifunctional AME coding gene aac(6')-aph(2''), and aph(3')-III and showed high-level resistance to gentamycin and streptomycin, MSSA-21 possessed aph(3')-III and exhibited low resistance to gentamycin, streptomycin, and kanamycin. The remaining three isolates (GRSA-2, GRSA-4, and GRSA-6) exhibited low resistance to all the aminoglycosides because they lack aminoglycoside-modifying enzyme coding genes in their genome. The transmission electron microscopy of the three isolates revealed changes in cell size, shape, and septa formation, supporting the view that the phenomenon of adaptive resistance is operative in these isolates.