Drought and salinity stresses induced physio-biochemical changes in sugarcane: an overview of tolerance mechanism and mitigating approaches.

Sugarcane productivity is being hampered globally under changing environmental scenarios like drought and salinity. The highly complex nature of the plant responses against these stresses is determined by a variety of factors such as genotype, developmental phase of the plant, progression rate and stress, intensity, and duration. These factors influence plant responses and can determine whether mitigation approaches associated with acclimation are implemented. In this review, we attempt to summarize the effects of drought and salinity on sugarcane growth, specifically on the plant's responses at various levels, viz., physiological, biochemical, and metabolic responses, to these stresses. Furthermore, mitigation strategies for dealing with these stresses have been discussed. Despite sugarcane's complex genomes, conventional breeding approaches can be utilized in conjunction with molecular breeding and omics technologies to develop drought- and salinity-tolerant cultivars. The significant role of plant growth-promoting bacteria in sustaining sugarcane productivity under drought and salinity cannot be overlooked.

Antibacterial activity and mechanism of essential oils in combination with medium-chain fatty acids against predominant bovine mastitis pathogens.

Bovine mastitis has become a significant economic importance for the dairy industry. Concerns regarding poor milk quality and emergence of bacterial resistance have necessitated to develop an alternative therapeutic approach to antibiotics for the treatment of mastitis. Saturated medium-chain fatty acids (MCFAs) and essential oils (EOs) are known natural antimicrobials, but their combined effect has not been investigated extensively. The objective of the present investigation was to examine the bactericidal effect of various combined treatments of eight EOs and three saturated MCFAs to inactivate predominant mastitis pathogens, including Staphylococcus aureus ATCC 29213; Escherichia coli ATCC 25922; Klebsiella pneumoniae ATCC 27736 and Streptococcus agalactiae ATCC 27956. The minimum inhibitory concentration (MIC) values confirmed that all the tested pathogens were variably susceptible to both EOs and saturated MCFAs. Among essential oils, carvacrol (CAR), trans-cinnamaldehyde (TC) and thymol (TM) showed the highest inhibitory activity at concentration 0·38-1·32 mg/mL. Carvacrol exhibited effective additive antibacterial activity in combined treatment with octanoic acid (OA) in terms of its fractional inhibitory index (0·63-0·88) and time-kill effect in reducing about 6 log CFU/mL bacterial cells in less than 5 min. The effort was also made to elucidate the mechanism of antibacterial action of CAR and OA against selected mastitis pathogens by observing changes in cell microstructure, permeability and integrity of cell membrane and their membrane potential. After adding CAR and OA at MIC level, there were obvious changes in cell morphology, leakage of small electrolytes and macromolecules at the initial few hours of treatment i.e. within 1-2 h were observed. Our results indicated that CAR and OA could be evaluated as alternatives or adjuncts to antibiotics as intramammary infusion or topical application to treat bovine mastitis, significantly improving the microbiological safety of milk.

Efficacy and mechanism of carvacrol with octanoic acid against mastitis causing multi-drug-resistant pathogens.

In the present investigation, we determined the in vitro antimicrobial activity of eight essential oils (EOs) and three medium-chain fatty acids (MCFAs) alone and in combination against Staphylococcus aureus ATCC 700698, Klebsiella pneumoniae ATCC 700603, and E. coli FcW5. The interactions between EOs and MCFAs were determined by fractional inhibitory concentration indices. Moreover, mode of action of selected bioactive components was studied by changes in bacterial surface charge, morphology, and membrane integrity assays. Among EOs, carvacrol (CAR), trans-cinnamaldehyde (TC), and thymol (TM) showed strong antimicrobial activity. In combination study, CAR+OA (octanoic acid), CAR+DA (decanoic acid), and TM+OA were observed as the most significant (P≤0.05) which were also confirmed through time-kill plots. Based on these results, CAR+OA were found to be most efficacious in terms of killing time (P≤0.05). Changes in the surface charge, morphology, and membrane integrity upon the combined treatment of CAR+OA were also observed, which ultimately leads to cell death. Results suggest that CAR+OA when used in combination offer a significant (P≤0.05) additive antimicrobial activity against the selected pathogenic bacteria. Therefore, these natural bioactive molecules could be interesting alternatives to conventional therapy for the control of mastitis caused by multi-drug-resistant pathogens in bovine animals to ensure the milk safety.

Distribution of Hepatitis C Virus Genotypes in Bahrain.

BACKGROUND: Approximately 170 million people are infected with Hepatitis C virus (HCV) worldwide, making it one of the world's major infectious diseases. There are no published population based studies about the prevalence of HCV genotypes in Bahrain. OBJECTIVES: Therefore, the aim of the present study was to investigate the prevalence and distribution of HCV genotypes and subtypes among a large sample of patients with chronic HCV infection in Bahrain. PATIENTS AND METHODS: Serum samples were collected from 202 HCV positive patients; of them 128 had a viral load (> 500 IU/mL) suitable for the type-specific genotyping assay. Gender-wise and age-wise differences in the distribution of HCV genotypes were determined by Chi Square and Fisher's Exact tests. RESULTS: The predominant genotype among Bahraini patients was type 1 (36.71%), followed by genotypes 3 and 4 (15.6% each) and the lowest frequency was found for genotype 2 (3.9%). Among genotype 1, subtype 1b had the highest frequency (21.09%), followed by subtype 1a (14.06%). Among genotype 3, subtype 3a had the highest frequency (11.72%), while among genotype 4, most of subtypes were undetermined. The frequency of all different HCV genotypes was higher in male patients compared to female patients. Genotype 1 was most common in the age group of 51 - 60 years (38.3%), genotype 2 in 21 - 30 years (60%) and genotype 3 in 51 - 60 years (30%), while genotype 4 was most frequent among the age group > 61 (40%). CONCLUSIONS: The most common HCV genotype in Bahrain was subtype 1b followed by 1a and 3a. Further studies involving sources of transmission in Bahrain are required to enhance control measures for HCV infection.