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The emergence and spread of multidrug-resistant (MDR) pathogenic bacteria is a clinical problem that requires novel anti-infective agents. Targeting pathogenic biofilms is considered a promising st...

The emergence and spread of multidrug-resistant (MDR) pathogenic bacteria is a clinical problem that requires novel anti-infective agents. Targeting pathogenic biofilms is considered a promising strategy to control bacterial infections. In this study, bioactive extracts of

This study aimed to investigate the occurrence of biofilm-forming extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and to evaluate their antibiotic resistance behaviour and transferability of the plasmid-encoded blaCTX-M gene in biofilm. ESBL production was confirmed using the combined disc test and Etest. Amplification of blaCTX-M was performed by PCR. Antibiotic susceptibility was evaluated using the disc diffusion assay and broth dilution method. Transfer of blaCTX-M in planktonic and biofilm state was performed by broth mating and filter mating experiments, respectively. Among 110 enteric bacteria, 24 (21.8%) isolates belonging to Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae were found to produce ESBL and formed varying levels of biofilm in vitro. Presence of blaCTX-M was detected in 18 (75%) ESBL-producing isolates. A many fold increase in resistance to antibiotics was observed in biofilm. Among ESBL-producers, seven isolates could transfer the blaCTX-M gene by conjugation, with transfer frequencies ranging from 2.22×10(-4) to 7.14×10(-2) transconjugants/recipient cell in the planktonic state and from 3.04×10(-3) to 9.15×10(-1) in biofilm. The transfer frequency of blaCTX-M was significantly higher in biofilm compared with the planktonic state, and co-transfer of ciprofloxacin resistance was also detected in five isolates. This study demonstrates that biofilm-forming ESBL-producing enteric bacteria with a greater transfer frequency of resistance genes will lead to frequent dissemination of β-lactam and fluoroquinolone resistance genes in environmental settings. The emergence and spread of such multidrug resistance is a serious threat to animal and public health.

This study aimed to evaluate the incidence of ciprofloxacin-resistant extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and clinical sources. Enteric bacteria, mainly Escherichia coli, were isolated from clinical sources (urinary tract and gastrointestinal tract infections; 80 isolates) and hospital wastewater (103 isolates). The antibiotic resistance profile and ESBL production of the isolates were investigated by disc diffusion assay and combined disc diffusion test, respectively. Plasmid profiling was performed by agarose gel electrophoresis, and elimination of resistance markers was performed by a plasmid curing experiment. Antibiotic susceptibility testing revealed a high incidence of β-lactam resistance, being highest to ampicillin (88.0%) followed by amoxicillin, ceftriaxone, cefpodoxime, cefotaxime, aztreonam, cefepime and ceftazidime. Among the non-β-lactam antibiotics, the highest resistance was recorded to nalidixic acid (85.7%). Moreover, 50.8% of enteric bacteria showed resistance to ciprofloxacin. Among 183 total enteric bacteria, 150 (82.0%) exhibited multidrug resistance. ESBL production was detected in 78 isolates (42.6%). A significantly higher incidence of ciprofloxacin resistance was observed among ESBL-producing enteric bacteria both in clinical (P=0.0015) and environmental isolates (P=0.012), clearly demonstrating a close association between ESBL production and ciprofloxacin resistance. Plasmid profiling of selected ESBL-positive strains indicated the presence of one or more plasmids of varying sizes. Plasmid curing resulted in loss of ciprofloxacin and cefotaxime resistance markers simultaneously from selected ESBL-positive isolates, indicating the close relationship of these markers. This study revealed a common occurrence of ciprofloxacin-resistant ESBL-producing enteric bacteria both in hospital wastewater and clinical sources, indicating a potential public health threat.

The worldwide emergence of resistant bacteria to multiple antimicrobial drugs is one of the greatest hurdles to chemotherapy. Multidrug resistance (MDR) is the capability of pathogenic bacteria to survive lethal doses of antimicrobial drugs. One of the underlying mechanisms of survival under stressful conditions is the extrusion of drugs through membrane-embedded efflux proteins. These ubiquitous resistance elements, which confer resistance or cross resistance to multiple drugs, are considered MDR efflux transporters. Consequently, efflux pump inhibitors (EPIs) from various natural and synthetic sources have been developed to increase the therapeutic armamentarium for combating bacterial resistance and restoring the antibiotic activity. Owing to less toxicity issues than chemical-based EPIs, plant-based EPIs are gaining much importance, but none are yet undergoing clinical trials. In this review, we will introduce the concept of efflux pumps and their diversity and then provide a comprehensive understanding of efflux pump inhibitors from both plant and chemical sources, their mode of action and the recent advances in their development.

The widespread occurrence of extended spectrum β-lactamases (ESβLs) producing enteric bacteria and their co-resistance with flouroquinolones has impaired the current antimicrobial therapy. This has prompted the search for new alternatives through synergistic approaches with herbal extracts. In this study Carum copticum (seeds) was extracted first in methanol and then subsequently extracted in different organic solvents. MIC of plant extracts, ciprofloxacin and thymol was determined by broth micro-dilution method using TTC. Synergism between plant extracts and ciprofloxacin was assayed by the checkerboard method. Chemical constituents of active extracts were analyzed by GC-MS. Methanolic, hexane and ether extract of Carum copticum exhibited significant antibacterial activity with MIC values ranged from 0.25 mg/ml to 2.0 mg/ml. Synergy analysis between Carum copticum extracts and ciprofloxacin combinations revealed FIC index in the range of 0.093–0.25. About 81% ciprofloxacin resistant ESβL producing enteric bacteria were re-sensitized in the presence of 15.6–250 μg/ml of methanolic extract of Carum copticum. Moreover, ciprofloxacin showed 8 to 64 folds reduction in MIC in presence of 250 and 500 μg/ml of hexane extract. Whereas, 4–32 folds reduction in MIC of ciprofloxacin was achieved in the presence of 31.25 and 62.5 μg/ml of ether extract, indicating synergistic enhancement of drug activity. The chemical analysis of hexane and ether extracts by GC-MS revealed the common occurrence of one or more phenolic hydroxyl at different locations on benzene ring. This study demonstrated the potential use of herbal extract of Carum copticum in combination therapy against ESβL producing bacteria. Keywords: ESβL producing enteric bacteria, Carum copticum, Plant extracts, Synergy, Ciprofloxacin, GC/MS

The ecological fitness of soil- and root-associated bacterial communities is a key element for soil fertility and plant health as well as plant stress tolerance. Genetic variability in bacterial populations is maintained through mutation and gene acquisition. Horizontal gene transfer (HGT) is accomplished by conjugation, transformation, and transduction both in vitro and under natural conditions. Mobile genetic elements (MGEs) play a significant role in gene dissemination in bacterial communities and increase their adaptability, survival, and ability to colonize different environmental niches. In this context, bacterial conjugative plasmids encoding resistance genes, degradative genes, and tolerance to stress conditions are of much significance. The biofilm mode of bacterial growth further enhances gene exchange and increase the fitness and competitiveness of bacteria. Microcosm studies reveal a number of factors influencing the HGT process in soil. Considering the importance of HGT, a better understanding of genetic processes in the rhizosphere will further help in effective exploitation of naturally engineered bacteria for sustainable agriculture.

Medicinal plants and plant-derived bioactive compounds are well known for their contribution to primary health care as a source novel drug discovery for various ailments. Emergence and spread of microbial drug resistance due to various mechanisms has impacted the efficacy of almost all old and new antibacterial drugs. The biofilm mode of microbial growth has significantly increased the survival strategies and resistance levels of microbes to drugs, making the treatment of infections more difficult. Currently, efforts are going on to develop novel strategies including targeting biofilms to treat infections. Various natural products are known to inhibit biofilm formation or preformed biofilms. In recent years medicinal plants and phytocompounds were reported with promising antibiofilm activity in vitro from different parts of the world. In this chapter we have reviewed the current literature on antibiofilm agents derived from medicinal plants and/or plant-derived compounds. Plant extracts and phytocompounds of various classes have been found effective against bacterial or fungal biofilms, with some compounds showing activity against both. Such compounds are expected to be effective against mixed biofilms. Interestingly, certain quorum-sensing inhibiting plant extracts or compounds can also inhibit biofilms made by bacteria such as Pseudomonas aeruginosa. The majority of the antibiofilm phytocompounds identified so far have been tested in vitro; however, only a few compounds have been reported effective under in vivo condition. This could be due to the lack of access of the investigators to suitable animal models for different diseases to assess the therapeutic efficacy of these antibiofilm agents. The results of this chapter indicated that the phytocompounds may be effective alone or in combination with antibiotics, as in the treatment of systemic infection. However, further investigation on their mode of action and in vivo efficacy are prerequisites to obtain broad-spectrum antifungal agents of clinical value.

This paper seeks to analyse the relationship between the women’s opinion for the extent of employment of their income in different heads of family and its overall effect on family status of Kota city. This analysis of women participants’ opinion of Kota city for the factors of family which are nourished by their income are Financial Position and Status, Societal Status and Position, Living Standard and Statue, Education of Children, Family and Personal Health Security, Quality of life and Risk taking capabilities. Distribution of women participants’ opinion for application of their salaries in different expenditure heads of family are: in constructing home, in buying cars and automobiles, in education fees, in Insurance / Family Security, in Recreation and Leisure time, in Saving and Deposits / Investments, in Routine Expenses, in Medical and Health Issues, and in Paying Taxes. Their opinion might be influenced by the age group, educational qualification and current sector of their job. It has been an empirical study involving a questionnaire collected from 450 working women respondents working in Kota city, Rajasthan. A deep analysis of the findings will be discussed in this paper.