Emerging antibiotic resistance in bacteria with special reference to India

Antimicrobial Resistance Surveillance in Human Pathogens in Ahmedabad: A One-Year Prospective Study

Antimicrobial resistance (AMR) is an escalating global concern, particularly in developing countries like India. A 1-year prospective study was conducted on AMR in human pathogens from Ahmedabad, India. The study aimed to generate an evidence-based database on the AMR profile of pathogens in this region. The study analysed 2204 organisms isolated from various clinical specimens. WHONET software, a specialized tool for AMR data management and interpretation, was used for data management and analysis. The most frequently isolated pathogens were Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. These pathogens demonstrated varying resistance rates to different antibiotics. E. coli shows a high prevalence of MDR (57%), with 22% indicating possible XDR and 13% showing possible PDR. K. pneumoniae showed even higher rates of MDR (80%), with 57% indicating possible XDR and 54% possible PDR. S. aureus showed MDR in 51% of the isolates, with 11% showing possible XDR and 1% showing possible PDR. The study also identified some priority pathogens according to the World Health Organization (WHO) criteria based on their resistance to specific antibiotics. The study highlighted the significant prevalence of AMR, particularly MDR, among human pathogens in Ahmedabad, emphasizing the need for effective strategies to combat AMR in clinical settings and public health policies. The study has significant implications for understanding the epidemiology and transmission of AMR in this region, as well as for informing the development of guidelines and interventions for rational antibiotic use and infection control.

Antimicrobial and antioxidant study of combined essential oils of Anethum Sowa Kurz. and Trachyspermum ammi (L.) along with quality determination, comparative histo-anatomical features, GC‒MS and HPTLC chemometrics

Spices played crucial and variable roles in traditions, culture, history, religious ceremonials and festivals along with fetching food flavor and microbial protection globally due to presence of structurally unique and multi-natured chemotypes. Their existence in dishes portrayed key roles in improving shelf life by regulating spoilage of cuisine with different synergistic mechanism. Histo-anatomically (A) sowa exhibited distinguished cellular attributes which created remarkable differences with T. ammi. HPTLC chemometrics of both fruits revealed several peaks for active metabolomics with unique isocratic combination of menstruum. GC-MS study of hydro-distillate exhibited presence of monoterpenic cyclic and aromatic hydrocarbons, alcoholic and ketonic groups along with phenolic derivative that covers majorly 90% of total metabolites. Combined essential oils (EOs 1 + 2) of both fruits showed excellent antimicrobial activity against various clinical pathogenic strains such as K. pneumoniae at 10 µL/mL, S. aureus at 2.5 µL/mL, E. coli and E. faecalis at 1.25 µL/mL, and MRSA and Bcereus at 0.625 µL/mL and (C) albicans at 0.312 µL/mL as the MIC. The antioxidant study of (EOs 1 + 2) with maximum inhibition percentage to DPPH assay was 84.02 ± 1.05 at 100 µg/mL, and minimal inhibition was 72.31 ± 0.63 at 5 µg/mL with IC50 value 4.69 ± 0.22 µg/mL, while ABTS assay extreme was 79.15 ± 2.14 µg/mL and minimal was 67 ± 1.34 with the IC50 value of 18.37 ± 0.15 µg/mL, in superoxide assay uppermost inhibition was 81.03 ± 0.27 µg/mL and lowest was at 65.16 ± 3.15 with the IC50 value 16.46 ± 0.54, and H2O2 radical scavenging activity, predominant value was 78.01 ± 0.47 and least was 64.1 ± 2.01 with IC50 15.58 ± 0.34. These comparative key diagnostic features and synergistic effect of multicomponent natural antimicrobials will provide profound intellect of ancient utility and further scientists to explore their multiple mechanistic modality and application in food and beverages industry.

Prevalence and Antibiogram of Escherichia coli Isolated from Children Under Five Years of Age Presented with Acute Diarrhoea: Cross Sectional Study from a Tertiary Care Centre in South India

Aim:

The study aimed to analyze the prevalence and antibiogram of E. coli isolated from stool sample cultures collected from children below five years of age who were presented with acute diarrhoea in a tertiary care centre.

Background:

Multidrug-resistant strains of diarrheagenic E. coliremain a major public health concern for greater morbidity and mortality. Antibiotic resistance and susceptibility patterns of E. coli were found to vary with geographical location.

Objective:

To determine the prevalence and antibiogram of E. coli isolated from cultures of diarrhoea stool samples collected from children below five years of age from laboratory records.

Methods:

A cross-sectional study was designed to analyze the report on stool culture of children (aged below five years) presented with acute diarrhea during the period between 2017 and 2020. The prevalence of E. coli and its antibiogram were analyzed. The data were subjected to statis-tical analysis.

Results:

A total of 245 diarrhoea stool samples results were analyzed. E. coli was confirmed in 176 samples (72%). More number of isolates (51/176, 28.9%) were found in children below one year of age with male dominance. Amoxicillin resistance was found in all the E. coli strains isolated with no significant difference (p=0.2233) between genders and age groups below and above one year. A significant difference (p=0.0001) was found between male and female chil-dren of age below and above one year for cefotaxime and ciprofloxacin resistance. Polymyxin B (72%) followed by imipenem (69%) sensitivity was exhibited by the isolated E. coli strains.

Conclusion:

E. coli isolates were more sensitive to polymyxin B and imipenem while they were most resistant to amoxicillin. Effective antibiotic treatment strategies should be developed to control E. coli infections in children.

Phenotypic diagnosis and genotypic identification of Bacillus cereus causing subclinical mastitis in cows

Background and Aims

Bovine mastitis is a disease that affects dairy cows and impacts the global dairy industry. Bacillus spp. can infect the mammary gland during lactation, intramammary treatment, or dry cow therapy. This study aimed to isolate and identify Bacillus spp. in raw milk samples from cows with subclinical mastitis from dairy farms in Beheira, Giza, Alexandria, and Menoufia Governorate, Egypt. We also investigated their antibiotic sensitivity and detected the enterotoxigenic and antibiotic resistance genes.

Materials and Methods

A total of 262 milk samples (15-20 ml each) were examined microscopically, biochemically, and phenotypically. A polymerase chain reaction was used for genotypic identification and detecting antibiotic-resistance and enterotoxigenic genes. Antibiotic sensitivity was tested using the agar well diffusion test.

Results

Bacillus cereus was identified in 47.7% of samples. Nhe and hblD enterotoxin genes were found in 93.64% (103/110) and 91.82% (101/110) of the samples, respectively. Tetracycline and β-lactam antibiotic-resistance genes were present in 0% (0/110) and 98.18% (108/110), respectively, of the samples. All isolates were resistant to cefepime, cefixime, and oxacillin, while they were susceptible to amoxicillin-clavulanic, chloramphenicol, ampicillin/sulbactam, and levofloxacin.

Conclusion

These results highlight the need to promote awareness regarding B. cereus, the most common pathogen causing mastitis in Egyptian dairy cows. We also emphasized that antibiotic misuse during mastitis is a potential public health threat.

Differences in beta-lactam and penicillin allergy: Beyond the West and focusing on Asia-Pacific

Beta-lactam (BL) antibiotic "allergy" labels are common, but often overdiagnosed. Although much research has been focused on the BL allergy and the delabelling process in the West, studies from other parts of the world remain sparse. This review outlines the contrasting global epidemiology, shifting clinical practices and disparities of BL allergy in the Asia-Pacific region compared with the West. Innovative strategies to overcome barriers in BL allergy workup are discussed and potential directions for future research and service development are also proposed.

Improved management can be achieved by introducing additional parameters in the syndromic diagnosis of nonviral sexually transmitted infections at low-resource settings

BACKGROUND

The syndromic approach is a simple and affordable strategy for the management of sexually transmitted infections in countries with low-resource settings. However, because of the lack of specificity and accuracy, the risk of overuse and misuse of antibiotics is very high. Here, we proposed a more specific and accurate algorithm compared with the current algorithm used for syndromic case management of 3 common sexually transmitted pathogens and compared its precision with laboratory-based tests.

OBJECTIVE

This study aimed to report a comparative account of the accuracy of existing syndromic case management guidelines followed in mainstream hospitals, for taking care of patients with nonviral sexually transmitted infections, concerning an approach involving an alternative algorithm formulated in our laboratory followed by polymerase chain reaction testing.

STUDY DESIGN

This was an observational study that compared the data between 2 categories based on diagnostics accuracy and treatment. In category I, symptoms of infection were scored on the basis of the existing National AIDS Control Organization and National AIDS Control Programme guidelines, and patients were treated before testing by polymerase chain reaction. In category II, patients were recruited on the basis of the National AIDS Control Organization and National AIDS Control Programme guidelines with additional alternative syndromic case management parameters. All samples were tested by polymerase chain reaction for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis and clinically correlated before giving the treatment.

RESULTS

In category I, among 646 women with symptomatic infection, only 46 (7.82%) tested positive by polymerase chain reaction assay for at least 1 of the pathogens, and 600 (92.87%) tested negative for infection by any of the 3 pathogens. The total estimated percentages of the overuse and misuse of antibiotics were 92.87% and 8.69%, respectively. Correct and complete treatment based on laboratory outcome compared with National AIDS Control Programme guidelines was 42 of 46 (91.30%). The estimated overuse of azithromycin and cefixime (Gray Kit) was 29.69%, the estimated overuse of a combination of doxycycline, cefixime, and metronidazole (Yellow Kit) was 29.87%, and the estimated overuse of a combination of doxycycline, cefixime, metronidazole, and azithromycin (Gray with Yellow Kit) was 11.45%. In category II, wherein patients were treated using an alternative syndromic approach and polymerase chain reaction diagnostics, 243 of 319 patients (76.15%) were infected with either of the pathogens (Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis), whereas 76 of 319 patients (23.82%) were negative for any of the 3 pathogens. Among 243 patients with infection, 99 of 243 (40.74%) were infected with a single pathogen, whereas 144 of 243 (59.20%) were coinfected. Of 144 coinfected patients, the percentage of Chlamydia trachomatis + Neisseria gonorrhoeae infection was the highest (51.38%), followed by coinfection with all 3 pathogens (30%). Coinfection with Chlamydia trachomatis + Trichomonas vaginalis was 9.72%, and coinfection with Neisseria gonorrhoeae + Trichomonas vaginalis was 9.03%. The estimated overuse of antibiotics was found to be 23.82% only.

CONCLUSION

The proposed alternative strategies of syndromic case management can reduce the percentage of misuse and overuse of antibiotics from 92.87% to 23.82%. Moreover, syndromic case management alone was insufficient for disease management.

Antimicrobial prescription patterns among oral implantologists of Kerala, India: A cross-sectional survey

Background and Objectives:

Antimicrobial resistance is a grave public health concern, and it is important to optimize the use of antimicrobials in dental surgeries. Antimicrobial prescriptions in dental implant placements are often empiric and not guided by consensus or specific guidelines. The aim of this study was to elucidate antibiotic prescribing patterns among oral implantologists. The objectives were to identify the frequency of antimicrobial usage and preferences regarding the perioperative timing of prescriptions, type of antibiotic, dosage, and duration in different implant placement scenarios.

Subjects and Methods:

An anonymized web-based survey was carried out. Participants were drawn from the lists of oral implantologists from all local branches of the Indian Dental Association in the state of Kerala, India, until the required sample size was met. Responses were recorded using an Internet-based validated questionnaire sent via e-mail to the participants. The questionnaire contained five sections with both open-ended and closed-ended questions.

Results:

Among the 93 participants, 59% of the dental implantologists preferred 0.2% povidone-iodine as a preprocedural mouth rinse in the backdrop of the COVID-19 pandemic, and 68% prescribed 0.12%–0.2% chlorhexidine as the postoperative mouth rinse. The majority of the participants (73%) routinely prescribed systemic antibiotics perioperatively during implant placement surgery. Interestingly, while none of the participants preferred a solely preoperative regimen, 92.4% of the dentists in our survey prescribed both pre- and postoperative antibiotics. Antibiotics of choice as the preoperative agents were amoxicillin and amoxicillin plus clavulanic acid. The most preferred postoperative agent was amoxicillin plus clavulanic acid. The popularly reported rationale behind a preoperative antibiotic was to decrease or eliminate local or systemic infections (79%), and the majority of the participants (60%) prescribed postoperative antibiotics to prevent postoperative infection.

Conclusions:

Systemic antibiotic prescriptions in implant placement surgery are not based on currently available evidence. Most oral implantologists who participated in the survey prescribed systemic antibiotics to prevent perioperative infection, even in simple and straightforward implant placements. Specific guidelines need to be generated in complex implant placement situations and implant placement in medically compromised patients to prevent excessive prescriptions.

A quest to the therapeutic arsenal: Novel strategies to combat multidrug-resistant bacteria

The increasing resistance of the disease-causing pathogens to antimicrobial drugs is a public health concern and a socio-economic burden. The emergence of multi-drug resistant strains has made it harder to treat and combat infectious diseases with available conventional antibiotics. There are currently few effective therapeutic regimens for the successful prevention of infections caused by drug-resistant microbes. The various alternative strategies used in the recent past to decrease and limit antibiotic resistance in pathogens include bacteriophages, vaccines, anti-biofilm peptides, and antimicrobial peptides. However, in this review, we focus on the novel and robust molecular approach of antisense RNA (asRNA) technology and the clustered regulatory interspaced short palindromic repeat (CRISPR)-based antibiotic therapy, which can be exploited to selectively eradicate the drug-resistant bacterial strain in a sequence-specific fashion establishing opportunities in the treatment of multi-drug resistant related infections.

Emergence of Third Generation Cephalosporin Resistant Escherichia coli in Infants: Retrospective Study from a Tertiary Care Hospital in South India

Aim:

This study was aimed to evaluate the emergence of third generation cephalosporin resistant Escherichia coli isolated from the culture of various biological fluids of infants in a tertiary care hospital.

Background:

Resistance to commonly used antibiotics is consistently increasing during the last decades and it was found varying with time and geographical location.

Objectives:

To determine the prevalence of third generation cephalosporin sensitivity pattern of E. coli isolated from urine, stool, and throat swab culture from laboratory records.

Methods:

The retrospective study included the laboratory report of antibiotic sensitivity conducted on infants specimens during the period of 2 years. Third generation cephalosporin sensitivity patterns of E. coli isolated from urine, stool, and throat swab culture were collected and data were statistically analyzed.

Results:

Reports of 351 samples with positive E. coli were included in the study. More samples were analyzed from infants above 6 months of age with female dominance (184/351). Among the specimens tested, urine samples were highest 128/351 (35.0%). Cephalosporin resistant strain was found in 243/351 samples (69.2%) (p=0.0463) with 218/243 (89.7%) isolated from infants above 6 months of age and 25/243 (10.2%) were from infants below 6 months of age (p=0.038). The frequency of cephalosporin resistant E. coli in urine specimens of male and female infants was significant (p=0.0001).

Conclusion:

Third generation cephalosporin resistant E. coli strain was found in 69.2% of isolates and more in urine samples from female infants above 6 months of age. The clinicians should consider the emergence of cephalosporin resistant E. coli while selecting antibiotics as empirical treatment.

Ultrasonic Nanoemulsification of Cuminum cyminum Essential Oil and Its Applications in Medicine

Background and Study

Cumin seed oil (extracted from Cuminum cyminum) has many applications but conclusive evidence of its therapeutic uses has not been presented. This study has explored the anticancer and antibacterial properties of the seed oil.

Methods

The cumin nanoemulsion was prepared with Tween 80 non-ionic surfactant employing ultra-sonication technology. The anticancer activity of the nanoscale-based emulsion was evaluated through cell viability (MTT), antiproliferation evaluation through clonogenic assay, and apoptosis through Annexin V-FITC assay. Agar well diffusion was used to study the antimicrobial activity, and this was supported by membrane integrity analysis.

Results

A thorough study of process parameters, aimed at obtaining the optimal surface concentration and emulsification time, was completed. GC-MS data indicated cumaldehyde as a major component. The resultant droplet diameter after a sonication time of 5 min was 10.4 ± 0.5 nm. MTT assay revealed the IC₅₀ value at 1.5 µL/mL and the early induction of apoptosis was evident. Tongue carcinoma cell line treated with cumin nanoemulsion presented a diminished colony formation. The nanoemulsion exhibited significant antibacterial activity against S. aureus. A significant cytoplasmic leakage was observed on treatment with cumin nanoemulsion. The consequences of the analysis projected cumin as a potential component for cancer therapy.

Conclusion

This study provides definitive evidence for cumin essential oil nanoemulsion as a legitimate plant-based medicine that can bypass the drawbacks of the present aggressive treatment of cancer, can overcome the antimicrobial resistance, and can also meet all prerequisites.

Longitudinal comparative trial of antibiotic cycling and mixing on emergence of gram negative bacterial resistance in a pediatric medical intensive care unit

PURPOSE

To compare antibiotic mixing vs. cycling with respect to acquisition of resistance and PICU mortality.

MATERIALS AND METHODS

Children between >1 month to 12 years admitted to a medical PICU were enrolled over three phases (baseline, mixing and cycling) with washout interval of 3 months following each antibiotic strategy. Following a baseline phase, empiric gram negative antibiotic protocol for suspected HCAI, was sequentially subjected to mixing and cycling using Latin Square methodology. Surveillance cultures were taken at admission, 48 h, weekly thereafter and within 2 days of PICU discharge. Acquisition of resistance and PICU mortality were primary and secondary outcomes respectively.

RESULTS

778 children were enrolled; 99 baseline, 146 mixing, 362 cycling, and 171 during two washout phases. Proportion of children with acquired resistance at baseline (56.6%) was significantly higher than mixing (22.6%) and cycling (18.51%) (p < .0001). Adjusted hazards of acquired resistance (HR:0.82; 95% CI: 0.53-1.25, p = .352), and PICU mortality (RR1.07; 95% CI: 0.71-1.60, p = .72) were similar in cycling and mixing strategies.

CONCLUSIONS

Acquisition of resistance was significantly lower in both mixing and cycling as compared to baseline phase. Both were similar with respect to risk of antibiotic resistance as well as incidence of HCAI and PICU mortality.

Extensively drug-resistant and pandrug-resistant Gram-negative bacteria in a tertiary-care hospital in Eastern India: A 4-year retrospective study

OBJECTIVES

Bacteria resistant to different classes of antimicrobial agents are a major threat to humanity and risk leading the world towards the return of the pre-antimicrobial era. This study was undertaken to detect the incidence of extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria in a tertiary-care hospital in Bhubaneswar, Odisha, India.

METHODS

Positive bacterial cultures from different clinical samples were identified using a VITEK^®2 compact system and the antimicrobial susceptibility profile of different Gram-negative bacteria was analysed.

RESULTS

A total of 2489 clinical samples were collected and processed for culture during the period January 2013 to April 2017. Of 1103 pure bacterial cultures, 690 (62.6%) were Gram-negative bacteria. The antimicrobial susceptibility profile of Gram-negative bacterial strains revealed that 41.3% (n=285) were XDR and 8.1% (n=56) were PDR. Rates of colistin and tigecycline resistance were 16% and 51.9%, respectively.

CONCLUSION

This situation demands regular surveillance of antimicrobial resistance of Gram-negative bacteria and implementation of an efficient infection control programme.

Dynamics of antibiotic resistance with special reference to Shiga toxin-producing Escherichia coli infections

The discovery of antibiotics was paralleled by the evolution of antibiotic resistance which is probably the best example of contemporary evolution in action. The selection pressure, imposed by indiscriminate use of antibiotics, has changed the scale, mode and tempo of antibiotic resistance evolution. The presence of multidrug resistance, wide range of adaptability features and the infectivity make antibiotic resistance of Shiga toxin-producing Escherichia coli (STEC) more dangerous. The characterization, prevalence and the virulence factors of STEC have been profusely reported, whereas, the antibiotic resistance has been largely ignored because the antibiotic use in STEC infections is controversial. Thus, the current review has focussed on the source, evolution, persistence, mechanism, dissemination and control of antibiotic resistance viz-a-viz the STEC infections. The resistance development occurs by the inactivation of antibiotics, regulating the membrane permeability, modification of natural antibiotic targets or the use of efflux pumps against antibiotics. And, the dissemination of resistance genes occurs vertically by DNA replication and horizontally by conjugation, transduction and transformation. The prevention of development and dissemination of antibiotic resistance needs international public health bodies to rationalize the antibiotic use, prevent the flux of antibiotics into the environment, develop the rapid diagnostics tests, undertake proper surveillance of antibiotic resistance, promote the research on antibiotic resistance prevention, promote the research and development of novel alternative antibiotics, and encourage the widespread social awareness campaigns against the inappropriate antibiotic usage.

Anticancer and antibacterial effects of Iranian viper (Vipera latifii) venom; an in-vitro study

Viper venom contains antibacterial and cytotoxic components. The aim of this study was to identify and evaluate the antimicrobial and cytotoxic properties of the crude venom of Vipera latifii (V. latifii). Lyophilized venom of V. latifii was quantified by Bradford method and its antibacterial activity (6.25-400 μg/ml) was assessed using the MTT, MIC, Disc diffusion, and Well diffusion assays. Also, its cytotoxic activity was investigated using MTT reduction, Neutral uptake, and Comet assay on human liver cancer (HepG2) cell line. Crude venom showed antibacterial effects against Bacillus subtilis and Staphylococcus aureus, but was not effective on Escherichia coli. Also, the crude venom showed apoptotic and necrotic effects on human liver cancer cells. The venom of V. latifii can inhibit the growth of bacteria and cancer cells. These findings suggest that this may be a potential source of molecules with antibacterial and anticancer characteristics.

Antimicrobial Resistance: Its Surveillance, Impact, and Alternative Management Strategies in Dairy Animals

Antimicrobial resistance (AMR), one among the most common priority areas identified by both national and international agencies, is mushrooming as a silent pandemic. The advancement in public health care through introduction of antibiotics against infectious agents is now being threatened by global development of multidrug-resistant strains. These strains are product of both continuous evolution and un-checked antimicrobial usage (AMU). Though antibiotic application in livestock has largely contributed toward health and productivity, it has also played significant role in evolution of resistant strains. Although, a significant emphasis has been given to AMR in humans, trends in animals, on other hand, are not much emphasized. Dairy farming involves surplus use of antibiotics as prophylactic and growth promoting agents. This non-therapeutic application of antibiotics, their dosage, and withdrawal period needs to be re-evaluated and rationally defined. A dairy animal also poses a serious risk of transmission of resistant strains to humans and environment. Outlining the scope of the problem is necessary for formulating and monitoring an active response to AMR. Effective and commendably connected surveillance programs at multidisciplinary level can contribute to better understand and minimize the emergence of resistance. Besides, it requires a renewed emphasis on investments into research for finding alternate, safe, cost effective, and innovative strategies, parallel to discovery of new antibiotics. Nevertheless, numerous direct or indirect novel approaches based on host-microbial interaction and molecular mechanisms of pathogens are also being developed and corroborated by researchers to combat the threat of resistance. This review places a concerted effort to club the current outline of AMU and AMR in dairy animals; ongoing global surveillance and monitoring programs; its impact at animal human interface; and strategies for combating resistance with an extensive overview on possible alternates to current day antibiotics that could be implemented in livestock sector.

Association study of multiple antibiotic resistance and virulence: a strategy to assess the extent of risk posed by bacterial population in aquatic environment

The present study explored the association between multiple antibiotic resistance (MAR) index and virulence index to determine what percent of environmental antibiotic-resistant (eARB) bacteria could pose threat as potential pathogen. 16srRNA-based sequencing of 113 non-duplicate isolates identified majority of them to be gram negative belonging to Enterobacter, Pseudomonas, Aeromonas, Proteus, Acinetobacter, and Klebsiella. Statistical comparison of MAR indices of the abovementioned genera indicated differences in the median values among the groups (p < 0.001). Pair-wise multiple comparison by Dunn's method indicated significant difference in MAR indices (p < 0.05), based on which multiple antibiotic resistance phenotype could be ranked in the order Pseudomonas > Klebsiella = Acinetobacter > Proteus > Aeromonas > Enterobacter. Association between MAR index and virulence index revealed that 25% of isolates in the population under study posed high threat to human/animal or both; out of which 75% isolates belonged to genus Pseudomonas. Based on observations of comparative analysis of the six gram-negative genera, it could be concluded that Pseudomonas isolates from environment pose significantly high threat as potential pathogens while Enterobacter isolates posed no threat.

Antibacterial and antibiotic potentiating activities of tropical marine sponge extracts

Increasing prevalence of antibiotic resistance has led research to focus on discovering new antimicrobial agents derived from the marine biome. Although ample studies have investigated sponges for their bioactive metabolites with promising prospects in drug discovery, the potentiating effects of sponge extracts on antibiotics still remains to be expounded. The present study aimed to investigate the antibacterial capacity of seven tropical sponges collected from Mauritian waters and their modulatory effect in association with three conventional antibiotics namely chloramphenicol, ampicillin and tetracycline. Disc diffusion assay was used to determine the inhibition zone diameter (IZD) of the sponge total crude extracts (CE), hexane (HF), ethyl acetate (EAF) and aqueous (AF) fractions against nine standard bacterial isolates whereas broth microdilution method was used to determine their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and antibiotic potentiating activity of the most active sponge extract. MIC values of the sponge extracts ranged from 0.039 to 1.25mg/mL. Extracts from Neopetrosia exigua rich in beta-sitosterol and cholesterol displayed the widest activity spectrum against the 9 tested bacterial isolates whilst the best antibacterial profile was observed by its EAF particularly against Staphylococcus aureus and Bacillus cereus with MIC and MBC values of 0.039mg/mL and 0.078mg/mL, respectively. The greatest antibiotic potentiating effect was obtained with the EAF of N. exigua (MIC/2) and ampicillin combination against S. aureus. These findings suggest that the antibacterial properties of the tested marine sponge extracts may provide an alternative and complementary strategy to manage bacterial infections.

Potential of combination therapy of endolysin MR-10 and minocycline in treating MRSA induced systemic and localized burn wound infections in mice

MRSA is the predominant pathogen responsible for fatal burn wound infection in patients. Antibiotic resistance and its ability to form biofilms on the surface of burn wounds limit the use of antibiotics to contain this pathogen. The results of present study have shown that single dose of combination therapy of endolysin MR-10 (50μg/s.c) and minocycline (50mg/kg/orally) resulted in 100% survival of group of mice with systemic MRSA infection. Maximum reduction in bacterial load in various organs was observed in the group that received combination therapy. In comparison to control, a significant reduction (p<0.01) of 4.82, 1.81, 1.51, 1.2 logs was observed in skin, blood, liver and spleen respectively, by 3rd day post infection. As a result of which, all organs became sterile thereby protecting mice from mortality. Histopathological analysis corroborated our findings showing no signs of inflammation and bacterial infection in the group that received combination therapy. Treatment of localized burn wound infection with combination therapy resulted in early resolution of infection followed by fast healing. The group that received combination therapy showed complete resolution of infection in less than 10days. Moreover, the skin samples obtained from animals treated with combination therapy showed no myeloperoxidase (MPO) activity on 10th day post treatment. In combination therapy group, ∼98% wound contraction was observed by 12th day followed by complete closure of wound within ∼14days. The histopathological analysis showed no signs of inflammation and infection. Collagen staining revealed early signs of re-epithelization of epidermis and signs of collagen regeneration in-group that received combination therapy. Hence, this study suggests that the combined therapy of endolysin MR-10 and minocycline is a better option in controlling burn wound infections.

Poor health knowledge and behaviour is a risk for the spread of antibiotic resistance: survey of higher secondary school students in Goa, India

AIMS

We assessed antibiotic knowledge and practice among youth in India, where antibiotics are widely available without prescription.

METHODS

Randomly selected school questionnaire survey representing four regions in Goa, India, with students ( n = 773) aged 16-17.

RESULTS

Most students (67%) were unaware of the problem of antibiotic resistance, with around half (49%) mistakenly thinking that bacteria cause cold or flu. Around one-fifth (19%) said they frequently self-medicate with antibiotics, 57% would discontinue antibiotics when symptoms alleviated and 24% stored unused antibiotics at home. Generalised linear mixed models (GLMM) showed that females consistently had poorer antibiotic knowledge than males. Especially notable were the higher odds in females for reporting incorrectly that antibiotics kill harmful viruses (odds ratio (OR) = 1.93; 99.5% confidence interval (CI) = 1.09-3.41) and for reporting incorrectly that antibiotics do not kill harmless bacteria (OR = 2.02; 99.5% CI = 1.16-3.51). Poor antibiotic practice was not clearly differentiated between males and females. In terms of poor antibiotic practice, one model showed notable results for educational stream: both arts and commerce students were more likely than science students to say they would discontinue antibiotics when symptoms alleviated and before the antibiotic course of treatment was finished (arts: OR = 2.76; 99.5% CI = 1.58-4.82 and commerce: OR = 1.79; 99.5% CI = 1.06-3.04).

CONCLUSION

Young adults in India had poor antibiotic knowledge and practice. Efforts to improve antibiotic health knowledge and safe practice are required to help prevent the spread of antibiotic resistance.

New Perspectives on the Use of Phytochemicals as an Emergent Strategy to Control Bacterial Infections Including Biofilms

The majority of current infectious diseases are almost untreatable by conventional antibiotic therapy given the advent of multidrug-resistant bacteria. The degree of severity and the persistence of infections are worsened when microorganisms form biofilms. Therefore, efforts are being applied to develop new drugs not as vulnerable as the current ones to bacterial resistance mechanisms, and also able to target bacteria in biofilms. Natural products, especially those obtained from plants, have proven to be outstanding compounds with unique properties, making them perfect candidates for these much-needed therapeutics. This review presents the current knowledge on the potentialities of plant products as antibiotic adjuvants to restore the therapeutic activity of drugs. Further, the difficulties associated with the use of the existing antibiotics in the treatment of biofilm-related infections are described. To counteract the biofilm resistance problems, innovative strategies are suggested based on literature data. Among the proposed strategies, the use of phytochemicals to inhibit or eradicate biofilms is highlighted. An overview on the use of phytochemicals to interfere with bacterial quorum sensing (QS) signaling pathways and underlying phenotypes is provided. The use of phytochemicals as chelating agents and efflux pump inhibitors is also reviewed.

Bacteriological spectrum and antimicrobial susceptibility pattern of neonatal septicaemia in a tertiary care hospital of North India

BACKGROUND

Neonatal septicaemia is a clinical entity that is characterised by systemic signs and symptoms of infection and accompanied by bacteraemia in first 4 weeks of life and is one of the four leading causes of neonatal mortality and morbidity in India.

AIM

To determine the bacterial spectrum and antimicrobial susceptibility pattern of neonatal septicaemia in a tertiary care hospital of North India.

MATERIALS AND METHODS

In this prospective observational study, 850 blood samples were collected and processed from clinically suspected neonates according to standard laboratory protocol. Antimicrobial susceptibility of the isolates was done by Kirby Bauer disc diffusion method according to Clinical and Laboratory Standard Institution (CLSI) recommendations.

RESULTS

Blood culture reports were positive in 322 (37.8%) cases. Early onset sepsis (EOS) was present in 61.41% and late onset sepsis (LOS) in 38.59% of cases. Gram-negative septicaemia (60.67%) was encountered more than Gram-positive (32.01%). Coagulase negative Staphylococci (17.43%) was the predominant isolate followed by, Klebsiella spp in 16.11% cases. Best overall sensitivity among Gram-negative isolates was to Colistin (89.94%), Imipenem (86.43%) and Meropenam (77.88%). Gram-positive isolates had good (97.15%) sensitivity to linezolid, (95.23%) vancomycin and (88.57%) Teicoplanin.

CONCLUSION

Gram-negative organisms are the leading cause of neonatal septicaemia with Klebsiella spp being commonest. Coagulase negative Staphylococci is the predominant isolate among Gram-positive organisms. Most of the isolates are resistant to common antibiotics.

Evaluation of antibacterial activity of Calotropis gigentica against Streptococcus mutans and Lactobacillus acidophilus: An in vitro comparative study

Background:

This study was conducted to evaluate in vitro antibacterial potential of ethanolic extract of Calotropis gigentica.

Materials and Methods:

The inhibitory effect of the ethanolic extract was tested against Streptococcus mutans and Lactobacilli casei by using disc diffusion method.

Results:

Ethanolic extract of Calotropis gigentica showed 16 mm and 14 mm of minimum inhibition zone at 1.25% concentration for S. mutans and lactobacilli, respectively.

Conclusion:

Calotropis gigentica was found to effective against S. mutans and lactobacilli.

Predictors of rational management of diarrhea in an endemic setting: observation from India

Background

Decades after the establishment of clear guidelines for management, mostly due to irrational approach, diarrhea is still a major concern in the developing world, including India. The scenario is even worse in urban slums owing to poor health-seeking and socio-environmental vulnerability. Determining the distribution of rational diarrhea management by practitioners and identification of its important predictors seemed urgent to minimize the potential for antibiotic resistance, diarrhea-related mortality and morbidity in these areas.

Methods

Between May 2011 and January 2012, 264 consenting, randomly selected qualified and non-qualified practitioners (including pharmacists) were interviewed in the slums of Kolkata, a populous city in eastern India, regarding their characteristics, diarrhea-related knowledge (overall and in six separate domains: signs/symptoms, occurrence/spread, management, prevention/control, cholera and ORS), prescribed antibiotics, intravenous fluid (IVF) and laboratory investigations. Rationality was established based on standard textbooks.

Results

Among participants, 53.03% had no medical qualifications, 6.06% were attached to Governmental hospitals, 19.32% had best knowledge regarding diarrhea. While treating diarrhea, 7.20%, 17.80% and 20.08% respectively advised antibiotics, IVF and laboratory tests rationally. Logistic regression revealed that qualified and Governmental-sector practitioners managed diarrhea more rationally. Having best diarrhea-related knowledge regarding signs/symptoms (OR=5.49, p value=0.020), occurrence/spread (OR=3.26, p value=0.035) and overall (OR=6.82, p value=0.006) were associated with rational antibiotic prescription. Rational IVF administration was associated with best knowledge regarding diarrheal signs/symptoms (OR=3.00, p value=0.017), occurrence/spread (OR=3.57, p value=0.004), prevention/control (OR=4.89, p value=0.037), ORS (OR=2.55, p value=0.029) and overall (OR=4.57, p value<0.001). Best overall (OR=2.68, p value=0.020) and cholera-related knowledge (OR=2.34, p value=0.019) were associated with rational laboratory testing strategy.

Conclusion

Diarrheal management practices were unsatisfactory in urban slums where practitioners’ knowledge was a strong predictor for rational management. Interventions targeting non-qualified, independent practitioners to improve their diarrhea-related knowledge seemed to be required urgently to ensure efficient management of diarrhea in these endemic settings.

In-vitro antimicrobial activity of marine actinobacteria against multidrug resistance Staphylococcus aureus

OBJECTIVE

To investigate the antibacterial activity of marine actinobacteria against multidrug resistance Staphylococcus aureus (MDRSA).

METHODS

Fifty one actinobacterial strains were isolated from salt pans soil, costal area in Kothapattanam, Ongole, Andhra Pradesh. Primary screening was done using cross-streak method against MDRSA. The bioactive compounds are extracted from efficient actinobacteria using solvent extraction. The antimicrobial activity of crude and solvent extracts was performed using Kirby-Bauer method. MIC for ethyl acetate extract was determined by modified agar well diffusion method. The potent actinobacteria are identified using Nonomura key, Shirling and Gottlieb 1966 with Bergey's manual of determinative bacteriology.

RESULTS

Among the fifty one isolates screened for antibacterial activity, SRB25 were found efficient against MDRSA. The ethyl acetate extracts showed high inhibition against test organism. MIC test was performed with the ethyl acetate extract against MDRSA and found to be 1 000 µg/mL. The isolated actinobacteria are identified as Streptomyces sp with the help of Nonomura key.

CONCLUSIONS

The current investigation reveals that the marine actinobacteria from salt pan environment can be able to produce new drug molecules against drug resistant microorganisms.

Household Animal and Human Medicine Use and Animal Husbandry Practices in Rural Bangladesh: Risk Factors for Emerging Zoonotic Disease and Antibiotic Resistance

Animal antimicrobial use and husbandry practices increase risk of emerging zoonotic disease and antibiotic resistance. We surveyed 700 households to elicit information on human and animal medicine use and husbandry practices. Households that owned livestock (n = 265/459, 57.7%) reported using animal treatments 630 times during the previous 6 months; 57.6% obtained medicines, including antibiotics, from drug sellers. Government animal healthcare providers were rarely visited (9.7%), and respondents more often sought animal health care from pharmacies and village doctors (70.6% and 11.9%, respectively), citing the latter two as less costly and more successful based on past performance. Animal husbandry practices that could promote the transmission of microbes from animals to humans included the following: the proximity of chickens to humans (50.1% of households reported that the chickens slept in the bedroom); the shared use of natural bodies of water for human and animal bathing (78.3%); the use of livestock waste as fertilizer (60.9%); and gender roles that dictate that females are the primary caretakers of poultry and children (62.8%). In the absence of an effective animal healthcare system, villagers must depend on informal healthcare providers for treatment of their animals. Suboptimal use of antimicrobials coupled with unhygienic animal husbandry practices is an important risk factor for emerging zoonotic disease and resistant pathogens.

Effects of the natural compounds embelin and piperine on the biofilm-producing property of Streptococcus mutans

We aimed to evaluate the effects of the natural compounds embelin and piperine on the biofilm-formation property of Streptococcus mutans. A total of 30 clinical isolates were identified as S. mutans and screened for biofilm formation using the microtiter plate method. The strongest biofilm producer (SM03) was used for identifying both minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC). We subsequently used this concentration against each of the strong biofilm producer isolates at A 492 < 0.5 optical density (OD). Of the 30 isolates screened for biofilm formation, 18 isolates showed strong biofilm formation, 09 isolates showed moderate formation, and 03 isolates showed poor/nonbiofilm formation. The MIC of embelin for the strongest biofilm producer (SM03) was 0.55 ± 0.02, whereas that of piperine was 0.33 ± 0.02. The MBIC of embelin was 0.0620 ± 0.03, whereas that of piperine was 0.0407 ± 0.03, which was lower than that of embelin. At OD492 < 0.5, the MBIC of both compounds significantly inhibited biofilm formation of all the 18 strong biofilm-forming isolates. The results of this study demonstrate a significant antibiofilm effect of the natural compounds embelin and piperine, which can contribute towards the development of a database for novel drug candidates for treating oral infections caused by S. mutans.

Phylogenetic distribution and prevalence of genes encoding class I Integrons and CTX-M-15 extended-spectrum β-lactamases in Escherichia coli isolates from healthy humans in Chandigarh, India

Escherichia coli is generally considered as a commensal inhabitant of gastrointestinal tract of humans and animals. The aim of this study was to gain insight on the distribution of phylotypes and presence of genes encoding integrons, extended β-lactamases and resistance to other antimicrobials in the commensal E. coli isolates from healthy adults in Chandigarh, India. PCR and DNA sequencing were used for phylogenetic classification, detections of integrase genes, gene cassettes within the integron and extended β-lactamases. The genetic structure of E. coli revealed a non-uniform distribution of isolates among the seven phylogenetic groups with significant representation of group A. Integron-encoded integrases were detected in 25 isolates with class 1 integron-encoded intI1 integrase being in the majority (22 isolates). The gene cassettes identified were those for trimethoprim, streptomycin, spectinomycin and streptothricin. The dfrA12-orfF-aadA2 was the most commonly found gene cassette in intI1 positive isolates. Phenotypic assay for screening the potential ESBL producers suggested 16 isolates to be ESBL producers. PCR detection using gene-specific primers showed that 15 out of these 16 ESBL-producing E. coli harboured the bla_CTX-M-15 gene. Furthermore, molecular studies helped in characterizing the genes responsible for tetracycline, chloramphenicol and sulphonamides resistance. Collectively, our study outlines the intra-species phylogenetic structure and highlights the prevalence of class 1 integron and bla_CTX-M-15 in commensal E. coli isolates of healthy adults in Chandigarh, India. Our findings further reinforce the relevance of commensal E. coli strains on the growing burden of antimicrobial resistance.

Characteristics of microbial drug resistance and its correlates in chronic diabetic foot ulcer infections

While virulence factors and the biofilm-forming capabilities of microbes are the key regulators of the wound healing process, the host immune response may also contribute in the events following wound closure or exacerbation of non-closure. We examined samples from diabetic and non-diabetic foot ulcers/wounds for microbial association and tested the microbes for their antibiotic susceptibility and ability to produce biofilms. A total of 1074 bacterial strains were obtained with staphylococci, Pseudomonas, Citrobacter and enterococci as major colonizers in diabetic samples. Though non-diabetic samples had a similar assemblage, the frequency of occurrence of different groups of bacteria was different. Gram-negative bacteria were found to be more prevalent in the diabetic wound environment while Gram-positive bacteria were predominant in non-diabetic ulcers. A higher frequency of monomicrobial infection was observed in samples from non-diabetic individuals when compared to samples from diabetic patients. The prevalence of different groups of bacteria varied when the samples were stratified according to age and sex of the individuals. Several multidrug-resistant strains were observed among the samples tested and most of these strains produced moderate to high levels of biofilms. The weakened immune response in diabetic individuals and synergism among pathogenic micro-organisms may be the critical factors that determine the delicate balance of the wound healing process.

Climatic factors and community - associated methicillin-resistant Staphylococcus aureus skin and soft-tissue infections - a time-series analysis study

Skin and soft tissue infections caused by Staphylococcus aureus (SA-SSTIs) including methicillin-resistant Staphylococcus aureus (MRSA) have experienced a significant surge all over the world. Changing climatic factors are affecting the global burden of dermatological infections and there is a lack of information on the association between climatic factors and MRSA infections. Therefore, association of temperature and relative humidity (RH) with occurrence of SA-SSTIs (n = 387) and also MRSA (n = 251) was monitored for 18 months in the outpatient clinic at a tertiary care hospital located in Bhubaneswar, Odisha, India. The Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing. Time-series analysis was used to investigate the potential association of climatic factors (weekly averages of maximum temperature, minimum temperature and RH) with weekly incidence of SA-SSTIs and MRSA infections. The analysis showed that a combination of weekly average maximum temperature above 33 °C coinciding with weekly average RH ranging between 55% and 78%, is most favorable for the occurrence of SA-SSTIs and MRSA and within these parameters, each unit increase in occurrence of MRSA was associated with increase in weekly average maximum temperature of 1.7 °C (p = 0.044) and weekly average RH increase of 10% (p = 0.097).

Strategies to combat antimicrobial resistance

The global burden of antimicrobial resistance is rising and is associated with increased morbidity and mortality in clinical and community setting. Spread of antibiotic resistance to different environmental niches and development of superbugs have further complicated the effective control strategies. International, national and local approaches have been advised for control and prevention of antimicrobial resistance. Rational use of antimicrobials, regulation on over-the-counter availability of antibiotics, improving hand hygiene and improving infection prevention and control are the major recommended approaches. Thorough understanding of resistance mechanism and innovation in new drugs and vaccines is the need. A multidisciplinary, collaborative, regulatory approach is demanded for combating antimicrobial resistance.

Antimicrobial resistance in India: A review

Antimicrobial resistance is an important concern for the public health authorities at global level. However, in developing countries like India, recent hospital and some community based data showed increase in burden of antimicrobial resistance. Research related to antimicrobial use, determinants and development of antimicrobial resistance, regional variation and interventional strategies according to the existing health care situation in each country is a big challenge. This paper discusses the situational analysis of antimicrobial resistance with respect to its problem, determinants and challenges ahead with strategies required in future to reduce the burden in India. Recent data from Google search, Medline and other sources were collected which was reviewed and analyzed by the authors. Hospital based studies showed higher and varied spectrum of resistance in different regions while there are limited number of community based studies at country level. There exists lacunae in the structure and functioning of public health care delivery system with regard to quantification of the problem and various determining factors related to antimicrobial resistance. There is an urgent need to develop and strengthen antimicrobial policy, standard treatment guidelines, national plan for containment of AMR and research related to public health aspects of AMR at community and hospital level in India.

Guidelines for prevention of hospital acquired infections

These guidelines, written for clinicians, contains evidence-based recommendations for the prevention of hospital acquired infections Hospital acquired infections are a major cause of mortality and morbidity and provide challenge to clinicians. Measures of infection control include identifying patients at risk of nosocomial infections, observing hand hygiene, following standard precautions to reduce transmission and strategies to reduce VAP, CR-BSI, CAUTI. Environmental factors and architectural lay out also need to be emphasized upon. Infection prevention in special subsets of patients - burns patients, include identifying sources of organism, identification of organisms, isolation if required, antibiotic prophylaxis to be used selectively, early removal of necrotic tissue, prevention of tetanus, early nutrition and surveillance. Immunodeficient and Transplant recipients are at a higher risk of opportunistic infections. The post tranplant timetable is divided into three time periods for determining risk of infections. Room ventilation, cleaning and decontamination, protective clothing with care regarding food requires special consideration. Monitoring and Surveillance are prioritized depending upon the needs. Designated infection control teams should supervise the process and help in collection and compilation of data. Antibiotic Stewardship Recommendations include constituting a team, close coordination between teams, audit, formulary restriction, de-escalation, optimizing dosing, active use of information technology among other measure. The recommendations in these guidelines are intended to support, and not replace, good clinical judgment. The recommendations are rated by a letter that indicates the strength of the recommendation and a Roman numeral that indicates the quality of evidence supporting the recommendation, so that readers can ascertain how best to apply the recommendations in their practice environments.

The multifaceted roles of antibiotics and antibiotic resistance in nature

Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic-resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic resistance in pathogens. In the natural milieu, antibiotics are often found to be present in sub-inhibitory concentrations acting as signaling molecules supporting the process of quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host-parasite interactions (e.g., phagocytosis, adherence to the target cell, and so on). The evolutionary and ecological aspects of antibiotics and antibiotic resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behavior of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and the genes that confer resistance to antibiotics in nature.

Comparative antibacterial activity of a novel semisynthetic antibiotic: etimicin sulphate and other aminoglycosides

Etimicin is a novel fourth generation semisynthetic aminoglycoside. It has good antimicrobial activity against both gram-positive and gram-negative bacterial infections and also against aminoglycoside resistant strains. In the present study, in vitro antibacterial activity of etimicin was determined by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time kill curve tests against type strains and 407 clinical isolates (obtained in a surveillance study), in comparison to other aminoglycosides. Test results revealed that etimicin has potential antimicrobial activity and MIC, MBC values for etimicin were low compared to other aminoglycosides. In MBC test etimicin has exhibited potential bactericidal effect ranging from 0.25 to 2 mg/L. The time kill-curve study further demonstrated the rapid, concentration dependent killing and comparative study showed etimicin to exhibit long and effective bactericidal activity over amikacin. The interesting fact is that most of the tested aminoglycoside resistant clinical isolates were susceptible to etimicin. In view of its potent in vitro antibacterial activity and efficacy profiles, it can be concluded that etimicin can be a potent injectable agent for the treatment of severe bacterial infections.

Detection and sequencing of plasmid encoded tetracycline resistance determinants (tetA and tetB) from food-borne Bacillus cereus isolates

OBJECTIVE

To investigate the detection and sequencing of plasmid encoded tetracycline resistance genes (tetA and tetB) from food-borne and standard strains of Bacillus cereus (B. cereus).

METHODS

A PCR was carried out to detect the tetracycline resistance genes (tetA and tetB) in food-borne B. cereus strains and the amplified products were sequenced.

RESULTS

The phenotypic resistance against tetracycline was observed in 39 of the 118 food-borne isolates and two reference strains (MTCC 430 and MTCC 1307) of B. cereus. Among the phenotypically resistant isolates, tetA was detected in 36 food-borne isolates and two reference strains (MTCC 430 and MTCC 1307), whereas, tetB was detected in 12 food-borne isolates and MTCC 1307 strain.

CONCLUSIONS

A close association was therefore found between phenotypic resistance against tetracycline and presence of tetracycline resistance genes. The tetA and tetB gene fragments were amplified, purified and sequenced. The gene sequences of the isolates studied herein were found similar to tetA and tetB gene sequences of other bacteria available in NCBI. The occurrence of tetA and tetB genes in B. cereus indicate the horizontal transfer of antibiotic resistance determinants from other bacteria into B. cereus. The transfer of these resistant determinants to other potentially pathogenic bacteria may be a matter of great concern.

Anti-infective Potential of Hot-spring Bacteria

Aim and Background:

Antibiotic resistance currently spans most of the known classes of natural and synthetic antibiotics; limiting our options for treatment of infections and demanding discovery of new classes of antibiotics. Much effort is being directed towards developing new antibiotics to overcome this problem. Success in getting novel chemical entities from microbial sources depends essentially on novelty of its habitat. The diversity of geographical location decides the type of micro-flora. In the past various terrestrial and aqueous microorganisms have provided several novel bioactive secondary metabolites of pharmaceutical importance. Hot-springs have not been as extensively exploited as other terrestrial resources. However, perseverance with such microbes augment the probability of getting novel bioactive compounds.

Materials and Methods:

Hot-springs soil samples were collected from Hot-springs in Maharashtra. Actinomycetes and other eubacteria were isolated from these soil samples by selective methods and purified. They were classified based on gram's nature and morphology. Six representative morphological strains were screened for their anti-infective potential by agar well diffusion method as reported by Nathan P. et al (1974). The bioactivity of the active microbes was confirmed.

Results:

Seventy three strains of bacteria encompassing eight actinomycetes, and 65 eubacteria were isolated and purified. Among the actives eubacteria PPVWK106001 showed broad spectrum antibacterial activity encompassing both gram positive and gram negative bacterial test models. The extract was active against resistant bacteria such as MRSA and VREs. Activity was very specific as there was no activity against fungi even at 100 fold concentration. The active principle was extractable in butanol.

Conclusions:

The study showed that Hot-springs exhibit diverse bacteria and it serves as potential reservoirs for bacteria of antimicrobial importance with diverse facet of activities. Thus Hot-springs microbes have ability to address issue of resistant bugs.

Silver triflate catalyzed synthesis of 3-aminoalkylated indoles and evaluation of their antibacterial activities

An efficient, one-pot synthesis was developed for 3-aminoalkylated indoles by three-component coupling reaction of aldehydes, N-methylanilines, and indoles using AgOTf as a catalyst. A series of twenty 3-aminoalkylated indoles was evaluated for their antibacterial activities against both Gram negative and Gram positive bacteria. Compounds 4b and 4r showed good antibacterial activity against both Gram positive and Gram negative strains. However, inversing the property of substituent (from 4r to 4q) resulted in the significant fall in the magnitude of antibacterial activity against Escherichia coli.

Bacterial outer membrane vesicles in disease and preventive medicine

Gram-negative bacteria have the ability to produce outer membrane-derived vesicles (OMVs) that are released into the extracellular milieu. Even though this intriguing phenomenon is well-known since many years, various aspects of bacterial OMVs are not fully described and are still in the process of being characterized in detail. One major reason for this is that depending on the bacterial species and its respective ecological niche, OMVs exhibit an enormous functional diversity. Research of the past years has clearly shown that OMVs of many pathogenic bacteria contribute to the virulence potential by enriching virulence factors and delivering them over long distances, superseding direct bacterial contact with their host. The subsequent interaction of OMVs with the host can occur at different levels regarding the type of immune response or the target cell type and may lead to different outcomes ranging from non-immunogenic activation or a pro-inflammatory response to cytotoxicity. In contrast to being virulence factors, OMVs are used for vaccination purposes in the combat against bacterial pathogens, and recent research thus is focused on to indirectly aim these versatile bacterial weapons against themselves.

Antibiotic use, resistance development and environmental factors: a qualitative study among healthcare professionals in Orissa, India

Background

Antibiotic resistance is a major public health problem affecting both current and future generations. The influence of environmental factors on antibiotic use and resistance development in bacteria is largely unknown. This study explored the perceptions of healthcare providers on antibiotic use and resistance development in relation to environmental factors i.e. physical, natural, social and behavioural factors.

Methods

A qualitative interview study was conducted using face-to-face, semi-structured interviews among registered allopathic doctors, veterinarians and drug dispensers in Orissa, India. The interview transcripts were analyzed using latent content analysis.

Results

The main findings of this study relate to two themes: 'Interrelationship between antibiotic use, resistance development and environment' and 'Antibiotic management contributing to the development and spread of resistance'. The interviewees viewed the following as possible contributors to antibiotic use/misuse and resistance development: changes in the natural and physical environment i.e. climate variability, pollution, physiography and population growth; the socioeconomic environment affecting health-seeking behaviour and noncompliance with medication; a lack of healthcare facilities and poor professional attitudes; and ineffective law enforcement regarding medicine dispensing and disposal.

Conclusions

Generally, the interviewees perceived that although behavioural and social environmental factors are major contributors to resistance development, changes in the physical and natural environment also influence development of antibiotic resistance. The respondents also perceived that there is a lack of information about, and poor awareness of, what constitutes prudent use of antibiotics. They suggested a need for information, education, dissemination and proper implementation and enforcement of legislation at all levels of the drug delivery and disposal system in order to improve antibiotic use and prevent pharmaceutical contamination of the environment.