Antibiogram Assay Research Articles

Biofilm Production Activity and Antibiotics Susceptibility of Streptococcus mutans Isolates from Patients with Dental Caries

Dental caries, a prevalent chronic infectious ailment, commences with the adherence of cariogenic bacteria to the teeth, particularly Streptococcus mutans. These microorganisms utilize sugars to produce acid, resulting in the gradual demineralization of the dental structure. Streptococcus mutans a gram positive bacterium is found to play the most significant role in the dental caries in terms of being the earliest colonizer in the formation of caries. The current research focuses on the isolation and identification of the Streptococcus mutans pathogen in individuals affected by dental caries. The isolated strains were cultured on specific media, with one hundred samples of dental caries obtained from human teeth. Among these samples, fifty were identified as positive bacterial isolates utilizing MS-agar (Mitist Salivares agar), with ten isolates categorized under the group Streptococci and twenty isolates identified as S. mutans. Identification of bacterial isolates was carried out based on morphological and cultural characteristics, biochemical tests, and VITEK-II. Additionally, an antibiogram assay was conducted to assess the susceptibility and resistance of the pathogen to various drugs. The findings revealed that all locally isolated S. mutans strains displayed 100% resistance to Cefepime, while showing different levels of resistance and susceptibility to other antibiotics such as Doxycycline, Amoxicillin-clavulanic acid, Trimethoprim-sulfamethoxazole, Vancomycin, Tetracycline, Ampicillin, and Meropenem. In this study, ELISA was employed to differentiate between Streptococcus. mutans isolates that produced biofilms and those that did not by utilizing the optical density at 630 nm. Bacterial biofilms contribute to chronic diseases that pose challenges in treatment. Twenty distinct isolates were evaluated for their biofilm-forming capabilities, with 9 (45%) identified as strong biofilm producers, 7 (35%) classified as moderate biofilm producers, and 4 (20%) categorized as weak biofilm producers

Ecological distribution of Staphylococcus in integrated farms within Washington DC–Maryland

AbstractMixed crop livestock farming (MCLF) is a growing practice in organic farming where livestock and crops are grown near each other to promote environmental sustainability through recycling. However, MCLF livestock are reservoirs of many zoonotic pathogens, such as Staphylococcus spp., and can serve as sources of cross‐contamination for plant food products. A surveillance study was conducted to determine the prevalence and antibiotic‐resistance patterns of various Staphylococcus spp. species isolated from the environment of multiple MCLFs and produced from pre‐harvest and post‐harvest levels within the DC–Maryland metropolitan area. A total of 3038 environmental and pre‐harvest produce and 836 post‐harvest produce samples were collected from eight farms and two retail supermarkets. In addition, 36 skin swabs from farmworkers and university students were also collected. PCR was used to confirm the presence of Staphylococcus spp. in all samples. Major species were identified using a species‐specific multiplex PCR. An antibiogram assay was performed to determine antibiotic resistance profiles. The overall prevalence of Staphylococcus spp. was 12.18% pre‐harvest and 7.54% post‐harvest. The most identified species was Staphylococcus epidermidis (19.86%), while most isolates remained unknown (73.90%). Approximately 83.33% of skin swabs were positive for Staphylococcus spp., with Staphylococcus xylosus being the predominant species (16.7%). The highest percentage of isolates were resistant to aminoglycosides and macrolides, with 24.11% of tested samples being multidrug‐resistant. S. epidermidis had the most resistance compared to the other species. This study suggests that antibiotic‐resistant Staphylococcus spp. is present in mixed farm environments, and proper steps need to be taken to control the transmission between livestock, crops, and humans.

Biogenic synthesis of silver nanoparticle by Cytobacillus firmus isolated from the river sediment with potential antimicrobial properties against Edwardsiella tarda.

The aquatic environment, independent of their host, is more favorable to pathogenic bacteria than the terrestrial environment. Consequently, pathogenic bacteria can reach very high densities around aquatic animals and can cause high mortality. The conventional approach, such as antibiotics, has minimal effectiveness. Additionally, due to the emergence of (multiple) resistance, their use is under intense scientific and public scrutiny. Hence, there is a need for the development of alternative control techniques, with an emphasis on prevention, which is likely to be more cost-effective. In this study, a potential bacterial strain Cytobacillus firmus was isolated from polluted river sediment and characterized using a comprehensive range of techniques including biochemical, 16S rRNA sequencing and antibiogram assay. The pathogenicity of the bacteria was tested in vivo on Labeo rohita fingerlings found as non-pathogenic. Further, the bacteria were found to synthesize silver nanoparticles (AgNPs) using AgNO3 as a substrate. The obtained AgNPs were characterized by various methods, including UV-vis spectroscopy, FTIR (Fourier-transform infrared spectroscopy), and Transmission Emission Microscopy (TEM). The study found that the AgNPs were 20 nm in size on average. The antimicrobial activity of synthesized AgNPs was examined against the model freshwater pathogenic bacteria, Edwardsiella tarda and both the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were 0.156 μM, while biofilm inhibition activity was also observed at 0.156 μM. The AgNPs showed no haemolytic activity at 0.313 μM. Our findings suggest that C. firmus mediated bacteriogenic AgNPs modulate the activity of common pathogenic bacteria E. tarda. The thoroughness of our research process gives us confidence in the potential of applying AgNPs in aquaculture as a considerable strategy to control the E. tarda infection.

Assessment of the prevalence, serotype, and antibiotic resistance pattern of Salmonella enterica in integrated farming systems in the Maryland-DC area.

Implementation of organic/pasture farming practices has been increasing in the USA regardless of official certification. These practices have created an increasingly growing demand for marketing safe products which are produced through these systems. Products from these farming systems have been reported to be at greater risk of transmitting foodborne pathogens because of current trends in their practices. Salmonella enterica (SE) is a ubiquitous foodborne pathogen that remains a public health issue given its prevalence in various food products, but also in the environment and as part of the microbial flora of many domestic animals. Monitoring antibiotic resistance and identifying potential sources contamination are increasingly important given the growing trend of organic/pasture markets. This study aimed to quantify prevalence of SE at the pre- and post-harvest levels of various integrated farms and sites in Maryland-Washington D.C. area, as well as identify the most prevalent serovars and antibiotic resistance patterns. Samples from various elements within the farm environment were collected and screened for SE through culture and molecular techniques, which served to identify and serotype SE, using species and serovar-specific primers, while antibiotic resistance was evaluated using an antibiogram assay. Results showed a prevalence of 7.80% of SE pre-harvest and 1.91% post-harvest. These results also showed the main sources of contamination to be soil (2.17%), grass (1.28%), feces (1.42%) and unprocessed produce (1.48%). The most commonly identified serovar was Typhimurium (11.32%) at the pre-harvest level, while the only identified serovar from post-harvest samples was Montevideo (4.35%). With respect to antibiotic resistance, out of the 13 clinically relevant antibiotics tested, gentamycin and kanamycin were the most effective, demonstrating 78.93 and 76.40% of isolates, respectively, to be susceptible. However, ampicillin, amoxicillin and cephradine had the lowest number of susceptible isolates with them being 10.95, 12.36, and 9.83%, respectively. These results help inform farms striving to implement organic practices on how to produce safer products by recognizing areas that pose greater risks as potential sources of contamination, in addition to identifying serotypes of interest, while also showcasing the current state of antibiotic efficacy and how this can influence antibiotic resistance trends in the future.

Electrospun Membrane Based on Poly(L-co-D,L lactic acid) and Natural Rubber Containing Copaiba Oil Designed as a Dressing with Antimicrobial Properties.

Drug delivery systems of natural antimicrobial compounds, such as copaiba oil (CO), have become relevant in the scientific community due to the recent prevalence of the public health complications related to antibiotic resistance. Electrospun devices act as an efficient drug delivery system for these bioactive compounds, reducing systemic side effects and increasing the effectiveness of the treatment. In this way, the present study aimed to evaluate the synergistic and antimicrobial effect of the direct incorporation of different concentrations of CO in a poly(L-co-D,L lactic acid) and natural rubber (NR) electrospun membrane. It was observed that CO showed bacteriostatic and antibacterial effects against S. aureus in antibiogram assays. The prevention of biofilm formation was confirmed via scanning electron microscopy. The test with crystal violet demonstrated strong bacteria inhibition in membranes with 75% CO. A decrease in hydrophilicity, observed in the swelling test, presented that the addition of CO promotes a safe environment for the recovery of injured tissue while acting as an antimicrobial agent. In this way, the study showed strong bacteriostatic effects of the CO incorporation in combination with electrospun membranes, a suitable feature desired in wound dressings in order to promote a physical barrier with prophylactic antimicrobial properties to avoid infections during tissue healing.

Investigating bio-remediation capabilities of a constructed wetland through spatial successional study of the sediment microbiome

Constructed wetlands (CWs) are engineered environments designed to utilise natural processes to treat urban or industrial wastewater, with the core driver of the bioremediation process provided by the microorganisms present within. This study isolated 32 bacterial strains from sediment across the Sardar Bherry CW to find candidates with remediation properties and to understand how the physiochemical gradient from wastewater input influences the functional properties of the bacteria present. Bacterial isolates recovered closer to the wastewater effluence were more likely to be pathogenic, with increased haemolytic activity, causing high rates of fish mortality. In contrast, isolates recovered further from the wastewater source were observed to be non-pathogenic and have increased inhibitory effect against pathogenic strains. Extracellular proteins extracted from non-pathogenic isolates also appeared to be effective at inhibiting the growth of pathogenic bacteria, including multidrug resistant strains. Non-pathogenic isolates recovered across all sampling sites displayed the ability to reduce high levels of ammonia in solution during laboratory testing. Antibiogram assays of the recovered isolates showed a relatively high rate of multidrug resistant or marginally resistant bacteria across all sampling sites, highlighting a potential limitation within the CW bioremediation process in mitigating antibiotic resistant strains. This isolate based study provided an avenue to understand the influence of spatial succession from wastewater effluence on bacterial characteristics, as well as obtain candidates that can be further investigated for optimisation in bioremediation efforts. The cultured isolates can supplement future environmental sequencing studies by providing wet lab specimens to compare (meta)genomic information discovered within the CW ecosystem.

DETECTION OF VANCOMYCIN INTERMEDIATE STAPHYLOCOCCUS AUREUS (VISA) OR VANCOMYCIN RESISTANT STAPHYLOCOCCUS AUREUS (VRSA) IN METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS (MRSA) STRAINS ISOLATED FROM A TERTIARY CARE HOSPITAL.

Introduction: Methicillin Resistant Staphylococcus aureus (MRSA) is a well-recognized public health problem throughout the world now days. The importance and prevalence of MRSA and its antibiotic pattern were occurred frequent modication for the last two decades. In routine antibiogram assay the susceptibility were screened by Disc diffusion method but drug usage and its knowledge may differs from each physicians, leads to VRSA in MRSA, can be prevented by determining drug susceptibility by Minimal Inhibitory concentration (MIC) technique MIC and knowledge about the drug usage. Detection of Vancomycin intermediate Staphylococcus aureus (VISA) or Aim: Vancomycin Resistant Staphylococcus aureus (VRSA) in MRSA by performing MIC and Disc diffusion method. A Materials and Methods: cross-sectional study was conducted on various samples for Anti-biogram screening in the Microbiology laboratory, tertiary care hospital. To perform Antibiotic susceptibility testing (AST), Disc diffusion method in Mueller Hinton agar was done in Staphylococcus aureus isolates. MIC of Cefoxitin and Vancomycin were performed for all isolates. All the MRSA isolates were checked for susceptibility to common antimicrobial agents such as Cefoxitin (30 μg), Penicillin (10 units), Clindamycin (2 μg), Erythromycin (15 μg), Linezolid (30 μg) and Cotrimoxazole (1.25/23.75 μg). SPSS version 23 used to analyses the data. Results: Total 200 S. aureus isolated over the period of 03 months, 78 were Methicillin Resistant (39 %). A 58% were from males and 42% were from females. Cefoxitin MIC50 was 16, Vancomycin MIC50 was 0.5 and Vancomycin MIC90 was 0.25 were obtained. Conclusion: Percentage of MRSA out of S. aureus isolates was 39 %. All the MRSA isolates had a Vancomycin MIC ≤1.5 μg/mL. The current study reveals that absence of VISA or VRSA in MRSA strains.

Microbial Resistance to Antibiotics and Biofilm Formation of Bacterial Isolates from Different Carp Species and Risk Assessment for Public Health.

The aim of this research was to investigate the effects of biofilm on antibiotic resistance of the bacterial isolates present in fish meat and to assess the risk of antibiotic residues for public health. Common carp, silver carp and grass carp fishes were purchased from retail stores for an in vitro biofilm investigation and a drug-resistant pattern determination. In all samples, up to 104 CFU/g of bacteria, such as Escherichia coli, Aeromonas hydrophila, Shewanella putrefaciens, Vibrio spp. and Staphylococcus spp., were observed. Isolates from the samples and their biofilms were subjected to an antibiogram assay using antibiotics such as amoxicillin, ampicillin, cefotaxime, ciprofloxacin, chloramphenicol, gentamicin, streptomycin, tetracycline and trimethoprim. Obtained results showed that some of the isolates were sensitive to antibiotics and some were resistant. Results of LC-MS/MS analysis showed that antibiotics residues were present in fish samples in the range between 4.9 and 199.4 µg/kg, with a total sum of 417.1 µg/kg. Estimated daily intake (EDI) was established to be 0.274 μg/kg of body weight/day for men and 0.332 μg/kg of body weight/day for women, with an acceptable daily intake (ADI) of 8.5 and 7.0 µg/kg of body weight/day for men and women, respectively. The results of the present study, therefore, highlight the safe consumption of fresh fish.

Facile synthesis of CuONPs using Citrus limon juice for enhancing antibacterial activity against methicillin-resistant Staphylococcus aureus, beta-lactamase and tetracycline-resistant Escherichia coli.

Antimicrobial resistance (AMR) resulting from indiscriminate use of antibiotics in various fields of agriculture such as livestock farming, aquaculture, and croup fields become an emerging catatroph for the health (human, animal) and environment. Among those, poultry farming has been considered as one of the major contributors of multidrug-resistant (MDR) bacteria. Focusing this, the present research is designed for green synthesis of copper oxide nanoparticles (CuONPs) with the aim of their application in antibiotic-free poultry farming for curving use of antibiotics in that sector. For that, antibacterial CuONPs were nanoformulated to decrease the required doses of bulk CuSO4. We used a CuSO4·5H2O solution as a Cu2+ source and Citrus limon juice as a reducing agent as well as capping agent. Particle yield was initially confirmed by the λmax specific to CuONPs (295 nm) using UV-Vis spectroscopy. The presence of the Cu-O group during particle formation and crystallinity with the purity of yielded NPs was confirmed with Fourier-transform infrared spectroscopy and X-ray diffractometry. The round to spherical CuONPs of 92-155 nm average size was confirmed with atomic force, scanning electron, and transmission electron microscopy. The concentration of yielded NPs was calculated with the dynamic light scattering. The physical characterization tools indicated a maximum CuONPs yield with a 0.001 M ion source with 15% reducing agents after 12 h reduction. Antibacterial effectivity was tested against methicillin-resistant Staphylococcus aureus and tetracycline- and beta-lactamase-resistant Escherichia coli, confirmed by PCR amplicon band at 163 bp, 643 bp, and 577 bp for the mecA, blaTEM-1 and tetA genes, respectively. An antibiogram assay of CuONPs showed a maximum zone of inhibition of 26 ± 0.5 mm for the synthesized particles. The minimum inhibitory and bactericidal concentrations were 1.6 μg ml-1 and 3.1 μg ml-1, respectively, for broad-spectrum application. Finally, the biocompatibility of CuONPs was determined by demonstrating a nonsignificant decrease of BHK-21 cell viability at <2 MIC doses for complying their future in vivo applicability.

Antibiotic Susceptibility Profile of Bacterial Pathogens and Health Hazards Associated with Municipal Solid Wastes in Gboko Town, Nigeria

Municipal solid wastes constitute one of the most challenging health and environmental hazards facing urbanizations in African countries. This study was therefore carried out on antibiotics susceptibility profile of bacterial pathogens and possible health hazards that could be associated with municipal solid wastes in Gboko town, Nigeria. Fourty samples were collected for bacteriological analyses. The municipal solid wastes collected were mixed homogenously, segregated and each segregate was weighed and recorded. The bacteriological loads and flora of the wastes were determined. The antibiogram assay of the isolates was carried out as well. A structured questionnaire was administered to households in order to assess the challenges and hazards associated with the wastes in Gboko town. The biodegradable bulks occupied the total mean of 63.59 % while the non-biodegradable matter formed the remaining 36.41% respectively. The bacterial isolates from the dumps with their respective percentage frequencies of occurrence and their mean percentage antibiotic susceptibility profiles in brackets were Salmonella typhi 84.12 (61.90), Escherichia coli 87.49 (50.00), Staphylococcus aureus 82.19 (60.44), Proteus sp 46.10 (91.11), Streptococcus sp (65.75 (83.33) and Pseudomonas aeruginosa 85.23 (60.32). The bacteria isolated are generally known pathogens; hence their presence in the dumps in such high prevalence levels could pose health hazards to the public in the town.

Sanitary status and water quality of some drinking water sources and antibiogram of Shiga toxin-producing Escherichia coli O157:H7 isolated from Shika, Zaria, Nigeria

ABSTRACT This study assessed the sanitary condition and quality of selected wells and boreholes in Shika, Zaria Nigeria. Fifty samples each were collected during the dry and wet seasons. This involved sanitary survey, water quality assessment, isolation and characterization of Shiga toxin-producing Escherichia coli O157:H7 (STEC) and, antibiogram assay. Based on the risk of contamination, wells (72%) had a high risk of contamination, while boreholes (44%) had low risk of contamination. Their physicochemical quality varied with season and location, and mean total coliform (TC) and faecal coliform (FC) were significantly lower in the dry season (p < 0.05). STEC were isolated from only wells with a prevalence of 4%, and exhibited a multidrug resistance pattern (amoxicillin, erythromycin and tetracycline). There was a strong positive correlation between sanitary status and water quality. The high- and very high-risk categories (wells) were strongly correlated with TC, FC, BOD, phosphate, turbidity and pH.

Bacterial Spectrum and Antibiotic Sensitivity in open Fractures of the Extremities

Background: Open fractures account for around 3 - 4% of all fractures, and infection caused by deprivation of bone and soft tissue, as well as loss of skeletal stabilization, is a serious consequence, particularly in grade III open fractures. Objective: To determine bacterial spectrum and antibiotic sensitivity in open fractures of the extremities Methodology: The current study was descriptive cross sectional study carried out at the department of Orthopedic Surgery, Khyber Teaching Hospital Peshawar for duration of six months from July 2021 to January 2022. All the samples were sent to the hospital diagnostic lab for bacterial identification and antibiogram assay. Kirby- Bauer method was used for antibiogram assay. The data was analyzed by using IBM SPSS version 19.0. Results: A total of 210 patients were included in our study. Male patients were 168(80%) and female were 42(20%). The major cause of fracture was traffic accident observed in 168 (80%) patients. Positive culture report was observed in 196 (93.33%) patients. Staphylococcus Aureus was most frequently observed in 115(54.76%) patients. High resistance against commonly used antibiotics was observed in our study. All the isolates were completely (100%) resistant to ampicillin. All the isolates were 100% sensitive to Amikacin except MRSA. Conclusion: Our study observed positive culture of bacteria in most of the open fractures of the extremities. Gram positive bacteria were most common than gram negative. Antimicrobial resistance was observed in majority of the bacterial isolates against commonly used antibiotics. Key words: Open fractures, Antibiotic sensitivity, Bacterial Culture, Extremities

Prevalence and Antibiotic Resistance Patters of Escherichia Coli Isolated From Milk and Milk Product

Milk contains many nutrients including carbohydrate, protein, fat, vitamins and minerals. Milk protein has high nutritional value because it contains all the essential amino acids. Considering the nutritive value, milk is widely consumed by the people as an ideal food. The biochemical changes in milk and milk products by microorganisms can be either desirable or undesirable. The safety of milk and milk products with respect to food borne diseases is of great concern around the world. Therefore, the present study was undertaken to determine the prevalence of Escherichia coli in milk and milk product with their antibiogram assay. A total of 150 milk and milk product (yogurt) samples were collected from Rajshahi Metropolitan area of Bangladesh and analyzed by cultural, staining and biochemical tests for the isolation and identification of E. coli. Antibiogram assay of all the isolates were done by disk diffusion method. The overall prevalence of E. coli was 20.0% in milk and milk product (yogurt) in Rajshahi Metropolitan area. The prevalence of E. coli was 26.0% and 34.0% in raw milk and in milk product (yogurt), respectively. E. coli was not detected in pasteurized milk in this study. In antibiogram assay, isolated E. coli showed 100.0%, 60.0%, 40.0%, 40.0%, 33.3%, 33.3%, 20.0%, and 10.0% resistance to penicillin, gentamycin, ampicillin, streptomycin, amoxycillin, sulfamethoxasole-trimethoprim, nalidixic acid, and ciprofloxacin, respectively. The isolates also showed 73.3%, 60.0%, 53.3%, 53.3%, 30.0%, 23.3%, and 20% sensitive to ciprofloxacin, nalidixic acid, sulfamethoxasole-trimethoprim, streptomycin, amoxycillin, ampicillin, and gentamycin, respectively. The findings of this experiment speculated that the use of ciprofloxacin and nalidixic acid may have the preference in the clinical control of milk borne E. coli infection in Bangladesh. J. Bio-Sci. 29(2): 81-91, 2021 (December)

Antibiotic susceptibility pattern of fish pathogens: A new approach of emerging the bacterial resistance through biofilm formation in in-vitro condition.

The ability of many bacteria to adhere on the host surfaces and forming biofilms has major implications in a wide variety of industries including the food industry, where biofilms may create a persistent source of contamination. In the same environmental condition, the multiple bacterial species can closely interact with each other and may easily enhance their drug resistance capability, which finally increases the multi-drug resistant (MDR) attribute of the species. The present study examined whether the mixed-species biofilm possesses any impact on the enhancement of the antibiotic resistance of the planktonic or single-cell bacterial isolates present in the fish samples. In this regard, Cyprinus rubrofuscus (Koi), Heteropneustes fossilis (Shing) and Mystus vittatus (Tengra) fishes were collected and subjected to form an in vitro biofilm by shaking condition into the wise bath. The drug-resistant pattern was determined by the Kirby Bauer technique. All the samples exhibited a huge array (up to 107 cfu/ml or g) of bacteria such as E. coli, Klebsiella spp., Vibrio spp., Salmonella spp., Proteus spp. and Staphylococcus spp. The isolates from both the bulk samples and their corresponding biofilms were subjected to antibiogram assay using antibiotics such as Ampicillin (10µg), Erythromycin (15μg), Streptomycin (STP 10μg), Oxacillin (10µg), Nalidixic acid (30µg). Before biofilm formation, few of the isolates were found to be sensitive and few were resistant against the antibiotics. But when the species were isolated from the biofilm the sensitive one acquired drug resistance and resistant strain unveiled more resistance towards the same antibiotics. The present study revealed extensive bacterial contamination in fish samples among those some were resistant against the supplied drugs. After the formation of multi-species biofilm, the isolates became more resistant against the same drugs that is alarming for consumers and major obstacles to maintain sustainable health.

Antimicrobial Evaluation of Extracts and Fractions of Daniella oliveri Leaf on Selected Clinical Enteropathogens

Background: Diarrhoea is one of the major health threats to the populace in the tropics, and also one of the killer diseases in children under 5 years of age. Antimicrobial resistance and its spread pose serious public health threats, hence the need for development of safer and more effective antibacterial agents. Daniella oliveri Hutch and Dalz is used in ethnomedicine for the treatment of diarrhoea and other gastrointestinal disturbances.&#x0D; Objective: To investigate the antimicrobial activity of Daniella oliveri leaves on diarrhoeal pathogens.&#x0D; Methods: Successive plant extraction was carried out with hexane, ethylacetate and methanol using soxhlet apparatus. Methanol extract was fractionated using vacuum liquid chromatography (VLC). Phytochemical screening was done using standard chemical assays. Antibiogram of test isolates was carried out using disc diffusion assay. Antimicrobial activity of plant extract and fractions against strains of diarrhoeagenic Escherichia coli, Salmonella cholerae-suis, Shigella dysenteriae, Proteus mirabilis and Acinetobacter baumannii was determined by agar well diffusion and MIC by agar dilution methods. Kill-kinetics study was carried out using viable count technique.&#x0D; Results: Terpenoids, steroids and anthraquinones were detected in fractions of D. oliveri. Antibiogram assay showed that 66% of isolates were MDR. Extract and fractions produced appreciable zones of inhibition on all challenge organisms except Acinetobacter baumannii. MICs ranged between 6.25-25 mg/ml. Kill kinetics studies showed total kill on susceptible pathogens after 24 hours.&#x0D; Conclusion: This research has shown D. oliveri is a promising drug candidate for the management and treatment of diarrhoea.

Identification and Antibiogram Assay of Escherichia Coli Isolated From Chicken Eggs

Chicken eggs contain all the essential components such as proteins, lipids, vitamins, minerals, carbohydrates, and growth factors required by the human being. Despite of their nutritional values eggs can cause health problems through consumption of contaminated eggs with pathogenic microorganisms. Therefore, the present study was undertaken to identify Escherichia coli isolated from chicken eggs with their antibiogram assay in Rajshahi district of Bangladesh. E. coli was isolated from 180 chicken eggs collected from different areas of Rajshahi district and identified based on cultural, staining, and biochemical characteristics. Antibiogram assay of all the isolates were done by disk diffusion method. The overall prevalence of E. coli was 38.89% in chicken eggs of which 27.78% was on egg shells and 11.11% was in egg content. The prevalence of E. coli was 58.33% in commercial layer farm eggs, 41.66% in whole seller eggs, and 16.67% in retailer eggs. In antibiogram study, isolated E. coli showed 64.28% to 92.85% sensitivity to chloramphenicol, gentamycin, and ceftriaxone. The highest sensitivity was found to meropenem (100%). Isolated E. coli showed resistance to ciprofloxacin, tetracycline, amoxicillin, ampicillin, and erythromycin ranging from 50% to 71.42%. Judicious use of antibiotics and public awareness will help to reduce the development of antibiotic resistance. J. Bio-Sci. 29(1): 123-133, 2021 (June)

Isolation and Characterization of Multidrug Resistant Enterobacteriaceae in Urine Sample of Patients Suffering from Urinary Tract Infection with Diabetes and Nephropathy

Multidrug-resistant (MDR) organisms are spreading widely and becoming an issue of utmost importance to deal with. In the current study, ten urine samples from diabetic patients suffering from multiple complications, including urinary tract infection (UTI) and nephropathy were investigated. Antibiogram assays of the bacterial isolates from collected samples demonstrated resistance against most of the antibiotics tested. Further studies were conducted to determine the types of resistant bacteria that caused UTI. Analyzing the 16S rDNA sequence and phylogenetic tree, 3 isolates were identified as Escherichia coli, 5 as Klebsiella pneumoniae and the rest 2 as Enterobacter asburiae. The findings of this research indicate the necessity of urgent attention to find an effective alternative drug for treating infections caused by these resistant isolates.&#x0D; Dhaka Univ. J. Pharm. Sci. 20(1): 87-93, 2021 (June)

Antimicrobial activity of bacteria isolated from tissue of the coral Palythoa caribaeorum (Zoantharia: Sphenopidae) from Paraíba, Brazil coastal reefs

Introduction: The coral-associated bacteria with antimicrobial activity may be important to promote the health of their host through various interactions, and may be explored as a source of new bioactive compounds. Objective: To analyze the antimicrobial activity of bacteria associated with the zoanthid Palythoa caribaeorum from the coral reefs of Carapibus, Paraiba state, Brazil. Methods: The phylogenetic analysis of the bacteria was conducted based on partial sequences of the 16S rRNA gene using molecular and bioinformatics tools. The antimicrobial activity of the 49 isolates was tested against four bacterial strains and one yeast strain: Bacillus cereus (CCT0198), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa and Candida albicans (ATCC 10231). The antibiosis and antibiogram assays were conducted and the Minimal Inhibitory Concentration (MIC) was determined by the microdilution method. Results: The bacterial isolates belonged to Firmicutes phylum (84 % of the isolates) and the Proteobacteria phylum (16 % of the isolates). Among the 49 isolates five genera were found, with the Bacillus genus being the most abundant (82 % of the isolates), followed by Vibrio (10 %), Pseudomonas (4 %), Staphylococcus (2 %) and Alteromonas (2 %). Antibiosis test revealed that 16 isolates (33 %) showed antimicrobial activity against one or more of five tested reference strains. The highest number of antagonistic bacteria were found in the Bacillus genus (12 isolates), followed by Vibrio (three isolates) and Pseudomonas (one isolate) genera. The B. subtilis NC8 was the only isolate that inhibited all tested strains in the antibiosis assay. However, antibiogram test with post-culture cell-free supernatant of NC8 isolate showed the inhibition of only B. cereus, S. aureus and C. albicans, and the lyophilized and dialyzed material of this isolate inhibited only B. cereus. The lyophilized material showed bacteriostatic activity against B. cereus, with a MIC value of 125 μg/μl, and in the cytotoxicity assay, the hemolysis value was of 4.8 %, indicating its low cytotoxicity. Conclusions: The results show the antimicrobial potential of some bacterial isolates associated with the P. caribaeourum tissue, especially those belonged to Bacillus genus.

An In Vitro Evaluation of the Biocidal Effect of Oregano and Cloves’ Volatile Compounds against Microorganisms Colonizing an Oil Painting—A Pioneer Study

In this study, the biocidal activity of two plant derivatives (oregano and cloves’ essential oils—EOs) was evaluated, as a potential innovative and eco-friendly cleaning method for canvas paintings. The object of the study was the oil painting on canvas entitled “Studio di nudo” (Giovanni Maria Mossa, 1921), showing stains caused by microorganisms. The research focused on: (1) isolation and identification of microorganisms associated with discolorations on the obverse and reverse sides of the canvas; (2) evaluation of biocidal activity of selected EOs against fungal and bacterial collections. The phylogenetic identification was conducted with both cultivation and molecular methods. The canvas was mainly colonized by Penicillium, Aspergillus, and Cephaloteca fungal genera and by bacteria of the Bacillus genus. To evaluate the biocidal effect of the EOs’ volatile components only, an antibiogram assay (agar disc diffusion method) and a customized assay (named the contactless test) were conducted. Tested EOs showed antimicrobial activity on fungi and bacteria. However, compared to cloves, oregano EO exhibited a better inhibition activity both in contact and contactless tests. The work is pioneering for the use of EOs’ volatile compounds against oil painting biodeteriogens, and gives insights into possible extended, innovative and eco-friendly cleaning methods for painting control procedures.

Evaluation of anarchic use of antibiotics in poultry farming

Background: Antibiotic are administered in presence and/or absence of disease and without prescription from physicians to increase production yield and mitigating animal health. With the aim of setting up an evaluation assay for the uncontrolled use of antibiotics in poultry farming. A survey was conducted in 13 farms. The study was aimed at assessing the abusive use of antibiotics in poultry farms in the Mfoundi Division. Methods and materials: A well-established questionnaire was conducted, June-July 2016, to determine the most utilized antibiotics and to collect litters .30 samples were collected from the farms under investigation and 250 g of each sample was collected and placed in sterile stomacher bags, and preserved under appropriate conditions prior to analysis. These litters permitted to have presumed isolates of Salmonella spp. through, the Salmonella-Shigella selective medium and then an antibiogram assay was carried out to determine the inhibition diameter in conformity with the recommendations of the Antibiogram Committee of the French Society of Microbiology (CASFM, 2015). A protocol based on the principle according to which, increase in turbidity presumed growth of Salmonella spp. in a broth containing an antibiotic at the Minimum Inhibitory Concentration (MIC) of the germ, is an indication of resistance, was performed by spectrophotometry at 600 nm within 10 h. Results: 100% of presumed isolates of salmonella were resistant to amoxicillin and erythromycin; 66.66% were resistant to tetracycline and oxytetracycline and 83.33% were resistant to ampicillin. The spectrophotometry method had a better result prediction percentage, of 66.07% (20/30) as compared to antibiogramm. Regarding the prediction errors, we observed that 23.33% (7/30) of the sensitive cases by antibiogramm were evaluated as being resistant by spectrophotometry whereas, 6.67% (2/30) of the revealed resistant cases by the classical method were evaluated as being sensitive by spectrophotometry. Oxytetracyclin was shown to be the antibiotic for which the results were least in conformity with those of the disc method. The elimination of oxytetracyclin in the spectrophotometry assay led to improvement of the predicted results. Conclusion: During the study, all farms used antibiotics and the resistance observed was attributed to the intensity of antibiotics utilized in the farms under investigation.