Most Probable Number Research Articles

IMPACT OF RHIZOSPHERIC, NODULATION AND SOIL MICROBIOME ON SOYBEAN AND RICE GROWTH FOR SUSTAINABLE AGRICULTURE

Microorganisms are critical for the survival of life on Earth, but we know very little about the vast majority ofmicrobes. We studied the culturable soybean root, soil, and nodules microbiome here. Thirty bacterial sampleswere isolated from different localities of soybean crops, including soil, root, and nodules, to assess their abilityfor plant growth promotion. To evaluate the richness and diversity in the root and soil, we performed the mostprobable number (MPN) test. Seven of the bacterial isolates were able to produce cellulase, in which JSW1 andJSW6 were most efficient with 2.56 and 2.05 cellulolytic index. All isolates were able to grow and utilizedpectin, in which JSW2 and JSW3 were most efficient with 0.8 and 0.66 pectinolytic index. Pikovskaya mediamodified with TCP JSW1 and JSW2 showed a 3.0 and 2.33 solubility index, and on CaCO 3 media, the JSW1strain produced a 1.58 solubilization index. All bacterial isolates were phylogenetically identified by sequencingand analyzing the 16S rRNA gene. Under controlled conditions, consortia, Pantoea dispersa, and Rhizobiumsp. isolates considerably improved rice root dry weight by 53%, 75%, and 69% and shoot dry weight by 85%,71%, and 76%. Based on in vitro characterization, the potential bacteria Pantoea dispersa, Pseudomonaskoreensis, and Rhizobium sp. were selected to be evaluated for plant growth, nodulation, and grain yield underfield experiment. Under field conditions, Rhizobium sp and Pseudomonas koreensis were found best as singleinoculation by improving 53% and 49% grain yield, respectively. These potential bacteria could be used asbiofertilizers for soybean crop productivity.

Phenol Biodegradation by Free and Immobilized Acinetobacter calcoaceticus K5 and Candida tropicalis YM2 Isolated from Persian Gulf

Phenols exhibit high solubility in water, leading to their potential to contaminate significant volumes of freshwater, wastewater, groundwater, oceans, and soil. The primary objective of this study is to isolate and identify bacterial and yeast isolates with optimal phenol degradation capabilities from Persian Gulf. Sea water and sediment samples were collected to isolate bacterial and yeast isolates, which were then evaluated for their ability to degrade phenol both in their single-cell form and when encapsulated in chitosan and alginate. The phenol-degrading strains were quantified using colony-forming unit (CFU) and most probable number (MPN) methods. The most promising microorganisms were selected and identified using phenotypic and polymerase chain reaction techniques. The selected isolates were immobilized in alginate and chitosan carriers, and their bioremediation potential was assessed at different phenol concentrations. The removal of phenol by the isolates was confirmed using Gas Chromatography. Through molecular techniques, Acinetobacter calcoaceticus K5 and Candida tropicalis YM2 were identified as the most efficient phenol-degrading strains. Acinetobacter calcoaceticus K5 exhibited the highest growth at phenol concentrations of 200 and 300 ppm, while Candida tropicalis YM2 showed optimal growth at a concentration of 700 pp. In case of Acinetobacter calcoaceticus, chitosan immobilization and a phenol concentration of 500 ppm proved to be the best conditions for phenol bioremediation. In the case of Candida tropicalis YM2, the highest percentage of phenol removal was achieved using the chitosan carrier at a concentration of 1000 ppm. Comparing the immobilized strains to their free counterparts, it was observed that the stabilized bacteria exhibited greater phenol removal efficiency, particularly at a concentration of 500 ppm, with a significant difference between the two conditions. This study demonstrates that the novel strains Acinetobacter calcoaceticus K5 and Candida tropicalis YM2 are efficient strains for the bioremediation of various phenol-contaminated seawater and this is the first report to show such rapid phenol degradation by these organisms isolated from sediment and seawater samples collected from Persian Gulf.

Enterococcus Species and Their Antimicrobial Resistance in an Urban Watershed Affected by Different Anthropogenic Sources

Different anthropogenic sources can have a significant influence on bacterial populations and their antimicrobial activities. In this study, the impact of anthropogenic activities on Enterococcus species was studied in an urban watershed in southern California affected by concentrated animal feeding operations (CAFOs), recreational activities, wastewater treatment plants (WWTPs), urban runoff, and control sites. Water samples were collected quarterly for two years for the enumeration of Enterococcus species based on the Enterolert most probable-number (MPN) assay. Concentrations of enterococci were higher in the sediment compared to surface water (4.5 × 106 CFU/g of sediment vs. 2.3 × 105 MPN/100 mL of water). The species diversity was dominated by E. mundtii (32%), E. faecalis (27%), and E. faecium (25%). E. faecium exhibited the highest antibiotic-resistant phenotype. Resistances were mostly to ciprofloxacin, erythromycin, and tetracycline. Tetracycline and erythromycin resistance genes, encoded by tet (C, K, O, S) and ermB, respectively, were more common in isolates from sediment (42.9%) compared to water (12.7%). E. mundtii was sensitive to ampicillin, chloramphenicol, gentamicin, and high levels of vancomycin. A significant percentage of E. faecalis were also resistant to these antibiotics. E. faecium and E. faecalis exhibited resistance to multiple antibiotics. Our data suggest that resistant Enterococcus species within the watershed might provide some useful data to determine pollutant types and sources in that watershed. Therefore, the widespread occurrence and abundance of E. faecium and E. faecalis, and their resistance genes associated with multiple antibiotics may potentially pose risks to the local populations exposed to these water sources during recreational activities.

Prevalence and Diversity of Antibiotic Resistance Heterotrophic Bacteria Found Along the Bintulu Rivers, Sarawak

The study aims (1) to isolate and characterise the heterotrophic bacteria from different rivers in Bintulu, Sarawak, (2) to investigate the hygienic condition of the rivers through faecal coliforms and (3) to determine the antibiotic resistance among the heterotrophic bacteria isolates. A total of 100 heterotrophic bacteria strains were identified from rivers of Bintulu, Sarawak. The characterisation of bacteria was performed using (GTG)5 fingerprinting to investigate their genetic distribution diversity and 16S rRNA gene sequencing. Microbiological variables tested including total viable count, coliform count, Escherichia coli confirmation test. Antibiotic susceptibility test was performed against 10 antibiotics. Sample collected from Sungai Teknik showed higher mean bacterial population size (log 4.48 ± 0.00 CFU/mL). Sungai Sibiu, Waterfront and Sungai Plan revealed the highest most probable number (MPN) index (>1,600 per mL). Each dendrogram showed 3 to 7 clusters of bacteria groups confirmed as Enterobacter spp. (40%), Acinetobacter spp. (13%), Bacillus spp. (13%), Klebsiella spp. (13%), Staphylococcus spp. (7%), Chromobacterium spp. (7%) and Citrobacter spp. (7%). All the heterotrophic bacteria isolated showed high resistance against ciprofloxacin (63.70 ± 33.40%), piperacillin (58.10 ± 31.37%), aztreonam (48.40 ± 30.95%) and more susceptible to tetracycline (3.30 ± 10.44%). Our findings highlight the multiple antibiotics resistance and microbiological analysis of heterotrophic bacteria found in polluted river water. The preservation of the river water is vital as hydrologic purposes, sustain the microbial composition, ecological integrity of the river.

Reduction of Nontyphoidal Salmonella enterica in Broth and on Raw Chicken Breast by a Broad-spectrum Bacteriophage Cocktail

Globally, nontyphoidal Salmonella (NTS) causes approximately 150 million foodborne illnesses annually; many of which are linked to poultry products. Thus, improving food safety interventions in the poultry sector can reduce foodborne illness associated with prevalent NTS serotypes. Bacteriophages (phages) have shown promise as food-safe alternatives to current antimicrobial practices. However, challenges such as limited host range, bactericidal effectiveness in practical production settings, and the risk of developing host resistance remain as barriers for the widespread use of phages in commercial poultry operations. A broad-spectrum three-phage cocktail was evaluated against S. enterica subsp. enterica serotypes Enteritidis, Typhimurium, and Kentucky. The impact of multiplicity of infection (MOI) on NTS growth was assessed in broth at 22°C for 18 hours (h). Then, phage cocktail efficacy was evaluated on raw chicken breast samples inoculated with the NTS cocktail and stored at 10°C or 22°C for 0, 1, and 5 days or 0, 4, 8, and 16 h, respectively. Most probable number (MPN) calculations were performed for NTS counts on chicken after phage treatment and storage at 10°C to account for samples with NTS counts below the detection limit. In general, a higher MOI corresponded to reduced NTS growth; however, residual nutrition in growth media and initial NTS contamination level affected samples treated with the phage cocktail at identical MOIs. On chicken, phage cocktail treatment significantly reduced NTS counts at 10°C and 22°C. After storage at 10°C for 5 days, NTS counts were reduced by >3.2 log compared to the control. After storage at 22°C for 16 h, NTS counts were reduced by >1.7 log compared to the control. Overall, the phage cocktail was effective at reducing a diverse set of prominent NTS strains in broth and on raw chicken breast, highlighting its potential for commercialization and use alongside other hurdles in poultry production.

Impedance method application for number detection Escherichia coli in molluscs testing by official laboratory

Bivalve molluscan shellfish (BMS) have an important role in the transmission of some pathogens responsible for food-borne disease because they are filter-feeding animals capable of greatly concentrating certain pathogenic agents (bacteria, viruses, or parasites) present in the water column, like Escherichia coli. The reference method for E. coli testing in bivalves is the most probable number (MPN) method therefore, as this method has some disadvantages, alternative techniques of equivalent accuracy could be used without the drawbacks of the MPN method such as the direct impedance technique. This method is based on the principle that bacteria produce positively or negatively charged end products causing an impedance variation of the medium that can be used to measure their growth. The present study evaluated the efficiency of the direct impedance measuring technique through a series of laboratory tests performed on 6 kg of clams belonging to two different batches. The preliminary obtained data, compared with the MPN reference method and dd-PCR to validate the alternative method, show that the direct impedance technique has the potential to be used in place of TBX culture for confirming E. coli in MPN assays.

Medium-term storage of calf beddings affects bacterial community and effectiveness to inactivate zoonotic bacteria

Land-spreading of animal faecal wastes -such as animal beddings- can introduce zoonotic enteropathogens into the food system environment. The study evaluated the effectiveness of animal beddings naturally contaminated by calf manure to reduce E. coli O157:H7 or Salmonella enterica. The two pathogens were introduced separately as a four strains-cocktail and at high (>6.5 Log10 g-1) concentration into bedding materials, and their inactivation over a 10 weeks-period was monitored by using a Most Probable Number (MPN) enumeration method. Inactivation of E. coli O157:H7 was more effective in the bedding inoculated immediately after collection from calf pens than in the beddings inoculated after a 2 months-pre-storage period: E. coli O157:H7 levels were reduced by 6.6 Log10 g-1 in unstored bedding (0.5 Log10 g-1 recovered; 95%CI: 0.0–1.2), and by 4.9 Log10 g-1 in pre-stored bedding (2.2 Log10 g-1 recovered; 95%CI: 1.5–2.8) with a significant (p<0.05) difference between unstored and pre-stored. S. enterica was inactivated less effectively as counts were reduced by one order of magnitude, with no significant difference in inactivation between unstored and pre-stored beddings. Low levels of naturally occurring E. coli O157 and Salmonella spp. were detected in the non-inoculated beddings, as well as in the straw prior to use in the animal facility. To better understand the possible biological processes involved, the bacterial community present in the beddings was characterised by short-read 16S rRNA sequencing. Pre-storage of the bedding affected the composition but not the diversity of the bacterial community. Analyses of the key bacterial phyla suggested that the presence of a diverse and stable bacterial community might facilitate inactivation of the introduced pathogens, and a possible role of bacterial orders associated with lignocellulolytic resources. Overall, the study contributed to the understanding of the fate of zoonotic bacteria introduced in animal beddings during storage and identified bedding storage practices pre-and post-use in animal facilities that could be important to prevent the risk of zoonosis dissemination to the environment or to the dairy herds.

Genomic insights into Enterococcus faecium isolates from marine bivalves highlight One Health concerns and healthcare linkages.

Enterococci, especially Enterococcus faecium, are one of today's leading causes of multidrug-resistant infections in hospital settings. The marine environment may harbour enterococci, but its role as an evolutionary niche and as a vector for the spread of enterococci is sparsely investigated. Hence, by applying enterococci in bivalves as a sentinel tool, this study aimed to describe the prevalence of enterocooci along the Norwegian coast and in addition the phylogeny of E. faecium in particular. Enterococci in batch samples of marine bivalves, harvested from 86 different locations, were quantitatively examined by a culture-dependent most probable number (MPN) method. Isolates were identified by MALDI-TOF-MS prior to antimicrobial susceptibility testing by broth microdilution. In-detail analyses of a representative selection of E. faecium isolates (n=148) were done by Illumina whole-genome sequencing, and assembled genomes were compared to closed E. faecium genomes in the public databases and to genomes from commensal and clinical isolates from Norway. Diversity among E. faecium within the same batch sample of bivalves was also explored. Enterococci were detected in 287 of the 471 examined bivalve samples, but in low concentrations with a median value of <18 MPN /100 g. From positive samples, 479 isolates of enterococci were identified belonging to ten different species, where E. faecium (n=247), Enterococcus hirae (n=114) and Enterococcus faecalis (n=66) were most frequently found. Resistance towards one or more antimicrobial agents was observed in 197 isolates (41 %), none of the isolates showed acquired resistance to vancomycin or linezolid. Phylogenetic analyses revealed high diversity among the E. faecium isolates and showed that the marine niche is dominated by strains from the non-clinical setting belonging to clade A2 (n=85) and B (E. lactis) (n=60). Only three isolates belonged to the hospital-associated clade A1 (ST80 and ST117). Two of these clustered with one isolate from a hospitalized patient and one from a non-hospitalized person. This study demonstrated a high prevalence, but low concentrations of enterococci in bivalves, and low levels of antimicrobial resistance. E. faecium genomes showed high population diversity and that very few E. faecium isolates in bivalves may have arisen from the human healthcare system. A systematic surveillance of target micro-organisms applying methods examining multiple isolates from the same bivalve sample provides important data to assess the enterococcal phylogeny, antimicrobial resistance and the level of faecal pollution in the marine environment.

Isolation and Identification of Phenol-Degrading Bacteria from Iranian Soil and Leaf Samples.

By considering the importance and role of soil in the health of humanity, it is important to remove the presence of harmful compounds, such as phenol. In this study, four types of soil and leaf samples were collected from Kerman, Iran, and the amounts of heterotrophic and degradation bacteria were determined using the serial dilution and most probable number (MPN) methods. The amount of removed phenol was investigated using the Gibbs method with different concentrations of phenol. Then, an isolate with the highest percentage of phenol degradation was identified as the superior strain using 16 sRNA sequencing. The effects of the different factors, such as the carbon source (1% molasses and 1 g glucose), nitrogen source (0.1 g yeast extract), mixed culture, and time (14 and 28 days), on the biodegradation ability of the superior strain was investigated. A total of 18 bacterial strains were isolated from the samples. Isolate B3 had the highest rate (75%) of phenol degradation, at a concentration of 1000 ppm, meaning it was identified as the superior strain. The molecular analysis results identified this isolate as the Comamonas testosteroni strain F4. This bacterium can degrade 89% of the phenol at 30 °C, 180 rpm, and 800 ppm over 28 days. C. testosteroni did not show a favorable phenol degradation ability in the presence of the investigated carbon sources, while this ability was also reduced in mixed cultures. C. testosteroni bacterial strain isolated from soil samples of pistachio orchards in Kerman, Iran, has a favorable ability to biodegrade phenol.

Bacteriological Quality Test of Southeast Sulawesi Honey to Support Functional Food

Honey is widely utilized as a food and beverage additive in the industrial field, as a cosmetic ingredient, and as a medicinal ingredient from ulcer disease, coronary heart disease. However, honey does not always have guaranteed quality, because the processing process is less hygienic, so that microorganisms can grow and multiply, and become less safe if consumed. The purpose of the study was to test the bacteriological quality of processed honey in the people of southeast Sulawesi. This type of research is an experiment using the MPN (Most Probably Number) method, identification test, gram staining, biochemical tests. The results showed that out of 20 honey samples, 6 honey samples were found to be positive for Coliform bacteria, of the 6 positive samples, biochemical testing was continued and 1 sample was found to be positive for E.coli bacteria. The conclusion of the study is that the Colifrom and E. coli bacteria found in honey samples in dunga come from the containers used that are less hygienic.

Room sterilization using ultra violet lamps in reducing the air germs number of tuberculosis patients’ house

Mycobacterium Tuberculosis can survive in the air, with its ability depending on environmental factors such as Ultraviolet (UV) light. UV light can be generated from sunlight or UV-C lamps, which are utilized for air germ sterilization. This study aimed to assess the efficacy of room sterilization using a UV lamp in reducing airborne germ counts. This experimental research took place from March to September 2023 and employed a one-group pretest-posttest design. The research was carried out in 21 houses of tuberculosis patients in Kupang City. The intervention involved the use of 16-watt and 20-watt UV lamps in two rooms of each house. The variable measured was the airborne germ count, assessed by examining the Most Probable Number (MPN) coliforms, both before and after sterilization (UV light irradiation), calculated through laboratory examination. The collected germ count data were then statistically analyzed using the paired t-test. Room sterilization using a 16W UV lamp effectively reduced the number of room germs (p-value 0.046 &lt; 0.05). Similarly, room sterilization with a 20W lamp significantly reduced the number of room germs in the households of tuberculosis patients (p 0.004 &lt; 0.005). Ultraviolet lamps can be employed for sterilizing rooms in the homes of tuberculosis patients, particularly in cases where sunlight cannot penetrate the house. These lamps can eliminate airborne germs, thereby reducing their count and the risk of disease transmission within the household.

Pathogenic bacteria contaminant and heavy metal content in peeled green mussels sold in the traditional market in Yogyakarta Indonesia: a case study in 2022

Food is needed to prevent foodborne illness. This study aimed to detect pathogenic bacteria contaminants and heavy metal content in peeled green mussels sold in the traditional market of Yogyakarta, Indonesia. This research is a descriptive study with random sampling. A total of 33 samples examined E. coli., and Salmonella sp., contamination based on the most probable number (MPN) method whereas heavy metal content by atomic absorption spectrophotometry (AAS). Contamination of E. coli., and Salmonella sp., were 33.3% and 9.09% respectively, exceeded by SNI 7388:2009 limits of microbial in food contamination (MPN Salmonella sp., negative/25g and MPN E. coli., <3/g). The levels of Pb and Hg in the food sample were found to be above the limit set by the Food and Drug Supervisory Agency of the Republic of Indonesia in 2018, which is greater than 0.5mg/kg. However, the levels of As and Cd were still within the limit allowed by the regulatory agency, which is less than 0.1mg/kg. It’s important to ensure that food products meet the established safety standards to protect consumers’ health and well-being. Peeled green mussels sold in traditional market in Yogyakarta, Indonesia contaminated with pathogenic bacteria and contains Pb and Hg metal.

ANALISIS CEMARAN MIKROBIOLOGI BEBERAPA ASPEK PRODUKSI PADA PEDAGANG PENYEDIA MAKANAN DI SEKITAR KAMPUS UNIVERSITAS BUMIGORA MATARAM

Most health problems by food are caused by contamination of microorganisms. This contamination can due because cleanliness or improper implementation of sanitation and hygiene. The aim of this research is to identify microorganism contamination in the production aspects of food traders around the Campus of Bumigora University Mataram. Total microbial testing was carried out using the Total Plate Count (TPC) method for air, table, floor, equipment and water samples. Another method for testing coliforms in water use the principle of the Most Probably Number (MPN) method. The observation results show that the environmental quality as seen from the total microbes in the air is below the threshold, namely &lt;700 col/m3, so it is said to be still safe. Meanwhile, table, floor and equipment samples showed that the total number of microbes was high enough to exceed the required threshold, especially those related to eating utensils such as plates, glasses and spoons. The total microbial test in the water sources used by the three traders showed that the two water sources used contained microbial colonies which were tested via TPC with colony numbers ranging from 87.7 – 99 x 10-5 CFU/ml. The results of the coliform estimation test using the MPN method principle showed that there was no suspicion of any coliform bacteria contamination in the two water samples, which indicated that both water sources also met the clean water requirements according to Minister of Health Regulation No. 492 of 2010.

Analysis of Escherichia coli and Total Plate Count of Red Guava Fruit Juice (Psidium guajava L.) Sold in Keboansikep Gedangan Subdistrict Sidoarjo

Red guava can be processed into a juice drink, but it does not rule out the possibility that fruit juice contains disease-causing microorganisms. This study aims to determine the number of Escherichia coli and TPC/Total Plate Count bacteria in red guava fruit juice sold in the Keboansikep, Gedangan, Sidoarjo. The method used is descriptive using a survey technique with a cross-sectional approach. Laboratory experiments are carried out, namely analyzed in the microbiology laboratory sampling using a saturated sampling technique. Samples were examined to compare the analysis results obtained compared to INS 3719:2014 concerning the Quality of Fruit Juice Drinks. Samples were examined using Escherichia coli analysis based on INS 01-2332.1-2006 with the Most Probable Number (MPN) method and Total Plate Count/TPC analysis based on INS 01- 2332.3-2006 with the pour plate method. The test results showed that the Escherichia coli analysis obtained 100% of the samples showing positive with the lowest MPN index of 9 APM/ml to the highest &gt;1100 APM/ml. The results of the PNA analysis obtained 7% of all samples, indicating that it was safe and met the requirements, namely sample 7A with a TPC value of 4.9 x 103 CFU/ml, while 93% of all samples showed that it was unsafe or did not meet the requirements based on INS 3719: 2014. The sample containing the most microbes was sample 5A with a TPC value of 5,1 x 105 CFU/ml

Microbial Quality of Some Fresh-Cut Ready-to-Eat Fruits Sold in Some Markets and Bus Terminals in the Kumasi Metropolis, Ghana

The consumption of fruits is an important source of vitamins and micronutrients. Despite their health benefits, fruits have been linked to food-borne infections, particularly when untreated animal excreta are used in their cultivation and not properly washed before consumption. This study aimed to evaluate the parasitological, fungal, and bacteriological quality of some fresh-cut ready-to-eat fruits sold in markets and bus terminals in the Kumasi Metropolis, Ghana. A total of 270 fresh-cut ready-to-eat fruits, including pineapples, watermelon, pawpaw, sugarcane, and tiger nuts, were sampled from both stationary vendors and hawkers from six different locations in the Kumasi Metropolis. Samples were analysed for the presence of bacteria, fungi, and intestinal parasites using the Microbial Methods in the Bacteriological Analytical Manual (BAM) of the United States Food and Drugs Administration (2001). The pour plate technique was used to culture and grow bacteria and fungi, while the most probable number (MPN) table was employed for bacteria and fungi count. The total coliform counts ranged from 2.32 to 3.15 log cfu/g; faecal coliform counts ranged from 1.58 to 2.58 log cfu/g; enterococci count ranged from 1.06 to 1.90 log cfu/g; and fungal count ranged from 2.57 to 3.73 log cfu/g. There was a significant difference in the mean faecal coliform and enterococci counts for all fruit samples. Tiger nut had the most bacteria, while watermelon was the most fungi contaminated fruit. Shigella spp. was the commonest bacteria contaminates of fresh-cut ready-to-eat fruits sold in Kumasi. Giardia lamblia was the most abundant parasite detected. Fresh-cut ready-to-eat fruits and vegetables sold in markets and bus terminals in the Kumasi Metropolis, Ghana, are contaminated with bacteria, parasites, and fungi. These findings emphasize the need for public awareness and proper hygiene practices to reduce the risk of food-borne illnesses associated with the consumption of fresh-cut fruits.

Distinct Effects of Moxifloxacin and Bedaquiline on Growing and 'Non-Culturable' Mycobacterium abscessus.

Mycobacterium abscessus has recently emerged as the cause of an increasing number of human infections worldwide. Unfortunately, it is highly resistant to existing drugs, and new specific agents to combat M. abscessus have not yet been found. The discovery of antibiotics that are effective not only against replicating but also against dormant and often recalcitrant cells is a daunting challenge. In this study, we developed a model of non-replicating M. abscessus, which represents a valuable screening tool for antibacterial agents. Thus, we demonstrated that, under a deficiency of potassium ions in the growth media and prolonged incubation, M. abscessus entered a 'non-culturable' state with a significant loss of colony-forming ability, but it retained viability, as confirmed using the most-probable-number (MPN) assay. The 'non-culturable' mycobacteria possessed decelerated cellular metabolism and noticeable differences in cell morphology from actively growing mycobacteria. 'Non-culturable' cells were used in a comprehensive screening of the efficacy of antibiotics, along with actively growing cells. Both CFU and MPN tests confirmed the prominent bactericidal effect of moxifloxacin on actively growing and 'non-culturable' M. abscessus, as proven by less than 0.01% of cells surviving after antibiotic treatment and prolonged storage. Bedaquiline exhibited a comparable bactericidal effect only on metabolically inactive non-culturable cells aged for 44 days. There were reductions ranging from 1000 to 10,000-fold in CFU and MPN, but it was not so efficient with respect to active cells, resulting in a bacteriostatic effect. The demonstrated specificity of bedaquiline in relation to inert non-replicating M. abscessus offers a new and unexpected result. Based on the findings of this research, moxifloxacin and bedaquiline can be regarded as potential treatments for infections caused by M. abscessus. In addition, a key outcome is the proposal to include the combination of viability assays for comprehensive testing of drug candidates. Relying on CFU-based assays alone resulted in overestimates of antibacterial efficacy, as demonstrated in our experiments.

Analysis of coliform bacteria contamination in drinking water refill in Ambon City

In recent years, refillable drinking water businesses have grown rapidly in several cities in Indonesia, including Ambon City. On the one hand, Refillable Drinking Water Depots (DAMIU) support efforts to realize a healthy society by expanding the reach of clean water consumption, On the other hand, DAMIU tend to be problematic when faced with business interests. Feces contain coliform bacteria which is an indicator of water contamination. This study aims to determine the presence of coliform bacteria in Ambon City. The samples used in the study came from three sub-districts of refill drinking water depot sources, namely the Teluk Dalam sub-district, Nusaniwe sub-district, and Baguala sub-district. Microbiological testing of refill drinking water using MPN (most probable number) method. The MPN test results showed that three refill drinking water samples were not contaminated with coliform bacteria because there was no turbidity or gas formation in the Durham tube for gas-forming bacteria. This indicates that the three refill drinking water samples tested microbiologically have good quality and are safe for consumption, because in 100 ml of water no coliform bacteria were found in accordance with Permenkes No. 492/Menkes/Per/IX/2010 regulations on the requirements and supervision of water quality, which states that the microbiological requirements for drinking water are MPN Coliform /100 ml sample = 0. There are no coliform bacteria in the refillable drinking water depot in Ambon City so the water is suitable for consumption

Multiple drug resistant enterobacteria from biofilms in some tap water supplies in a Nigerian university

Tap outlets have been found to contain biofilms, which are a consortium of bacteria, fungi, viruses and protozoa. These microorganisms, especially Gram negative bacteria, could be pathogenic and highly resistant to antibiotics, leading to an increase in the prevalence of diseases worldwide. The university community depends on water from boreholes for consumption and domestic uses; as such, the need to identify the Gram negative bacteria is expedient. The main objective of this research is to determine the potability of the water released from the taps, and ultimately reduce the incidence of biofilm-related water infections. Water samples were collected from five boreholes and five tap outlets were swabbed with a sterile swab stick. Coliforms were estimated from the water samples using the Most Probable Number (MPN) technique. Gram negative bacteria were isolated and identified from the swabbing using standard bacteriological and biochemical tests. The antibiotic resistance patterns of the isolates were also determined, and the genes responsible for the multiple antibiotic resistance were identified using the DNA extraction and Polymerase Chain Reaction (PCR) methods. Bacterial counts of the samples ranged from 6.0×105cfu/mL to 1.4×106cfu/mL. MPN values of the tap water samples ranged from 4 to 1100+cfu/100mL, which exceeded the WHO standards of water quality. A total of 31 bacteria were isolated, of which 8 (25.8%) were Pseudomonas sp, 7 (22.6%) were Proteus sp, 4 (12.9%) were Klebsiella sp, 4 (12.9%) were Escherichia coli, 3 (9.7%) were Enterobacter sp, 3 (9.7%) were Citrobacter sp and 2 (6.5%) were Salmonella sp. All the bacteria showed multiple drug resistance to different antibiotics used, especially the cephalosporins. The gene found to be responsible for the cephalosporin resistance was the TEM - 445. Tap swabbing and water samples were found to contain a high value of coliforms (4 – 1100cfu/100mL), showing heavy faecal pollution, many of which could be pathogenic microorganisms that renders the water unfit for human consumption. The presence of these multidrug resistant microorganisms in the tap outlets could pose a serious threat to public health.

The Influence of Sanitation and Hygiene Systems on The Existence of Escherichia Coli Bacteria in Products of Pindang Fish at Kusamba Centers, Klungkung, Bali

Hygiene and sanitation are essential factors in fish processing to ensure food availability and safety. Escherichia coli causes foodborne illness, originating from pindang fish from the Kusamba breeding center, Klungkung Regency, Bali. Availability and security of food cover cleanliness are essential to hygiene and sanitation, where Escherichia coli indicates food contamination. This study aims to determine the bacteriological quality of boiled pindang products and the effect of sanitation and hygiene on the presence of E. coli in pindang products conducted at the Fish Preservation Center in Kusamba Village, Klungkung, Bali in November-December 2022. The study used a quantitative method with a cross-sectional approach and analysis. The laboratory uses the MPN (Most Probable Number). I was preparing a handling strategy with a SWOT analysis. The results showed that environmental sanitation and personal hygiene had a significant effect. MPN test results obtained a positive percentage of 93.1% and a negative of 6.9%. Of the 44 hospital wards, the results could have been better in environmental sanitation at 11.3 %, equipment sanitation at 6.8%, and personal hygiene at 8.1%. The implementation strategy to minimize the presence of E.coli bacteria is maintaining the unity of the quality system by carrying out sanitation and hygiene, starting from raw materials, processes, and products.

A calibration-free, non-invasive, and accurate total viable count detection method based on tunable diode laser absorption spectroscopy combined with most probable number counting

Total viable count (TVC), as an important indicator in the microbiological detection. A calibration-free, non-invasive, and accurate TVC detection method was developed using the most probable number (MPN) method and tunable diode laser absorption spectroscopy (TDLAS). In the experiment, a tunable distributed feedback (DFB) laser with a center wavelength of 4989.97 cm−1 was used to measure CO2 emitted from the microorganisms in a sealed culture bottle. Then, the thresholds of negative and positive culture bottles in the MPN-TDLAS method were established by the features of the Staphylococcus aureus (S. aureus) growth curve. The experimental results revealed that the MPN-TDLAS method has a good correlation (R2 = 0.99) with the TVC of the ISO:4833:2013 standard plate counting method, and the result of the quality control (QC) sample was satisfactory (Z-score was less than 2), which demonstrated that this method is well-suited for food microbiology testing applications.