Carriers Of Microorganisms Research Articles

Microbial inoculants using spent mushroom substrates as carriers improve soil multifunctionality and plant growth by changing soil microbial community structure

Peat is typically used as a carrier for microbial inoculants; however, due to its non-renewable nature alternatives need to be identified as reliable and renewable carriers for mineral-solubilizing inoculants. In pot experiments, solid microbial inoculants were comprised of peat (P), biochar (BC), and spent mushroom substrates (SMS) using Medicago sativa L. as experimental materials, and the purpose of this study is to assess the effect of solid microbial inoculants on soil multifunctionality and plant growth. The results revealed that the SMS microbial inoculant had the greatest positive impact on plant biomass and significantly stimulated soil multifunctionality which is typically managed or assessed based on various soil functions or processes that are crucial for sustaining productivity, in contrast to the peat microbial inoculant, particularly at a supply level of 100 g/pot. There was no significant correlation between soil multifunctionality and bacterial/fungal microbial diversity. However, according to the co-occurrence network of bacteria and fungi, soil multifunctionality was intimately correlated with the biodiversity of the main ecological clusters (modules) of bacteria and fungi, rather than to the entire soil microbial community structure. The keystone species of module hubs and connectors play critical roles in maintaining the stability of ecological clusters of microbial co-occurrence networks and linkages between ecological clusters. Soil pH is a major predictor of changes in plant biomass, and leads to changes therein by affecting the major ecological clusters of bacterial and fungal co-occurrence networks. These results suggested that SMS may serve as a good alternative to peat as a carrier of mineral-solubilizing microorganisms to maintain soil multifunctionality and promote plant growth.

Effect of MICP-recycled GFRP fiber on the self-repairing properties of concrete

The recycling of waste glass fiber-reinforced polymer (GFRP) holds paramount importance in realizing sustainability goals. This study aims to enhance the efficacy of fiber-reinforced self-healing concrete by employing recycled GFRP (rGFRP) fibers as carriers for Microbiologically Induced Calcite Precipitation (MICP). Preparations involved the development of pretreatment of rGFRP using microbial mineralization. Examination encompassed the assessment of interactions between microorganisms and fibers, microstructural characterization of self-healing specimens, and the strength of repaired specimens. This was conducted through the quantification of CaCO3 precipitation, strength tests, scanning electron microscopy (SEM), X-ray computed topography (CT) analysis, and mercury intrusion porosimetry (MIP). The results revealed that mineralized rGFRP fibers had little impact on the flexural and compressive strength of the reinforced mortar, while increased the tensile strength by up to 34.1 %. The mineralized rGFRP fiber-reinforced mortar achieved a repair rate of 84.5 % for cracks within 0.3 mm after 28 days of water curing. Comparatively, the mineralized rGFRP fiber bacterial mortar exhibited higher water absorption than its non-mineralized counterpart. Using untreated rGFRP fibers for self-healing can reduce the porosity and water absorption of the mortar to some extent, while adding mineralized rGFRP fibers for self-healing increased the crack area repair rate and also increased the porosity of the mortar. Therefore, using untreated rGFRP fibers as a carrier for microorganisms to repair mortar may present a more favorable choice. The results of this study will contribute to further improvement in the application of fiber-reinforced self-healing concrete in the engineering field.

Evaluation of the Efficacy of a Commonly Used Antiseptic Soap in Reducing the Bacterial Load on the Palms of Some Undergraduate Students of Alex Ekwueme Federal University Ndufu Alike Ikwo, Ebonyi State, Nigeria

Introduction: The human hand serves as a carrier of microorganisms, comprising both transient and normal flora. The present study aims at evaluating the efficacy of a commonly used antiseptic soap in reducing the bacterial load on the palms of some undergraduate students of Alex Ekwueme Federal University Ndufu Alike Ikwo, Ebonyi State. Methods: Handwashing with the antiseptic soap was carried out according to the World Health Organisation protocol on handwashing. Bacterial identification was done using morphological and biochemical characteristics, also antimicrobial susceptibility test was carried out on the identified bacterial species using agar diffusion according to the method of Clinical Laboratory Standard Institute. Results: The result of the bacterial load indicated bacterial load of 2.0×102 before handwashing and 0.96×102 after handwashing, on plate count agar and bacterial load of 7.7×101 before handwashing and 3.2×101 on MacConkey agar, the results were statistically analyzed using Chi-square test. The following bacteria species were identified from the palms of the students after handwashing; Strep. pneumoniae, Staph. aureus, Staph. spp, Strep. spp, A. baumannii, E. coli. Conclusion: The result of the statistical analysis showed that sanitol antiseptic soap significantly reduced the bacterial load on the palms of the participants.

Reviewing the role of microplastics as carriers for microorganisms in absorbing toxic trace elements.

The pervasive presence of microplastics in various settings, such as freshwater and marine ecosystems, has sparked serious concerns. Microplastics can operate as possible transporters for hazardous trace elements or microbes, even though they are not naturally able to actively absorb these compounds. The binding sites on the plastic's surface or the complexes that are formed with the organic material on the plastic are how this adsorption process takes place. Microplastics' surfaces also seem to be attractive to microorganisms, such as bacteria and algae. Microorganisms can adhere to the rough surface of microplastics, which facilitates their colonization and formation of biofilms. Numerous bacteria, including ones that have the ability to absorb hazardous trace elements, can be found in these biofilms. Microplastics and microbes can interact in ways that are advantageous and detrimental. Microplastics have the ability to act as a substrate for microbial growth, which could lead to an increase in the quantity of microorganisms in the surrounding environment. On the other hand, microplastics may make it easier for microbes to spread to new areas, which could help dangerous or deadly species proliferate. Research is still ongoing to determine the degree to which microplastics serve as carriers of microbes and hazardous trace elements. Comprehending the implications of microplastics, pollutants, and microorganisms in a variety of environmental conditions is difficult due to their complex interplay. This review provides a detailed description of the complexity of the problem and used the examples related to microplastics, its environmental effects, and impacts on human health.

Research Progress on the Removal of Contaminants from Wastewater by Constructed Wetland Substrate: A Review

Constructed wetlands (CWs) primarily achieve efficient wastewater purification through synergistic interactions among substrates, plants, and microorganisms. Serving as the structural foundation of the entire wetland system, substrates not only provide a growth medium for plants, but also serve as adhesive carriers for microorganisms and habitats for animal activities. Research on substrates has attracted considerable attention; however, in practical engineering applications, the selection of substrates often depend on personal experience, which may lead to significant gaps in the effectiveness of wetland systems in treating different characteristic contaminants. Therefore, it is of great significance to investigate the influence of substrates on the removal of contaminants in sewage and identify substrate materials with good physical and chemical properties to optimize the design and operation of CWs-based sewage-treatment systems and improve their purification efficiency. In this review, bibliometric analysis was conducted to using the Web of Science database and VOSviewer_1.6.20 software to assess the progress of research on CWs. This article provides a comprehensive overview of substrate types and characteristics based on recent research advancements in the field. Additionally, it discusses removal methods and the influence of factors related to conventional contaminants (COD, nitrogen, and phosphorus), heavy metals (HMs), fluorinated compounds, pharmaceuticals, personal care products (PPCPs), and microplastics. A thorough evaluation was conducted on the economic costs of various substrates and their ability to remove major contaminants from water bodies, providing a reference for the further development of wetland technology.

Study on Influence of Mechanical Properties of Concrete based on Microbe Supported in Slag

Concrete material with its own excellent properties, plays a vital role in the construction industry, the annual production of about 10 billion tons, which makes concrete become second only to water, the world's second largest amount of material. However, in the actual service process, all kinds of buildings will be affected by their own and environmental factors, concrete is easy to crack, which affects the mechanical properties of concrete decline, this paper in slag as a carrier of microorganisms on the basis of adding nano-SiO2 in ready-mixed concrete, studied its 3d, 7d, 14d, 28d compressive strength changes. The results show that the strength of concrete can be improved by adding the right amount of nano-SiO2. The addition of nano SiO2 can promote the hydration reaction of cement, resulting in more hydration gelling products of concrete, thus reducing the porosity of concrete and improving the compressive strength of concrete. The results of this study provide an important reference value for the practical application of microbial concrete self-healing.

Studies on airborne microbiota in Mexico, a review

Airborne microbiota has garnered increasing interest in recent decades, not only because of its role as carrier of pathogenic microorganisms and its involvement in the deterioration of man-made objects, buildings, and food but also because of its participation in atmospheric processes and its content of microorganisms, important for biogeochemical cycles in different ecosystems. In order to understand and comprehensively analyze existing studies on airborne microbiota in Mexico, a systematic review was conducted utilizing Web of Science and Google Scholar as search tools. The information found in the 35 identified publications was systematically organized, including title, study location, sampling method, laboratory approach, identification method, and organisms found. This information was then ordered into three sections: bibliometric analysis, employed methodologies, and main findings. Through this work, it was revealed that the studies were carried out in 14 out of the 32 states of Mexico, with Mexico City standing out with 17 articles. Three methodological approaches were identified: microbial cultures (77% of the studies), microscopy (11.5%), and metagenomics (11.5%). The studies predominantly focused on state capitals or densely populated cities, making the identification of potentially pathogenic organisms from humans, animals, and plants, of particular interest. This comprehensive review lays the foundation for proposing compelling avenues of future research, aimed at advancing our comprehension of airborne microbiota in Mexico.

The remediation of polycyclic aromatic hydrocarbon contaminated soil by immobilized microorganisms using distiller's grains.

Polycyclic aromatic hydrocarbons are a persistent organic pollutant, and their biodegradation in the soil is often limited due to the limited degradation ability of indigenous bacteria and the low activity of exogenous PAH degrading bacteria. Immobilized microbial technology can protect microorganisms from the impact of harsh environments, and distiller's grains have the potential as carriers for microbial immobilization. This study aims to use distiller's grains as a microbial carrier, investigate the feasibility of immobilized microorganisms using distiller's grains for remediation of PAH contaminated soil; explore the relationship between soil nutrient content, consumption, and PAH degradation rate; and reveal the mechanism of bioremediation from the perspective of soil enzyme activity and microbial community composition. The results showed that after 72 days of remediation, the removal rates of phenanthrene and pyrene in the treatment of immobilized microorganisms in distiller grains reached 91.78% and 58.59%, respectively. Distiller grains can serve as a carrier for microorganisms, providing them with shelter and nutrients to enhance their chance of survival. Additionally, they can regulate the composition of soil particles and improve aeration, thereby increasing the efficiency of PAH degradation in soil.

SiO2 and microparticle transport in a saturated porous medium: effects of particle size and flow rate

SiO2 and polystyrene (PS) are carriers of microorganisms and metals in porous media, which can produce changes in groundwater quality and cause issues related to clogging of the porous medium. Although SiO2 and PS particle transport in porous media has been previously studied, what influences transport at various particle sizes and flow rates remains unclear. Here, we looked at how pH and ionic strength affected the surface zeta potentials as well as how particle size and flow rate affected the transport of suspended SiO2/PS particles in a porous media. The results indicate that increasing pH and decreasing ionic strength increased the negative surface charges on both the SiO2 and PS particles, thereby yielding greater electrostatic repulsion between particles. At the same flow rate, the retention rate of 10 μm PS particles in the porous medium was 46.1% better than that of 2 μm particles, whereas the retention rate of 10 μm SiO2 particles was 7.88% better than that of 2 μm particles. For the same particle size, increasing the flow rate decreased SiO2 and PS retention in the porous medium. Thus, particle size and flow rate substantially impact the transport of SiO2 and PS-suspended particles in a porous media.

Human in vivo assessment of the survival and germination of Heyndrickxia coagulans SNZ1969 spores delivered via gummy candies

Confectionary products hold promise as unconventional food carriers for probiotic microorganisms. This study explored the delivery of Heyndrickxia coagulans SNZ1969, a spore-forming probiotic, using gummy candies. In this study, we prepared gummy candies containing bacterial spores with a viable count that remained stable during a 24-month shelf-life period, meeting the label claim of at least one billion CFUs per serving (24 g). Then, we carried out an intervention trial involving 24 healthy adults who consumed one serving per day for two weeks followed by an additional two weeks of follow-up. Fecal samples were collected and analyzed with a protocol that allowed the viable counts of SNZ1969, both in spore and vegetative forms. The obtained results revealed that bacterial spores germinated in all volunteers. SNZ1969 persistence in the gut was monitored for two weeks after the end of gummy candy consumption, indicating its potential for prolonged colonization. These findings highlight the potential of unconventional food carriers for probiotic delivery and suggest that spore-forming probiotics can be metabolically active in the human intestine. These findings provide information for the development of food products containing spore-forming probiotics and their potential benefits in promoting gastrointestinal health.

A review of fermented milks: potential beneficial effects on human nutrition and health.

Fermented dairy products are formed during the acidification of milk through fermentation by suitable microorganisms; it contains different microorganisms in sufficient numbers and in an active state. A wide range of fermented milk products are produced and consumed around the world, including yogurt, kefir, koumiss, and yogurt beverages. There are various health benefits associated with the consumption of fermented dairy. Many studies reported that some fermented milk products have antimicrobial, antimutagenic, anticarcinogenic, and antihypertensive properties as well as provide benefits on mineral metabolism, reduce lactose intolerance symptoms and cholesterol levels. In addition to these effects, it has many other beneficial effects such as positive effects on type 2 diabetes and hypertension, antimutagen and antioxidant effects, and reduction of allergic symptoms. Dairy products including fermented milk are known to be the main carrier of probiotic microorganisms, and many clinical studies show the effects of probiotic strains on health. In this study, the effects of fermented milks on human nutrition and health are mentioned.

The Importance of the Targeted Design of Biochar Physicochemical Properties in Microbial Inoculation for Improved Agricultural Productivity—A Review

Biochar has great potential as a soil conditioner and as a carrier of beneficial microorganisms that support the removal of pollutants, influence the circulation of nutrients, and support plant growth. This review summarizes and discusses factors shaping the physicochemical properties of biochar, including feedstock, pyrolysis conditions, and accompanying processes used as post-pyrolysis modification to improve the functionality of biochar. Key physical and chemical properties such as high porosity and specific surface area, nutrient content, pH, and biochar functional groups are discussed in detail to show biochar’s potential as a carrier for microorganisms. This review also discusses and summarizes biological indicators that allow for assessing the quality and efficiency of the microbiological modifiers. Finally, this paper presents the benefits and limitations of biochar application to agriculture and provides recommendations for future research to improve the quality and expand the applicability of biochar-based inoculants.

Comparative Spectral Analysis of Octopus vulgaris Cuvier, 1797, Jellyfish and Seawater from Aegean Sea, Evia, Greece

Research was conducted using the Fourier Transform Infrared (FTIR) spectral spectroscopy method on octopus, jellyfish, and seawater from the Aegean Sea, Chalkida, Evia Island, Greece. Our analyses of two peaks at 896 and 933 cm-1 indicate their presence in the octopus. These peaks are expressed in Martian minerals and meteorites. The results suggest that the octopus is adaptable to conditions on another planet. Our data provide a basis for speculating that it is an organism from Mars or another planet with similar characteristics. However, the spectral characteristics of the jellyfish and seawater do not correspond to the spectral characteristics of Martian minerals and meteorites. Studies have been conducted also on the microbial flora on the skin of octopus of the species Octopus vulgaris Cuvier, 1797, captured in the Aegean Sea near Chalkida, Greece, on the island of Euboea (Evia). The aim was to assess their role as carriers of pathogenic microorganisms. Bacteria from the families Micrococcaceae and Enterobacteriaceae have been isolated, as well as Aeromonas hydrophilia ssp. hydrophilia, Enterococcus caseiflavus, and Candida lusitaniae. Staphylococci prevail, with the highest quantity being Staphylococcus simulans (107.67 + 10.21 CFU cm-2 on the head and 67.33 + 6.02 CFUcm-2 on the tentacles), followed by Staphylococcus piscifermentans (14.33+1.69 CFU cm-2 on the head and 37.33+1.25 CFU cm-2 on the tentacles) and Staphylococcus hyicus (3.67+1.25 CFU cm-2 on the head and 14.67 + 3.39 CFU cm-2 on the tentacles). Among the Gram-negative bacteria, Aeromonas hydrophilia ssp. hydrophilia piscifermentans predominated, found only on the head of octopuses at 9.67+2.05 CFU cm-2, followed by Klebsiella pneumoniae ssp. ozaenae, also isolated solely from the head (4.00+1.63 CFU cm-2). Escherichia coli was the least prevalent, but it was detected both on the head (2.67+0.47 CFU cm-2) and the tentacles of the studied animals (1.67+0.47 CFU cm-2). Enterococci and fungi were isolated in small quantities from the octopuses' heads and tentacles. The isolated bacteria demonstrated in vitro resistance to most of the tested antibiotics. They were only sensitive to broad-spectrum agents such as amphenicols, tetracyclines, aminoglycoside-aminocyclitols (excluding kanamycin), and quinolones. Staphylococci also showed sensitivity to some penicillins (ampicillin, amoxicillin). However, lincosamides (clindamycin) were ineffective in vitro against the studied bacteria. Potentiated sulfonamides exhibited high activity against the Gram-negative bacteria but not against Gram-positive ones.Aeromonas hydrophila is known to be pathogenic to marine inhabitants, including octopuses. S. simulans, E. coli, and K. pneumoniae are conditionally pathogenic to animals and humans. Their presence on the surface of the studied octopuses, especially E. coli, could indicate seawater fecal contamination and possibly other pathogenic species. The current results also reveal the distribution of multidrug-resistant bacterial strains, even among bacteria that are representatives of the normal microflora of octopuses.

Study on the biodegradation of phenol by Alcaligenes faecalis JH1 immobilized in rice husk biochar

Immobilized microbial technology is a sustainable solution to reduce water pollution. Understanding the microorganisms in immobilized biochar is critical for the removal of contaminants in water. Biochar as a carrier of microorganisms, there are some problems need to be focused on, microporous structure blockage limiting the contact between microorganisms and pollutants for further degradation, unstable microbial loading, and low cycle times. To solve these problems, Alcaligenes faecalis was immobilized with rice hull biochar to study its adsorption and degradation characteristics of phenol. It was found that A. faecalis JH1 could effectively remove 300 mg/L of phenol within 24 h. The adsorption capacity of rice husk biochar for phenol increased with the increasing pyrolysis temperature (700 > 500>300°C). The immobilized biomass of JH1 from 700°C rice husk biochar reached 249.45 nmol P/g at 24 h of fixation reaction. It was found that the phenol removal rate of JH1 immobilized at all temperature biochar reached 300 mg/L within 12 h after the sixth cycle. As the number of cycles increased, bacteria grew and adhered to the biochar, forming a thick viscous biofilm and accelerating the removal of phenol. The results showed that A. faecalis could firmly adhere to rice hull biochar and degrade phenol effectively, with good durability and cyclicity.

Petroleum hydrocarbon degradation of husk biochar product carrying biofilm-forming bacteria

Environmental pollution problems caused by petroleum and its derivatives such as polycyclic aromatic hydrocarbons (PAHs) has remarkably increased and become a major global threat to human health and ecological equilibrium, resulting in a crucial need for remediation. Recently, in order to solve this problem, biofilm is one of the biodegradation approaches which could degrade and transform oil components effectively. Moreover, to enhance the petroleum hydrocarbons removal efficiency and easy to apply in any place bio-carriers, biochar was used to attach biofilm-forming microorganisms. Biochar is not only used as a carrier for microorganisms but also a source of substrates to help absorb a part of aromatic compounds. Therefore, in this investigation, we used the mixture of multiple petroleum-degrading and biofilm-forming bacterial strains immobilized on husk biochar to create an oil-degrading product. The ability of oil-degrading bacteria immobilized on biochar, planktonic bacteria and biochar without bacteria on the elimination of total petroleum hydrocarbons and several aromatic hydrocarbons was investigated. The results indicated that using husk biochar as a carrier for biofilm-forming bacteria to attach on could considerably enhance the removal efficiency of oil components. At 50 kg/batch scale, the formed product could remove 99% of total petroleum hydrocarbons with the initial amount of 4.786 mg/l and over 96% of aromatic hydrocarbons including anthracene, naphthalene, phenanthrene and pyrene with the initial amount of 250 mg/l. The obtained product is porous, black, with particle size of 1-3 mm, cell density of ≥ 109 CFU/g(ml), stable for use ≥ 6 months and safe for the environment. In general, the obtained results highpoint the great possible of applying this product in the treatment of oil contaminated soil and water.

Fermented grain-based beverages as probiotic vehicles and their potential antioxidant and antidiabetic properties

This work aimed to determine the most adequate combinations of germinated or non-germinated grains (lentils, brown rice, and sorghum) as substrates for fermentation by Saccharomyces boulardii with the goal of producing functional beverages as probiotic carriers. Additionally, the antioxidant and antidiabetic potentials of the beverages were investigated. The binary mixture of lentils (50%) and brown rice (50%) proved to be the most favorable combination for S. boulardii growth, achieving 10.01 and 12.36 log CFU mL−1 for fermented beverages obtained using non-germinated and germinated grains, respectively. This combination also yielded products with superior antioxidant properties, measuring 470.85, 1286.50 and 370.27 μmol TE mL−1 for DPPH, ABTS and FRAP, respectively, for fermented beverages produced from the non-germinated grains. Concerning antidiabetic properties, fermented beverages produced using non-germinated grains of brown rice, sorghum and the mixture of lentil and brown rice in equal proportions deserve special mention, as they reduced α-amylase activity by 74.67, 59.25 and 51.23%, respectively, compared to their respective non-fermented samples. In conclusion, fermentation with S. boulardii using different grains as substrates proved to be an excellent strategy for obtaining beverages with improved antioxidant and antidiabetic properties, as well as serving as effective carriers for probiotic microorganisms.

Understanding the transcriptomic response of Lactiplantibacillus pentosus LPG1 during Spanish-style green table olive fermentations.

Lactiplantibacillus pentosus (Lbp. pentosus) is a species of lactic acid bacteria with a great relevance during the table olive fermentation process, with ability to form non-pathogenic biofilms on olive epidermis. The objective of this work is to deepen into the genetic mechanisms of adaptation of Lpb. pentosus LPG1 during Spanish-style green table olive fermentations, as well as to obtain a better understanding of the mechanisms of adherence of this species to the fruit surface. For this purpose, we have carried out a transcriptomic analysis of the differential gene expression of this bacterium during 60 days of fermentation in both brine and biofilms ecosystems. In brines, it was noticed that a total of 235 genes from Lpb. pentosus LPG1 were differentially expressed during course of fermentation and grouped into 9 clusters according to time-course analysis. Transport and metabolism of carbohydrates and amino acids, energy production, lactic acid and exopolysaccharide synthesis genes increased their expression in the planktonic cells during course of fermentation. On the other hand, expression of genes associated to stress response, bacteriocin synthesis and membrane protein decreased. A total of 127 genes showed significant differential expression between Lpb. pentosus LPG1 planktonic (brine) and sessile (biofilms) cells at the end of fermentation process (60 days). Among the 64 upregulated genes in biofilms, we found genes involved in adhesion (strA), exopolysaccharide production (ywqD, ywqE, and wbnH), cell shape and elongation (MreB), and well as prophage excision. Deeping into the genetic bases of beneficial biofilm formation by Lpb. pentosus strains with probiotic potential will help to turn this fermented vegetable into a carrier of beneficial microorganisms to the final consumers.

Swimming pool policies for carriers of highly-resistant micro-organisms receiving rehabilitation care in the Netherlands

Swimming pool policies for carriers of highly-resistant micro-organisms receiving rehabilitation care in the Netherlands

A Two-Mediator System Based on a Nanocomposite of Redox-Active Polymer Poly(thionine) and SWCNT as an Effective Electron Carrier for Eukaryotic Microorganisms in Biosensor Analyzers.

Electropolymerized thionine was used as a redox-active polymer to create a two-mediated microbial biosensor for determining biochemical oxygen demand (BOD). The electrochemical characteristics of the conducting system were studied by cyclic voltammetry and electrochemical impedance spectroscopy. It has been shown that the most promising in terms of the rate of interaction with the yeast B. adeninivorans is the system based on poly(thionine), single-walled carbon nanotubes (SWCNT), and neutral red (kint = 0.071 dm3/(g·s)). The biosensor based on this system is characterized by high sensitivity (the lower limit of determined BOD concentrations is 0.4 mgO2/dm3). Sample analysis by means of the developed analytical system showed that the results of the standard dilution method and those using the biosensor differed insignificantly. Thus, for the first time, the fundamental possibility of effectively using nanocomposite materials based on SWCNT and the redox-active polymer poly(thionine) as one of the components of two-mediator systems for electron transfer from yeast microorganisms to the electrode has been shown. It opens up prospects for creating stable and highly sensitive electrochemical systems based on eukaryotes.

Bacterial Contamination of Collected Cockroaches and Determination Their Antibiotic Susceptibility in Khorramabad City, Iran.

Cockroaches are one of the most important carriers of pathogenic microorganisms. Therefore, the presence of cockroaches in public places, especially in hospitals, homes, and restaurants, is dangerous, and threatens the health of society, people, and the environment. The aim of this study was evaluation of bacterial contamination of cockroaches and the sensitivity of these bacteria to various antibiotics, captured from Khorramabad City, Iran. This descriptive cross-sectional study was performed on 150 cockroaches collected from hospital environments, homes, and restaurants in Khorramabad. The outer surface of the cockroaches was washed with physiological saline. The suspension was centrifuged for 5 minutes at 2000rpm. Isolation and identification of bacteria was performed using phenotypic methods. Antibiotic susceptibility testing was performed by disk diffusion method according to Clinical and Laboratory Standard Institute (CLSI) guideline. A total of 100 American cockroaches (66.66%), 28 B. germanica (18.66%) and 22 Blatta orientalis (14.66%) were identified. In total, 97.33% of the collected cockroaches were infected with bacteria. The most bacterial infection of the cockroaches was Escherichia coli, coagulase-negative Staphylococci and Bacillus respectively. The overall results of the antibiogram test showed that the identified bacteria were resistant to cephalothin, ampicillin, cefotaxime, and kanamycin antibiotics, semi-sensitive to ciprofloxacin and sensitive to tetracycline, gentamicin, nitrofurantoin, Trimethoprim/sulfamethoxazole, and Chloramphenicol. Infection of cockroaches with pathogenic bacterial agents in hospital, residential, and restaurant environments, as well as the observation of bacterial resistance to some common antibiotics is worrying.