Distribution of pathogenic bacteria and antimicrobial sensitivity of eye infections in Suzhou

AIM:To investigate the types of bacteria in patients with eye infections in Suzhou and their drug resistance to commonly used antibacterial drugs.METHODS:The clinical data of 155 patients were retrospectively collected in this study,and the pathogenic bacteria species and drug resistance of each pathogenic bacteria were analyzed.RESULTS:Among the 155 patients(age from 12 to 87 years old,with an average age of 57,99 males and 56 females)with eye infections(160 eyes:74 in the left eye,76 in the right eye and 5 in both eyes,all of which were exogenous),71(45.81%)strains were gram-positive bacteria,23(14.84%)strains were gram-negative bacteria and 61(39.35%)strains were fungi.Gram-positive bacteria were highly resistant to penicillin and erythromycin(78.87%and 46.48%respectively),but least resistant to vancomycin at 0.Gram-negative bacteria were highly resistant to cefoxitin and compound sulfamethoxazole(100%and 95.65%respectively),but least resistant to meropenem at 0.Comparison of the resistance of gram-positive and gram-negative bacteria to some drugs revealed statistically significant differences(P<0.05)in the resistance of both to cefoxitin,cotrimoxazole,levofloxacin,cefuroxime,ceftriaxone and ceftazidime,and both had higher rates of resistance to gram-negative bacteria than to gram-positive bacteria.The distribution of bacterial infection strains showed that Staphylococcus epidermidis was the most common strain in the conjunctiva,cornea,aqueous humor or vitreous body and other eye parts.Besides,Fusarium and Pseudomonas aeruginosa were also among the most common strains of conjunctival and corneal infections.CONCLUSION:Gram-positive bacteria are the dominant bacteria in eye infections,followed by gram-negative bacteria and fungi.Considering the resistance of gramnegative bacteria to multiple drugs,monitoring of bacteria should be strengthened in eye bacterial infections for effective prevention and control to reduce complications caused by eye infections.

Antiseptic Efficacy of A Soap Made from Biosurfactants Isolated from Bacillus and Lactobacillus against Pathogenic Bacteria

The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological techniques (30 Bacillus and 30 Lactobacillus) and the ability to produce biosurfactants was demonstrated by a hydrocarbon emulsification index (E24). The emulsification indexes (E24) varied from 9% to 100% for Bacillus and from 33% to 100% for Lactobacillus as well. The antagonistic assay showed that biosurfactants were able to inhibit the formation of biofilms and growth of pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhirium, Shigella boydii and Proteus mirabilis. The biosurfactant consortium (BioC) from Bacillus consortium and from Lactobacillus was able to inhibit biofilm formation and the pathogens growth. The BioC was stable to alkaline pH and the temperatures stability of Biosurfactant was ranging from 50°C to 90°C. The soap was made by the cold saponification process using one biosurfactant consortium formulated. This soap has a pH of 10 and showed good cleaning power and good foam stability. Similarly, the soap showed good antiseptic power and disinfection power against all pathogens tested. Handwashing is critical to preventing disease transmission. The persistence of pathogens in waste water was evaluated. The BioS produced showed good disinfection power against all pathogens tested. The valor of reduction on the hands and in the waste water was significantly more than compared to the control soaps used. This soap could be used in the prevention, fighting, and treatment of bacterial and viral infections.

Survival of pathogenic bacteria in compost with special reference to Escherichia coli

Application of compost in agricultural practice could potentially cause contamination of foodstuffs with pathogenic bacteria such as Escherichia coli O157：H7 （E. Coli O157）. We investigated pathogenic bacteria in compost collected from the compost facilities, and evaluated the survival of E. coli K12 and O157 in laboratory experiments. Out of 19 compost product samples, coliform bacteria and salmonella were detected in 7 and 3 samples respectively. The number of coliform bacteria was 1.8 × 10^2 to 2.5 × 10^6 CFU/g dw and that of salmonella was 4.2 × 10^1 to 6.0 × 10^3 CFU/g dw. Moreover. coliform bacteria, fecal coliform, E. coli and salmonella were detected during composting at 54℃ to 67℃. The results indicated that moisture content was a very important factor to the heat sensitivity of pathogenic bacteria in compost, E. coli in compost of high moisture content was more sensitive than that in compost of low moisture content, cells harvested in logarithmic phase was more sensitive than these in stationary phase, and E. coli K12 was more sensitive than E. coli O157. Based on the D values, the lethal time of E. coli K12 and 0157 from 10^8 to 10^0 CFU/g dw were 16.3 and 28.8 min, respectively, at 60℃ in compost with 40% moisture content. However, some E. coli cells survived in composting process at 54℃ to 67℃. Water potential（low moisture content） and physiological aspects of bacteria（stationary phase） could explain only in part of the prolonged survival of E. coli in compost, and there should be some other factors that are conducive to bacterial survial in compost.

Studies on the edwardsiellosis and characterization of pathogenic bacteria from diseased flounder (Paralichthys olivaceus L.) and turbot (Scophthalmus maximus L.)

Edwardsiellosis of flounder and turbot occurring in different mariculture farms during 2001～ 2004 was examined, including the conditions of disease occurrence, clinical signs and pathological changes. The results showed that all diseased fishes expressed bacterial septicaemia. A total of 148 strains were identified using a combination of traditional physiological and biochemical tests and partial 16S rRNA gene analysis. In addition, the mole fraction G ＋ C ratio of the DNA of representative strain of isolates and serum homology were detected, and pathogenicity tests of isolates were conducted by experimental infection. The results revealed that 148 strains were identified as E. tarda of genus Edwardsiella, all the isolates are of serologic similarity, and have strong pathogenicity to flounder and turbot.

Distribution and drug resistance of pathogenic bacteria isolated from cancer hospital in 2013

Objective： To understand distribution and drug resistance of pathogenic bacteria from a specialized cancer hospital in 2013 in order to provide a basis for rational clinical antimicrobial agents. Methods： Pathogenic bacteria identification and drug sensitivity tests were performed with a VITEK 2 compact automatic identification system and data were analyzed using WHONET5.6 software.Results： Of the 1,378 strains tested, 980 were Gram-negative bacilli, accounting for 71.1%, in which Klebsiella pneumonia, Escherichia coli and Pseudomonas aeruginosa were the dominant strains. We found 328 Gram-positive coccus, accounting for 23.8%, in which the amount of Staphylococcus aureus was the highest. We identified 46 fungi, accounting for 4.1%. According to the departmental distribution within the hospital, the surgical departments isolated the major strains, accounting for 49.7%. According to disease types, lung cancer, intestinal cancer and esophagus cancer were the top three, accounting for 20.9%, 17.3% and 14.2%, respectively. No strains were resistant to imipenem, ertapenem or vancomycin.Conclusions： Pathogenic bacteria isolated from the specialized cancer hospital have different resistance rates compared to commonly used antimicrobial agents; therefore antimicrobial agents to reduce the morbidity and mortality of infections should be used.

Functional identification of phenazine biosynthesis genes in plant pathogenic bacteria Pseudomonas syringae pv. tomato and Xanthomonas oryzae pv. oryzae

Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato （Pst） DC3000 and Xanthomonas oryzae pv. oryzae （Xoo） PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-l-carboxylic acid （PCA） of Pst DC3000 accumulated to 13.4 IJg L-1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL-1 PCA, while Xoo PXO99A was sensitive to 50 IJg mL ~ PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.

Synergistic Effect of Combined Antibiotics against Some Selected Multidrug Resistant Human Pathogenic Bacteria Isolated from Poultry Droppings in Akure, Nigeria

Antibiotic resistant bacteria pass between humans, between animals and between humans and animals in both directions, the use of antibiotics in poultry has contributed to multiple antibiotic resistant in pathogenic bacteria and use of two antibiotics might prevent the emergence of resistance to either. In this study, synergistic effect of combined antibiotics against multidrug resistant human pathogenic bacterial isolates from poultry droppings in Akure, Nigeria was examined. Collection of samples, isolation and identification of bacteria were carried out using standard microbiological method, antibiotic sensitivity test was performed by disc diffusion method and zone of inhibition was used to interpret the sensitivity test as resistant, susceptible or intermediate while combined effects of two antibiotics were investigated by macrobroth dilution and checkerboard assay methods while the synergetic effects of combined antibiotics were calculated using Fractional Inhibitory Concentration (FIC) and percentage synergistic interaction was calculated. All the ten (10) species of bacterial isolates were multidrug resistant and are less resistant to ofloxacin. The highest percentage synergistic interactions observed were Ofloxacin + Amoxicillin (90%), Ciprofloxacin + Amoxicillin (90%), Tetracycline + Amoxicillin (70%), Tetracycline + Augmentin (80%), Cotrimoxazol + Amoxicillin (50%), Cotrimoxazol + Augmentin (70%), Chloramphenicol + Amoxicillin (70%) and Chloramphenicol + Augmentin (80%). Poultry droppings is a potential source of human pathogenic bacteria, high frequency of multiple antibiotic resistance bacteria observed in this study is of great treat to man as this may cause the treatment of infection caused by these bacteria to be difficult. Combination of beta-lactam antibiotic with fluoroqunolones, tetracycline, Chloramphenicol and Cotrimoxazole was synergetic and this will reduce dose related toxicity and prevent resistance to single antibiotic.

Fluorescent antibiotics for real-time tracking of pathogenic bacteria

The harm of pathogenic bacteria to humans has promoted extensive research on physiological processes of pathogens,such as the mechanism of bacterial infection,antibiotic mode of action,and bacterial antimicrobial resistance.Most of these processes can be better investigated by timely tracking of fluorophore-derived antibiotics in living cells.In this paper,we will review the recent development of fluorescent antibiotics featuring the conjugation with various fluorophores,and focus on their applications in fluorescent imaging and real-time detection for various physiological processes of bacteria in vivo.

Rapid label-free SERS detection of foodborne pathogenic bacteria based on hafnium ditelluride-Au nanocomposites

Two-dimensional(2D)nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features.Herein,2D hafnium ditelluride(HfTe_(2)),a new member of transition metal tellurides,is exploited to support gold nanoparticles fabricating HfTe_(2)-Au nanocomposites.The nanohybrids can serve as novel 2D surface-enhanced Raman scattering(SERS)substrate for the label-free detection of analyte with high sensitivity and reproducibility.Chemical mechanism originated from HfTe_(2) nanosheets and the electromagnetic enhancement induced by the hot spots on the nano-hybrids may largely contribute to the superior SERS effect of HfTe_(2)-Au nanocomposites.Finally,HfTe_(2)-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bac-teria,which realize the rapid and ultrasensitive Raman test of Escherichia coli,Listeria mono-cytogenes,Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to 1.7×10^(8).Combined with principal component analysis,HfTe_(2)-Au-based SERS analysis also completes the bacterial classification without extra treatment.

Antibacterial activity of plant extracts in different solvents against pathogenic bacteria: An in vitro experiment

Objective:To assess the antibacterial activity of 5 selected plants against 4 pathogenic bacteria.Methods:Three solvents with different polarities were used to extract antimicrobial agents from the plants via maceration technique.The agar-disc diffusion technique was adopted to primarily screen antibacterial activities.Broth-dilution assay was employed to determine the minimum inhibitory concentration(MIC)and the minimum bactericidal concentration(MBC).Results:Among all extracts,the ethanol extract of Piper betle Linn showed the highest antibacterial activity against Gram-positive and the negative bacteria.MIC and MBC of the ethanol extract of Piper betle Linn against Salmonella typhimurium were the same(1?562.50 mg/L);while it showed the highest MIC and MBC against Pseudomonas aeruginosa of 6?250 mg/L and 12?500 mg/L,respectively.Conclusions:Salmonella typhimurium is the most susceptible bacteria while Pseudomonas aeruginosa is the most resistant bacteria towards the ethanol extract of Piper betle Linn.Piper betle possesses compounds with potential antibacterial activity and might be useful as an alternative to control infectious diseases.

Species Identification of Mealie Meal Spoilage Organisms and Pathogenic Bacteria from Selected Food Stores in Lusaka District of Zambia

Background: Mealie Meal is one of the by-products of maize from dry milling. It constitutes more significant part of the daily diet of growing population of the Lusaka District of Zambia. However, reported cases of a cholera outbreak in October 2017-May 2018 were attributed to water contamination in the households of Lusaka. Hitherto there is no previous study or documented data for gastroenteritis caused by microbial contamination from food stores. Aim: The main objective of the study was to carry out species identification of Mealie meal spoilage organisms and pathogenic bacteria from selected food stores in Lusaka district from September 2019-March 2020. Crosssectional survey was conducted for food spoilage organisms and pathogenic bacteria of packaged maize meal flour from a selected food store. The number of packaged Mealie meal samples from selected food stores included in the study was 143 samples. Samples were obtained by a simple stratified random selection from food stores in Lusaka District. Thus Mealie Meal samples bought from Street food vendors were 96 (67%), Shops—30 (21%), Malls—17 (11.9%). Subsequently isolation by spread and pour plate methods, and species identification of microbial contamination by Cell Culture processes coupled to microbial morphological and biochemical characterization was performed. Microsoft Office Excel (version 2007) Spreadsheet was employed for the categorical data analysis and summarized graphical presentation of data. Laboratory findings revealed: Spoilage organisms—Aspergillum species, Mucor Species, Candida Species, Clostridium Species and Bacillus Species;Pathogenic Bacteria Species—Clostridium perfringens, Staphylococcus aureus, Clostridium tetani, Bacillus, Escherichia coli, Pseudomonas aeruginosa and Yesinia pestis. It can be established from the laboratory results earlier mentioned that the food poisoning outbreak could evolve from food stores in Lusaka district apart from water contamination.

Effect of Chinese Herbal Medicine on Pathogenic Bacteria of Cow Mastitis

[Objective]The paper was to analyze the clinical therapeutic effects of Chinese herbal medicine on pathogenic bacteria of cow mastitis.[Method]Eight Chinese herbs and three compound extracts were selected for the treatment of cow mastitis.Four kinds of pathogenic bacteria were successfully isolated from cows with mastitis by flat perforation irrigation method and tube double dilution method.In addition,in vitro antibacterial test was carried out,and in vitro inhibitory effects of single and compound Chinese medicine extracts on pathogenic bacteria causing cow mastitis were studied.[Result]A total of seven Chinese herbs had good inhibitory effect,such as Taraxacum mongolicum,Viola yedonensis and Polygala japonica,which received good effect of activating blood circulation and removing blood stasis,clearing away heat and toxic materials.[Conclusion]As good Chinese herbal medicines,T.mongolicum,V.yedonensis and P.japonica could be popularized.

Phytochemical Determination and Antibacterial Activity of Punica granatum Peel Extracts against Plant Pathogenic Bacteria

Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control agent for plant pathogenic bacteria. P. granatum peel was successfully extract using n-hexane, methanol and ethyl acetate by maceration. The highest yield obtained by ethyl acetate showed that ethyl acetate extracted more compounds that readily soluble to methanol and n-hexane. For in-vitro antibacterial activity, three different species of plant pathogenic bacteria were used namely Erwinia carotovorum subsp. Carotovorum, Ralstonia solanacearum, and Xanthomonas gardneri. For all crude extracts, four different concentrations 25, 50, 100 and 200 mg/ml were used in cup-plate agar diffusion method. Streptomycin sulfate at concentration 30 μg/ml was used as positive control while each respective solvent used for peel extraction was used as negative control. The results obtained from in vitro studies showed only ethyl acetate extract possessed antibacterial activity tested on the plant pathogenic bacteria. Methanol and n-hexane did not show any antibacterial activity against plant pathogenic bacteria selected where no inhibition zones were recorded. R. solanacearum recorded the highest diameter of inhibition zones for all range of concentrations introduced followed by E. carotovorum subsp. Carotovorum and X. gardneri. For the minimum inhbitory concentration (MIC) and minimum bactericidal concentration (MBC), only the ethyl acetate extract was subjected to the assay as only ethyl acetate extract exhibited antibacterial activity. The minimum concentration of ethyl acetate extract that was able to inhibit plant pathogenic bacteria was recorded at a concentration of 3.12 mg/ml which inhibited R. solancearum and E. carotovorum subsp. Carotovorum, followed by X. gardneri at concentration 6.25 mg/ml. For the minimum bactericidal concentration (MBC), the results showed that at the concentration of 12.5 mg/ml, the extract was still capable of killing the pathogenic bacteria, R. solanacearum, and P. caratovora sub.sp. caratovora while for the bacteria X. gardneri, the concentration that was able to kill the bacteria was 25 mg/ml. The qualitative estimation of phytochemical constituents within P. granatum L. ethyl acetate peel extracts had revealed the presence of tannins, flavonoids, phenols alkaloid, Saponins, and terpenoids. This study has demonstrated that Ethyl Acetate peel extracts of P. granatum has significant antibacterial activity against pathogenic plant bacterial, and it could be of high agricultural value.

Analysis on Distribution and Drug Resistance of Pathogenic Bacteria in ICU Patients with Nosocomial Infection from 2019 to 2021

Objective:To understand the pathogenic bacteria isolated from patients and their drug resistance changes in general ICU of the Affiliated Hospital of Hebei University,so as to provide reference for appropriate selection of antibiotics in clinical practice.Methods:A retrospective investigation was conducted to analyze the bacteriological distribution and drug resistance of nosocomial pathogens isolated from the specimens of hospitalized patients in the comprehensive ICU of the hospital from 2019 to 2021.The US technology BD Phoenix 100 automatic bacterial identification analyzer was used for bacterial identification of the pathogen samples,disk diffusion method was used for drug susceptibility test,and SPSS 22.0 software was used to analyze the trend of drug resistance.Results:A total of 970 strains of nosocomial pathogens were detected in the three years.The main pathogens were Acinetobacter baumannii(133 strains,13.71%),Klebsiella pneumoniae(106 strains,10.93%),Pseudomonas aeruginosa(83 strains,8.56%),Escherichia coli(76 strains,7.84%)and Enterococcus faecium(69 strains,7.11%).The resistance rate of Acinetobacter baumannii to antibiotics was high.Klebsiella pneumoniae,Pseudomonas aeruginosa and Escherichia coli had low resistance rates to carbapenems.The situation of bacterial drug resistance is still serious.Conclusion:The drug resistance of pathogenic bacteria collected from Class III Grade A Hospital’s patients to antibiotics was generally high.Therefore,clinical departments should strengthen the inspection of specimens of infection and drug sensitivity test in order to grasp the resistance mechanisms and drug resistance of pathogenic bacteria changes,and select appropriate antimicrobial agents according to the test results.Besides,the formation of drug-resistant strains also needs to be prevented,and the treatment of patients with severe infection needs to be improved.

Occurrence of viable but non-culturable(VBNC)pathogenic bacteria in tap water of public places

Viable but non-culturable(VBNC)bacteria have been detected in source water and effluent of drinking water treatment processes,leading to significant underestimation of viable cell counts.Limited information exists on VBNC bacteria in tap water,particularly in public places.To address this gap,a comprehensive nine-month study was conducted in a major city in south-eastern China,using culture-based and quantitative PCR with propidium monoazide(PMA)dye methods.Forty-five samples were collected from five representative public places(railway station,campus,hospital,shopping mall,and institution).The findings revealed that culturable bacteria represented only 0–17.51%of the viable 16S rRNA genes,suggesting that the majority of viable bacteria existed in an uncultured or VBNC state.Notably,opportunistic pathogens such as Escherichia coli,Enterococcus faecalis,Pseudomonas aeruginosa,Salmonella sp.,and Shigella sp.were primarily detected as VBNC cells,with concentrations ranging from 1.03×10^(0)to 3.01×10^(3),1.20×10^(0)to 1.42×10^(2),1.32×10^(0)to 8.82×10^(0),1.00×10^(0)to 6.71×10^(1),and 2.07×10^(0)to 1.93×10^(2)cell equivalent/100 mL,respectively.Culturable P.aeruginosa was observed in tap water after prolonged stagnation,indicating potential risks associated with bacterial regrowth.Spatial and temporal factors accounted for 17.1%and 26.0%,respectively,of the variation in tap water community structure during the sampling period,as revealed by 16S rRNA amplicon sequencing.This study provides quantitative insights into the occurrence of VBNC bacteria in tap water and highlights the need for more sensitive monitoring methods and microbial control techniques to enhance tap water safety in public locations.

Comparative study of heavy metal and pathogenic bacterial contamination in sludge and manure in biogas and non-biogas swine farms

The objective of this study is to determine and compare the heavy metal（Zn,Cu,Cd,Pb） and bacterial（E.coli,coliform and Salmonella spp.） contamination between swine farms utilizing biogas and non-biogas systems in the central part of Thailand.Results showed that average levels of E.coli,coliform,BOD,COD,Zn,Cu and Pb in sludge from the post-biogas pond were higher than the standard limits.Moreover,the levels of E.coli,coliform,Cd and Pb were also higher than the standard limits for dry manure.The levels of E.coli,coliform and BOD on biogas farms were lower than on non-biogas farms.Following isolation of Salmonella spp.,it was found that Salmonella serovars Rissen was the most abundant at 18.46%（12/65）,followed by Anatum 12.31%（8/65）,and Kedougou 9.23%（6/65）.The pathogenic strains of Salmonella serovars Paratyphi B var.java and Typhimurium were present in equal amounts at 4.62%（3/65） in samples from all swine farms.This study revealed that significant reduction in E.coli and coliform levels in sludge from covered lagoon biogas systems on swine farms.The presence of Salmonella as well as Cd and Pb,in significant amount in dry manure,suggests that there is a high probability of environmental contamination if it is used for agricultural purposes.Thus,careful waste and manure disposal from swine farms and the regular monitoring of wastewater is strongly recommended to ensure the safety of humans,other animals and the environment.

Quantification of multi-antibiotic resistant opportunistic pathogenic bacteria in bioaerosols in and around a pharmaceutical wastewater treatment plant

Pharmaceutical wastewater treatment plants（WWTPs） are thought to be a ＂seedbed＂ and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria（GNOPB） were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance（MAR） index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.

Recent progress on microfluidic biosensors for rapid detection of pathogenic bacteria

Rapid on-site detection of pathogenic bacteria with high sensitivity and specificity is becoming an urgent need in public health assurance, medical diagnostics, environmental monitoring, and food safety fields. Despite being reliable and widely used, the existing methods of bacteria detection are cumbersome and time-consuming, which is not conducive to field detection. Microfluidic lab-on-a-chip technology has provided a detective tool for various analytes, due to its miniaturization, portability and low reagent consumption. Within this progress report, advances in the bacteria detection using microfluidic biosensors were discussed. Typical methods for pathogenic bacteria capture, separation and detection were introduced respectively in the first part. Then key applications of microfluidic biosensor-based rapid bacteria detection were presented. Finally, we made a conclusion and discussed possible research prospects in aspects of microfluidic biosensors for rapid detection of pathogenic bacteria.

Metagenomic insights into the variation of bacterial communities and potential pathogenic bacteria in drinking water treatment and distribution systems

High-throughput sequencing of 16S rRNA gene amplicons was conducted to characterize the changing patterns of bacterial community and potential pathogens in full-scale drinking water treatment and distribution systems.Results showed that Actinobacteria was the predominant phylum in source water,while Proteobacteria dominated after chlorine disinfection and its relative abundance increased from 40.88%±9.45%to 67.86%±27.10%.The genera Pseudarthrobacter,Arenimonas,and Limnohabitans were effectively removed by chlorination,while Phreatobacter,Undibacterium,Pseudomonas,and Sphingomonas within the Proteobacteria phylum were greatly enriched after chlorination.Metagenomic analyses revealed the occurrence of 56 species of potential pathogenic bacteria within 17 genera in drinking water,mainly including Pseudomonas fluorescens and five mycobacteria species,which were also persistent in tap water samples.The bacteria were found to be involved in various pathways,among which considerable groups were related to human diseases,including infectious diseases and even cancers.

Recent advances in microchip-based methods for the detection of pathogenic bacteria

Pathogenic bacteria pose a global threat to public health and attract considerable attention in terms of food safety.Rapid and highly sensitive strategies for detecting pathogenic bacteria must be urgently developed to ensure food safety and public health.Microchips offer significant advantages for pathogenic bacterial detection in terms of speed and sensitivity compared with those of traditional techniques.Microfluidic devices,in particular,have attracted significant attention for the detection of pathogenic bacteria owing to their ease of operation,high throughput,cost-effectiveness,and high sensitivity.This review summarizes representative articles on the analysis of pathogenic bacteria using microchip-based systems.A detailed and comprehensive overview of microchip-based techniques for the detection of pathogenic bacteria is presented herein,and their advantages and disadvantages are discussed to compare their applications.The accomplishments and shortcomings of these microchips have been highlighted,and the direction of development and prospects of the analysis of pathogenic bacteria have been examined.The content of this review is anticipated to provide constructive suggestions for further development of highly effective and advanced microchip-based strategies for detecting pathogenic bacteria.