Microbial contamination of multiple-dose preservative-free hospital ophthalmic preparations in a tertiary care hospital

Background:It is possible that preservative-free eye drops can be contaminated.The aim of this study was to assess the incidence of microbial contamination of preservative-free hospital-prepared anti-infective eye drops and investigate factors that contribute to contamination.This finding may help to raise awareness of this problem to medical healthcare staff and patients in order to prevent the transmission of microorganisms from eye drops to the patients through treatment of pre-existing eye diseases.Methods:Two hundred and ninety-five eye drop bottles were collected from patients attending Rajavithi Hospital Ophthalmologic outpatient and inpatient department,including both those used by patients at home and those administered in the hospital by medical staff.Samples were taken from the tips of droppers and bottles,and the residual fluid inside the bottles was then cultivated onto different culture plates.The culture results were identified and analyzed according to various factors related to both individual users and the bottles.Results:Seven different types of eye drops were collected and 71(24.06%)of the 295 bottles were contaminated.Vancomycin eye drops were the most contaminated.Twenty-six different types of pathogens were identified,most frequently mold(42.98%),and the amount of contamination was higher in tips than in residual fluid inside the bottle.There was no statistically significant difference in contamination between patients used eye drops collected in outpatient units(32.14%)and medical staff used eye drops collected in inpatient settings(23.22%).The only factor that was statistically significant was the number of eye drops used per person.We found that samples from patients who used only up to 2 eye drops suffered contamination(42.8%)more than those from their counterparts who used at least 3(22.18%),P¼0.02.Conclusions:Of these preservative-free hospital preparations anti-infective eye drops,24.06%were contaminated.The number of eye drops used per person was statistically significant in triggering contamination.There is a possibility of number of eyedrops use person may trigger contamination.

Surveillance and examination of microbial contamination in ice cream in China

This study investigated the microbial contamination of ice cream in China.A total of 2887 ice cream samples were collected from different regions of China.Contamination by the aerobic plate count(APC),coliforms,and three foodborne pathogens,Listeria monocytogenes(L.monocytogenes),Staphylococcus aureus(S.aureus),and Salmonella spp.,was detected in the samples.L.monocytogenes isolates were further analyzed for antibiotic susceptibility and multi-locus sequence typing(MLST).The results showed that APC was more than 10^(5) colony forming units(CFU)/g in 6.10%(176/2887)and coliform was more than 10^(2) CFU/g in 15.69%(453/2887)of all samples.The positive rates of S.aureus,L.monocytogenes,and Salmonella spp.were 0.66%,0.62%,and 0.10%,respectively.Among these,S.aureus contamination was more than 102 CFU/g in two samples,and L.monocytogenes in the positive sample was in the range of 0.3-240 most probable number(MPN)/g.with a median of 4.3 MPN/g.The hygienic status of the packaged samples was much better than that of the bulk samples(P<0.05).Catering samples were more frequently and heavily contaminated than samples from retail and wholesale outlets(P<0.05).No significant differences were observed in samples bought from urban and rural areas(P>0.05).For 18 L.monocytogenes strains isolated from ice cream,the resistance rate of nine antibiotics was 5.56%(1/18).By MLST,the L.monocytogenes strains were classified into nine sequence types(STs),of which ST8 was the most common(six isolates).These results indicate that a potential health risk to the public may be caused by ice cream,particularly in susceptiblepopulations.

Comparative analysis of bacterial contamination in tap and groundwater: A case study on water quality of Quetta City, an arid zone in Pakistan

Water is an essential element on earth,which provides human a variety of services in domestic use,agriculture,or industries.However,some serious health risks of drinking water are associated with microbial contamination,particularly with fecal matter.Therefore,microbial quality assessment is considered to be a necessary component of water quality assessment.This study investigates microbial contamination of water distributary system around the city by comparing groundwater(GW)and tap water(TW)quality in Quetta city.31 GW samples and 31 TW samples were collected in the study area during the months of September,October,and November.Fecal coliform test was carried out in laboratory and their average total coliform contamination was computed.Results showed that the TW sample were all contaminated by coliform except for Chiltan town,hence are not considered suitable for drinking without any treatment according to WHO drinking water quality standards.The average coliform concentrations were 12 in Quetta main city,11.6 in Jinnah town,5.3 in Satallite town,10 in Shahbaz town and 5 in Brewery town(0/100 mL CFU)and the TW samples from the three towns were even more contaminated with E.coli.Whereas among the GW,average microbial concentrations were 1.8 in Quetta main city,2 in Satallite town,1.4 in Shahbaz town,and 0.4 in Chiltan town(0/100 mL CFU),respectively,which shows that the contamination is occurring within the water distributary pipeline system when the water flows through the pipelines.Moreover,this research will be valuable for researchers and administrative authorities to conduct elaborative studies,and develop new policies to prevent further deterioration of drinking water in the water distribution system by pathogenic microorganisms and ensure safe drinking water to the public of Quetta city.

Microbial Assessment and Antibiotic Susceptibility Profile of Bacterial Fish Isolates in an Aquaculture Production Site in Mefou Afamba Division of Cameroon

The practice of integrated fish farming and the use of local fish meal and manure for fish feeding in Cameroon constitute potential sources of resistant pathogenic bacteria in the fish pond environment.Therefore,a periodical and constant monitoring of the microbiological quality of fish pond is imperative.This study was to assess the microbial contamination of Mfou aquaculture production site and evaluate the antibiotic resistance profile of bacterial fish isolates.Samples of pond water(n=36),sediment(n=36),fishmeal(n=12)and African catfish(Clarias gariepinus),kanga(Heterotis niloticus)and Nile Tilapia(Oreochromis niloticus)(n=36,each)were collected to determine TVAC(Total Viable Aerobic Bacterial Count),FC(Fungal Count),SAC(Staphylococcus aureus count),TCC(Total Coliform Count)and FCC(Feacal Coliform Count).The fish skin isolates of S.aureus,Enterobacter sakazakii,Citrobacter freundii,Serratia fonticola,Klebsiella oxytoca,Proteus spp.,Aeromonas hydrophila,Kluyvera spp.,Moraxella spp.,Pasteurella multocida and Pseudomonas fluorescens were tested against penicillin G(10μg),chloramphenicol(30μg),sulfamethoxazole/trimethoprim(25μg),erythromycin(15μg),tetracycline(30μg),using the disk diffusion method.Results reveal a heavy contamination of fish farms with microbial load above the recommended limits.Our study indicates that fish ponds are sources of zoonotic pathogens underlining their epidemiological and clinical relevance.All bacterial isolates were multiresistant with a multiple antibiotic resistance index above 0.2.These data raise concern about the microbial contamination of aquaculture and associated public health risks in Cameroon.

Microbial Monitoring and Mitigaiton in Cementing Operations

Microbial contamination and bacteria growth in the cementing makup water impact cementing operation and integrity.To avoid the premature cement setting caused by microbial growth,the water is usually treated with biocides for microbial control before mixing.This treatment will also prevent biodegradation of the added polymers and stabilize the slurry rheological properties.Make-up water and cementing mix samples were collected from active drilling rigs in the field.In 12 hours biocide addition program,the tested biocide at 50,100,250,and 500 ppm for cementing operations revealed acceptable control of both GAB and SRB numbers in one Field,but not in another Field.In 24 hours biocide addition program,revealed varying levels for control microbial contamination in cementing operations,with higher efficiency with Field B samples opposed to field A,and with better control at higher concentrations of tested biocide at 250,and 500 ppm.As a recommendation therefore,usage of another biocide with a different chemistry at Field A is encouraged once a new biocide is selected.

Fungal contaminations of indoor and outdoor air of buildings of the University of Cape Coast,Ghana

The presence of microscopic spores in the air affects the quality of air inhaled by animals including humans.Microbial contamination of air impacts the well-being of occupants of an indoor environment,sometimes with dire consequences.The study investigated fungal contaminations of indoor and outdoor air of the Hospital,Library and Senior Common Room(SCR)of the University of Cape Coast,Ghana.Indoor and outdoor air was sampled using the Koch’s sedimentation method.Colony forming units per cubic meter of air(cfu/m^(3))were determined with the Omeliansky formula.The isolated fungi were identified based on morphological and growth characteristics.For indoor air,the least colony counts were recorded in the SCR for both morning and afternoon samples,whilst the Hospital air had the highest colony counts.For outdoor air,the colony counts were lower in SCR and the Library for both morning and afternoon samples compared to the Hospital.The results further indicated that indoor concentrations of fungi,for morning and afternoon,ranged between 4.0x10^(4) and 2.1x10^(5) cfu/m^(3),whereas outdoor concentrations of fungi ranged between 1.1x105 and 3.0x10^(5) cfu/m^(3),revealing an overall higher levels of contamination of outdoor air than indoor air at all the three buildings.Consequently,estimated indoor/outdoor(I/O)concentration ratios of fungi revealed an exogenous source of indoor contaminations at all the three buildings sampled.Fungi isolated from indoor and outdoor air were of the genera Aspergillus,Curvularia,Cylindrocarpon,Fusarium,Mucor,Neurospora,Penicillium and Rhodotorula.We conclude that indoor and outdoor air of the buildings sampled were contaminated with airborne fungi;however,based on estimated I/O ratios,the indoor ambient conditions of the buildings were good.The implication of findings of this study is that the presence of airborne fungal contaminants of indoor and outdoor workplace environment may pose serious occupational health consequences,hence low productivity.

Assessment of Drinking Water Quality Served in Different Restaurants at Islam Nagor Road Adjacent to Khulna University Campus, Bangladesh

Potable water is a growing requirement for sound health as contaminated water and water-borne pathogens pose serious health risks to human beings. Considering this issue, the current study aimed to assess the drinking water quality served in different restaurants close to the Khulna University campus in Bangladesh. A total number of ten drinking water samples were collected from different restaurants. Afterward, the collected water samples were analyzed to examine the physico-chemical properties and microbiological contamination of the water samples. Besides, microbial properties such as Total Coliform (TC), Fecal Coliform (FC), and E. coli were analyzed by the Membrane Filtration (MF) technique. The findings suggest that all the physico-chemical attributes were within the permissible limits regarding recommended Bangladesh standards and WHO guidelines. But in case of EC, 40% of the samples exceeded the WHO permissible limits and for sodium, 10% of samples exceeded both the BD and WHO standards. In addition, the results disclosed that the drinking water served in different restaurants was contaminated by TC, FC, and E. coli. It is observed that 100% of the samples were contaminated by TC and FC whereas 70% of the samples were contaminated by E. coli. Consequently, it is clearly evident that the water is considered suitable with respect to physico-chemical analysis but this drinking water is unfit for consumption while taking into account its microbiological quality. The total coliform, fecal coliform, and E. coli count attests to the fact that anyone can become harmed at any moment by ingesting water from roadside restaurants. Finally, due to bacterial contamination, the served drinking water in these places doesn’t meet safe and suitable water excellence, therefore, consumption of this water is deleterious to public health.

Advances in strategies to assure the microbial safety of food-associated ice

Ice has been extensively employed as a general coolant or ingredient in the food industry.However,evident indicates that food-associated ice can be easily contaminated by pathogenic bacteria,such as Escherichia coli,Staphylococcus aureus,and Salmonella spp.,among others.The contamination sources are attributed to the use of unhygienic water,improper handling,and poor hygiene conditions of ice-making machines.The contaminated ice might be a vesicle for the transmission of pathogens to food and human,posing potential risks to public health.This review overviewed the microbial contamination of food-associated ice,including the microbial contamination levels and the main microbial contaminants.In addition,a systematical introduction was constructed on the recent advances and applications of state-of-the-art methods to manufacture safe ices,illustrating ozone,electrolyzed water,cold plasma,essential oils,and ultraviolet light-emitting diode irradiation.The validities and limitations of ice treated by these techniques on the food quality were then discussed in detail.Various studies were also organized to demonstrate the potential of the mentioned treated ice,for ensuring the microbial safety and control quality deterioration during the storage of aquatic products.Finally,the direction for future study was given.

Effects of Peeling with Flexible Alloy Blade on Naked Oats

This research reported the effect of peeling naked oats with a peeling machine equipped with the flexible alloy blade.Results showed that the flexible alloy blade could achieve the same effect as traditional abrasive rolls. Furthermore, the new peeling method had hardly damage to the oat kernels. The result of scanning electron microscopy indicated the surface of peeled naked oats by the flexible alloy blade is homogeneous. The gap between the flexible alloy blade and the slotted screen could change the particle sizes of the flours obtained, which differed from traditional peeling machines. In addition, peeling for 15 seconds significantly reduced the microbial contaminants. The removal of outer layer decreased the lipase activity. The technological parameters were optimized by orthogonal L_9(3~4) test, the results showed a 30 s peeling time and 2% second-addition of water contributed to the peeling rate. The texture analysis demonstrate that the hardness of cooked groats decreases obviously after peeling treatments.

Effect of dates on blood glucose and lipid profile among patients with type 2 diabetes

Poor fruit and vegetable consumption is one of the 10 major risk factors for mortality.There is a misconception regarding the consumption of dates among patients with diabetes.This manuscript assessed the effects of date consumption on fasting and postprandial blood glucose,glycated hemoglobin,total cholesterol,triglycerides,low-density lipoproteins,high-density lipoproteins,and microbial markers.Four literature databases were searched for relevant articles.Of the 595 studies retrieved,24 assessed the effects of dates on glycemic control and lipids.Overall,the evidence suggests that dates have a lowering effect on blood glucose.Dates reduce total cholesterol and triglyceride levels and increase high-density lipoprotein levels.Dates also promote the abundance of beneficial gut microbiota.Therefore,patients with diabetes and dyslipidemia can consume dates to reduce their blood glucose,cholesterol,and triglycerides.

Development of a monitoring system for Huangjiu storage based on electrical conductivity

In order to quickly detect the rancidification of Huangjiu in pottery jars,this study developed a fast detection method based on the principle of electrical conductivity changes caused by microbial contamination.The change in total acid in Huangjiu was positively correlated with the increase of electrical conductivity.This method was applied to an online monitoring system for Huangjiu storage in stainless steel tanks.When the electrical conductivity exceeds the normal fluctuation range(mean+3 standard deviations)of previous data,the monitoring system recognizes microbial contamination.By optimizing the conductivity-temperature compensation coefficient and conductivity statistical method,the standard deviation of the method was reduced and the sensitivity of microbial pollution monitoring was improved.The ranges of conductivity and compensation coefficient of common types of Huangjiu were estimated.Interference in conductivity measurements due to environmental factors was minimised through the synchronous comparison of conductivity data for multiple tanks of Huangjiu.The standard deviation,which indicates the fluctuation range of the system,decreased from 143 to 2μS/cm.The monitoring system was then applied in Huangjiu storage tanks with capacities of 60 t and 300 t.Through the comparison of conductivity data change,the abnormal signals caused by microbial contamination during the storage of Huangjiu were found over time.Meanwhile,through offline detection of total acid in Huangjiu,the effectiveness of microbial contamination online detection was verified.

New strategy to delay food spoilage:Application of new food contact material with antibacterial function

Frequent food poisoning and food-borne diseases outbreaking in recent years have caused people to attach great attention to food safety,especially the food contact materials that are essential in the food industrial chains and daily lives,ensuring their clean sanitation are of great importance in blocking microbial contamination and spread of food-borne pathogens.Stainless steel(SS)is one of the most accepted and widely used food contact material,and the Cu-bearing SS possesses excellent antibacterial performance and maintains the original mechanical properties of SS,maybe making it a better substitute for the conventional SS in the food area.Taking advantages of bactericidal and antifouling properties of Cubearing SS,this study simulated a variety of food contact scenarios,explored a new strategy for food preservation and food safety by using Cu-bearing SS as a food contact material.The results showed that the Cu-bearing SS could not only delay the spoilage of different foods by inhibiting the activity of microorganisms in foods,but also reduce the expressions of spoilage traits of bacteria as well as the formation of biofilms by quenching the quorum-sensing signals,and further creating a good bacteriostatic atmosphere for the contacted food and its surrounding environment.In addition,the remarkable antifouling property of Cu-bearing SS would give the material a self-cleaning feature for food applications,which can avoid secondary contamination of food as a source of contamination.This study well demonstrates that the Cu-bearing SS has broad application potentials and prospects in the food area.

Rapid and accurate evaluation of vaporized hydrogen peroxide on the efficiency of disinfection, using a sensitive dual-channel laser scanning cytometer

Vaporized hydrogen peroxide(VHP)is a highly active disinfectant,and VHP decontamination systems have been widely applied in hospitals,microbiological laboratories,and pharmaceutical industries.However,the decomposition of VHP into non-toxic by-products is essential.Evaluation of the disinfection efficacy of VHP is crucial to ensuring the reliability of VHP disinfection and controlling microbial contamination.In this study,a rapid and sensitive strategy is proposed to evaluate the efficacy of VHP in surface disinfection by detecting the survived and killed bacteria from VHP-exposed biological indicators(BIs).A dual-channel solid-phase cytometer is designed,and fluorescent dyes are used as indicators to automatically and accurately distinguish live cells from dead cells in themixtures of bacteria.To verify the availability and effectiveness of the laser scanning cytometry,experiments on its application in estimating the efficacy of VHP disinfection practice have been carried out in this study,and its estimation effect compared with that of the traditional plate counting method.Results show that the proposed assay might distinctly identify live or killed cells labeled by green and red fluorescent dyes and examined the disinfection efficacy in 30 min by calculating the bactericidal rate.Compared with the plate counting method,the proposed approach is accurate and practical,with an average detection efficiency of 98.47%±1.55%.Moreover,an excellent correlation between the concentrations of B.subtilis var niger(ATCC 9372)measured by the proposed detection system and by the plate counting method is noticed(R2=0.9971),indicating that this approach had advantages in the detection of trace microorganisms.To summarize,the proposed strategy appears practical and significant in many fields in which microbial counting and identification are required.

Investigation of potential strategies to control malt-induced premature yeast flocculation

Premature yeast flocculation(PYF)during beer fermentation is an undesired event by which yeast flocculate too early and heavily before the wort nutrition is exhausted.While PYF can be a major financial detriment to brewers,the conditions that trigger it and the chemical composition of PYF are poorly understood.Gas chromatography-mass spectrometry results from this study indicated that purified malt PYF factor consisted of numerous polysaccharides;however,no protein was identi-fied.High concentrations of PYF promoted further yeast flocculation,which in turn decreased the rate of fermentation and increased acetaldehyde content of the beer.PYF factors were found to be derived primarily from malt husks and factors such as microbial content of the water used for germination,mixing malts with different PYF values,and presence of tannic acid were all found to influence the rate of yeast flocculation.Findings from this study may be beneficial in developing PYF prevention and control measures that can be applied to future brewing strategies.