Air and hygiene quality in crowded housing environments – a case study of subdivided units in Hong Kong

The purpose of this study is to explore the environmental quality and hygiene in crowded living environments, subdivided units in Hong Kong. Subdivided units are an emerging form of housing environment for the urban poor. It is hypothesised that subdivided unit residents have a higher risk of exposure to poor hygiene conditions but no measurement has ever been taken to test this hypothesis. Twenty questionnaires and environmental assessments were conducted. Dominant bacterial species were identified as Micrococcus luteus and Staphylococcus spp., and the microbial counts were correlated with building, occupants and environmental parameters. Driven by the high bacterial counts and poor hygiene observation, eight subdivided units were selected for endotoxin, glucan and allergen analysis in bed and floor dust. Total airborne bacterial counts and endotoxin and glucan in dust were found at very high levels in some subdivided units, while unexpectedly, the allergen and mould levels were low. In crowded environments the skin bacteria may mislead the environmental and atmospheric bacterial contamination. Outdoor microbial pollution and deteriorated building conditions can be the main source of indoor contamination. ‘Good’ or ‘Excellent’ class of bacterial counts satisfying the Indoor Air Quality Objective does not guarantee a low endotoxin and glucan level.

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Identification of Pathogenic Microbes in Tools of Beauty Salon in Jeddah City

Biosciences Biotechnology Research Asia ◽

10.13005/bbra/2956 ◽

2021 ◽

Vol 18 (4) ◽

pp. 743-756

Author(s):

Najwa Alharbi ◽

Hanan Mohammed Alhashim

Keyword(s):

Fungal Infections ◽

Micrococcus Luteus ◽

Bacterial Species ◽

Major Health ◽

Beauty Salon ◽

Jeddah City ◽

Staphylococcus Equorum ◽

Pathogenic Microbes ◽

Staphylococcus Spp ◽

Major Health Issue

Beauty salons may draw in customers with glamour; however, they could also be considered a major health issue. They can cause the spread of bacterial and fungal infections. The purpose of this research was to identify pathogenic microbes from beauty salon tools. Microorganisms from contaminated salon tools and cosmetic products were isolated using various selective media. Microbial isolates were identified based on their molecular and biochemical characteristics. The most common bacterial species isolated were Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus equorum, Microbacterium spp., Bacillus siamensis, Bacillus subtilis, Sphingomonas aeria, Macrococcus spp., Microbacterium oxydans, Brachybacterium spp., Micrococcus luteus, and Brachybacterium nesterenkovii. Fungal isolates included Penicillium spp., Aspergillus niger, Purpureocillium lilacium, and Aspergillus flavus. Overall, Staphylococcus spp. and A. niger were the most common organisms isolated from the samples. The presence of potential pathogens indicates that the tools used in salons have not been adequately sterilized and the high risk of diseases spread.

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Utilization of induction furnace steel slag based iron oxide nanocomposites for antibacterial studies

SN Applied Sciences ◽

10.1007/s42452-021-04299-9 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

J. Baalamurugan ◽

V. Ganesh Kumar ◽

T. Stalin Dhas ◽

S. Taran ◽

S. Nalini ◽

...

Keyword(s):

Antibacterial Activity ◽

Iron Oxide ◽

Building Materials ◽

Induction Furnace ◽

Micrococcus Luteus ◽

Bacterial Species ◽

Steel Slag ◽

If Steel ◽

Growth Inhibitory ◽

Microplate Reader

AbstractMetals and metal oxide-based nanocomposites play a significant role over the control of microbes. In this study, antibacterial activity of iron oxide (Fe2O3) nanocomposites based on induction furnace (IF) steel slag has been carried out. IF steel slag is an industrial by-product generated from secondary steel manufacturing process and has various metal oxides which includes Al2O3 (7.89%), MnO (5.06), CaO (1.49%) and specifically Fe2O3 (14.30%) in higher content along with metalloid SiO2 (66.42). Antibacterial activity of iron oxide nanocomposites has been revealed on bacterial species such as Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus. Micrococcus luteus has undergone maximum zone of inhibition (ZOI) of 12 mm for 10 mg/mL concentration of steel slag iron oxide nanocomposite. Growth inhibitory kinetics of bacterial species has been studied using ELISA microplate reader at 660 nm by varying the concentration of steel slag iron oxide nanocomposites. The results illustrate that IF steel slag is a potential material and can be utilized in building materials to increase the resistance against biodeterioration. Graphic abstract

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Evaluation of Commercial Disinfectants against Staphylococcus lentus and Micrococcus spp. of Poultry Origin

Veterinary Medicine International ◽

10.1155/2020/8811540 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Otun Saha ◽

Nadira Naznin Rakhi ◽

Arif Istiaq ◽

Israt Islam ◽

Munawar Sultana ◽

...

Keyword(s):

Micrococcus Luteus ◽

Bacterial Species ◽

16S Rrna Gene Sequencing ◽

Average Diameter ◽

Diffusion Method ◽

Dilution Method ◽

Rrna Gene ◽

Poultry Farms ◽

Rrna Gene Sequencing ◽

Selection Of

Introduction. Effective sanitation strategies for poultry farms require an appropriate selection of the disinfectant based on the contaminants present and their sensitivity to the disinfectants. Aim. The current study investigated the prevalence of streptococci/micrococci in poultry farms of Bangladesh and the efficacy of commercial disinfectants (Savlon, Lysol, Quatovet, Virkon S, and Virocid) along with alcohol against these pathogens to adopt appropriate strategies. Materials and Methods. Conventional approaches and the 16S rRNA gene sequencing were performed to confirm the isolates at the species level along with microtiter biofilm assay to determine their biofilm-forming ability. Efficacy of the disinfectants was tested against those isolates using agar well diffusion and minimum inhibitory concentration (MIC) test by broth dilution method using different dilutions of the disinfectants. Results. Staphylococcus lentus (n = 32), Micrococcus luteus (n = 7), and Micrococcus aloeverae (n = 4) were confirmed among 102 presumptively screened streptococci/micrococci isolates from 43 samples. No single disinfectant showed equally high efficacy against all three bacterial species in agar well diffusion test, although Virocid showed the lowest MIC against all three of them. Lysol was least effective among the commercial disinfectants by both MIC and diffusion method, although each commercial disinfectant was more effective than alcohol. Considering both the average diameter of the inhibition zones and the MIC values, efficacy can be interpreted as Virocid > Quatovet > Savlon > Virkon S > Lysol. Although the efficacy decreased with decreasing concentration, the disinfectants retained a satisfactory level of efficacy at 50% concentration. Among test pathogens, M. aloeverae was the most sensitive to the disinfectants and the weakest biofilm producers, whereas 4/14 S. lentus and 1/5 M. luteus were strong biofilm producers, which may cause more reduction in the efficacy in environmental conditions. Conclusion. As no ideal disinfectant was found in the study, the efficacy of the disinfectants should be routinely evaluated and validated to ensure the sanitation standards in the poultry sector.

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Multiparameter Flow Cytometric Analysis of Antibiotic Effects on Membrane Potential, Membrane Permeability, and Bacterial Counts of Staphylococcus aureus andMicrococcus luteus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.4.827-834.2000 ◽

2000 ◽

Vol 44 (4) ◽

pp. 827-834 ◽

Cited By ~ 159

Author(s):

David J. Novo ◽

Nancy G. Perlmutter ◽

Richard H. Hunt ◽

Howard M. Shapiro

Keyword(s):

Staphylococcus Aureus ◽

Flow Cytometry ◽

Membrane Potential ◽

Membrane Permeability ◽

Micrococcus Luteus ◽

Flow Cytometric Analysis ◽

Bacterial Counts ◽

Flow Cytometric ◽

Permeability Parameter ◽

Particle Counts

ABSTRACT Although flow cytometry has been used to study antibiotic effects on bacterial membrane potential (MP) and membrane permeability, flow cytometric results are not always well correlated to changes in bacterial counts. Using new, precise techniques, we simultaneously measured MP, membrane permeability, and particle counts of antibiotic-treated and untreated Staphylococcus aureus andMicrococcus luteus cells. MP was calculated from the ratio of red and green fluorescence of diethyloxacarbocyanine [DiOC2(3)]. A normalized permeability parameter was calculated from the ratio of far red fluorescence of the nucleic acid dye TO-PRO-3 and green DiOC2(3) fluorescence. Bacterial counts were calculated by the addition of polystyrene beads to the sample at a known concentration. Amoxicillin increased permeability within 45 min. At concentrations of <1 μg/ml, some organisms showed increased permeability but normal MP; this population disappeared after 4 h, while bacterial counts increased. At amoxicillin concentrations above 1 μg/ml, MP decreased irreversibly and the particle counts did not increase. Tetracycline and erythromycin caused smaller, dose- and time-dependent decreases in MP. Tetracycline concentrations of <1 μg/ml did not change permeability, while a tetracycline concentration of 4 μg/ml permeabilized 50% of the bacteria; 4 μg of erythromycin per ml permeabilized 20% of the bacteria. Streptomycin decreased MP substantially, with no effect on permeability; chloramphenicol did not change either permeability or MP. Erythromycin pretreatment of bacteria prevented streptomycin and amoxicillin effects. Flow cytometry provides a sensitive means of monitoring the dynamic cellular events that occur in bacteria exposed to antibacterial agents; however, it is probably simplistic to expect that changes in a single cellular parameter will suffice to determine the sensitivities of all species to all drugs.

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Isolation and characterization of bacteria residing in the oral, gut, and fecal samples of different pheasant species

Brazilian Journal of Biology ◽

10.1590/1519-6984.249159 ◽

2023 ◽

Vol 83 ◽

Author(s):

M. Mushtaq ◽

S. M. Bukhari ◽

S. Ahmad ◽

A. Khattak ◽

M. B. Chattha ◽

...

Keyword(s):

Bacterial Species ◽

Gut Contents ◽

Phasianus Colchicus ◽

Gut Content ◽

E Coli ◽

Colony Forming Unit ◽

Isolation And Characterization ◽

Staphylococcus Spp ◽

Campylobacter Spp

Abstract There is a paucity of research conducted on microbial prevalence in pheasants. The microbiota of captive birds has zoonotic significance and must be characterize. Present study is therefore planned to assess the microbiota from oral, fecal and gut content of captive avian species. It will be helpful in characterization of harmful microbes. Different samples taken from oral, gut and feces of ring-necked pheasants (Phasianus colchicus), green pheasants (Phasianus versicolor), golden pheasant (Chrysolophus pictus) and silver pheasant (Lophura nycthemera). Samples were collected, diluted, and inoculated onto different agar plates (MacConkey, SS agar, MSA and nutrient agar) for cultivation of bacterial species. Colonies of E.coli, Staphylococcus spp. Brachyspira spp. and Campylobacter spp were observed based on colony morphology. Colony forming unit showed E. coli as frequently found bacteria in fecal, oral and gut contents of all the above pheasants. The overall significance difference was found among bacterial species of golden pheasants, green pheasant, ring-necked pheasant, and silver pheasants. It was concluded that E.coli is predominant isolated from heathy pheasants followed by Campylobacter, Staphylococcus and Brachyspira.

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Metabolism of azo dyes by human skin microbiota

Journal of Medical Microbiology ◽

10.1099/jmm.0.012617-0 ◽

2010 ◽

Vol 59 (1) ◽

pp. 108-114 ◽

Cited By ~ 55

Author(s):

Robin L. Stingley ◽

Wen Zou ◽

Thomas M. Heinze ◽

Huizhong Chen ◽

Carl E. Cerniglia

Keyword(s):

Human Skin ◽

Bacterial Species ◽

Assessment Process ◽

Ionization Mass ◽

Stationary Growth ◽

Staph Aureus ◽

Proteomic Data ◽

Skin Bacteria ◽

Staphylococcus Capitis ◽

Ponceau S

Reduction of Methyl Red (MR) and Orange II (Or II) by 26 human skin bacterial species was monitored by a rapid spectrophotometric assay. The analysis indicated that skin bacteria, representing the genera Staphylococcus, Corynebacterium, Micrococcus, Dermacoccus and Kocuria, were able to reduce MR by 74–100 % in 24 h, with only three species unable to reduce completely the dye in that time. Among the species tested, only Corynebacterium xerosis was unable to reduce Or II to any degree by 24 h, and only Staphylococcus delphini, Staphylococcus sciuri subsp. sciuri and Pseudomonas aeruginosa were able to reduce completely this dye within 24 h. MR reduction started with early-exponential growth in Staphylococcus aureus and Staphylococcus epidermidis, and around late-exponential/early-stationary growth in P. aeruginosa. Reduction of Or II, Ponceau S and Ponceau BS started during late-exponential/early-stationary growth for all three species. Using liquid chromatography/electrospray ionization mass spectrometry analyses, MR metabolites produced by Staph. aureus, Staph. epidermidis and P. aeruginosa were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Searches of available genomic and proteomic data revealed that at least four of the staphylococci in this study, Staphylococcus haemolyticus, Staph. epidermidis, Staphylococcus cohnii and Staphylococcus saprophyticus, have hypothetical genes with 77, 76, 75 and 74 % sequence identity to azo1 encoding an azoreductase from Staph. aureus and hypothetical proteins with 82, 80, 72 and 74 % identity to Azo1, respectively. In addition, Staphylococcus capitis has a protein with 79 % identity to Azo1. Western analysis detected proteins similar to Azo1 in all the staphylococci tested, except Staph. delphini, Staph. sciuri subsp. sciuri and Staphylococcus auricularis. The data presented in this report will be useful in the risk assessment process for evaluation of public exposure to products containing these dyes.

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COMPARATIVE ANALYSIS OF METAL NANOPARTICLES SYNTHESIZED FROM HIBISCUS ROSA SINESIS AND THEIR ANTIBACTERIAL ACTIVITY ESTIMATION AGAINST NINE PATHOGENIC BACTERIA

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2017.v10i5.17458 ◽

2017 ◽

Vol 10 (5) ◽

pp. 323

Author(s):

Shruti Tyagi

Keyword(s):

Antibacterial Activity ◽

Pathogenic Bacteria ◽

Au Nanoparticles ◽

Size Range ◽

Micrococcus Luteus ◽

Bacterial Species ◽

Cost Effective ◽

Antibacterial Activities ◽

Agar Disc ◽

Vis Spectroscopy

Objective: This study demonstates a simple, cost effective protocol for biosynthesis of stable silver (Ag) and gold (Au) nanoparticles from Hibiscus Rosa sinesis and their comparison by applying antibacterial activities against nine pathogenic bacterial species.Methods: Silver (Ag) and gold (Au) nanoparticles were biosynthesized from Hibiscus Rosa sinesis were characterized by UV–VIS spectroscopy, FTIR and TEM. The antibacterial activities of AgNPs and AuNPs were evaluated against 9 pathogenic bacterial species Pseudomonas aeroginosa, Bacillus subtilis Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogens, Escherichia coli, Streptococcus pneumoniae, Aeromonas hydrophila by the agar disc diffusion method.Results: Synthesized AgNPs were obtained in 13.01 to 28.14 nm size range, while AuNPs were in 6.32 to 18.19 nm size range. The results of Fourier transform infrared spectroscopy (FTIR) spectra indicates that the AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups. The antibacterial activities of AgNPs, the zone of inhibition significantly increased with the increases of concentrations of AgNPs in all pathogenic bacterial species except in the case of S. epidermidis at 50%, S. aerogenes and A. hydrophila at 70%, while in case of AuNPs antibacterial activity was displayed only against B. subtilis at 20% and 100% concentration.Conclusion: This study suggests that AgNPs exhibits outstanding antibacterial activity against pathogenic bacteria as compared to AuNPs synthesized from Hibiscus Rosa sinensis leaf extract and insights to their potential applicability as an alternative antibacterial agent in microbial and human health system to reduce the resistance ability of pathogenic bacteria. Keywords: silver nanoparticles; gold nanoparticles; UV–VIS spectroscopy; FTIR; TEM; antibacterial activities.

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Failure of hand disinfection with frequent hand washing: a need for prolonged field studies

Journal of Hygiene ◽

10.1017/s0022172400052906 ◽

1977 ◽

Vol 79 (1) ◽

pp. 107-119 ◽

Cited By ~ 65

Author(s):

Juhani Ojajärvi ◽

Paavo Mäkelä ◽

Ilari Rantasalo

Keyword(s):

Field Studies ◽

Hand Washing ◽

Bacterial Colony ◽

Bacterial Counts ◽

Disinfection Methods ◽

Skin Bacteria ◽

Before And After ◽

Short Time ◽

Hospital Wards

SUMMARYIn a prolonged field trial a 4% chlorhexidine digluconate detergent scrub (HibiscrubR), that had earlier proved to be an effective hand disinfectant, was studied in hospital wards. Finger tips were found to harbour more bacteria than the hand dorsum and the samples collected from them yielded more information on the bacteriological and dermatological effects of hand disinfectants in practice.In wards with a relatively low hand-washing frequency (less than 20 times in 8 hours) the bacteriological results resembled those obtained by in-use tests with volunteers. In the neonatal unit where the hand washing frequency was remarkably high, even occasionally over 100 times/8 h shift, an increase in the bacterial colony counts of the majority of the staff was recorded both before and after hand washing already after using the preparation for 1 week. Age, occupation and hand-washing frequency all correlated with the bacteriological results. Twenty-seven out of 37 persons complained of side effects such as wounds of finger tips and redness or heavy drying of the skin. Wounds, particularly on finger tips, resulted in the failure of disinfection. An increase in bacterial counts was sometimes noted without any dermatological or subjective changes. Drying of the skin was complained of less often when no increase in skin bacteria occurred.After the changeover of washing practice to a detergent followed by a rinse with spirit solution containing chlorhexidine and glycerol a decrease was recorded in the bacterial counts. It is concluded that more attention should be paid to long-term testing of hand washing and disinfection methods to ensure optimum final results in practice. It is obvious that the knowledge obtained from short time in-use testing cannot be applied to all conditions of use.

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Bacteriological examination of a modern animal house containing small laboratory animals

Laboratory Animals ◽

10.1258/002367779781071311 ◽

1979 ◽

Vol 13 (1) ◽

pp. 21-27 ◽

Cited By ~ 1

Author(s):

Martin Wierup

Keyword(s):

Staphylococcus Epidermidis ◽

Bacterial Species ◽

Laboratory Animals ◽

Bacteriological Examination ◽

Small Laboratory ◽

Bacterial Counts ◽

Colony Forming Units ◽

Animal House ◽

Conventional Unit ◽

Bacteriological Contamination

Floors and other areas totalling 1800 m2, comprising conventional and specified-pathogen-free (SPF) units, were screened bacteriologically 6 times in a year. The contamination indices observed were lower within than outside the units, and lower in the SPF than in the conventional unit. Bacterial counts in rooms containing animals in the conventional and SPF units were very similar. In all of the areas investigated within the units, most of the samples revealed <2 colony forming units per cm2. In contrast, high degrees of bacteriological contamination were detected in the changing rooms after showering or washing before entry. Staphylococcus epidermidis was the dominant bacterial species isolated. The bacteriological spectrum did not vary between the areas surveyed.

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Biosorption and Characterization of Metal Tolerant Bacteria Isolated from Palar River Basin Vellore

Journal of Scientific Research ◽

10.3329/jsr.v6i1.14678 ◽

2013 ◽

Vol 6 (1) ◽

pp. 125-131 ◽

Cited By ~ 1

Author(s):

S. Silambarasan ◽

J. Abraham

Keyword(s):

Heavy Metals ◽

Antibiotic Resistance ◽

River Basin ◽

Metal Tolerance ◽

Micrococcus Luteus ◽

Bacterial Species ◽

Heavy Metal Tolerance ◽

Enterobacter Aerogenes ◽

Alcaligenes Faecalis ◽

Antibiotics Resistance

Metal pollution is a growing problem and microbes have adapted to tolerate the presence of metals and even use them. The investigation was carried out to screen for bisorption property of metals by bacteria and check for correlation between tolerance to heavy metals and antibiotic resistance. Soil samples were collected from Palar River basin site of Vellore and five distinct bacteria were isolated. Antibiotic resistance (bacitracin, chloramphenicol, streptomycin, rifampicin, penicillin and ampicillin) was checked and tolerance to heavy metals was screened (Cd, Pb, Cu and Zn). It was found that most of the bacterial isolates had multiple antibiotic resistances which might be due to the stress caused by heavy metals released into the Palar river basin, Vellore. The multiple antibiotics resistance of this bacterial species was found to be associated with tolerance to metals. Biosorption studies revealed that Alcaligenes faecalis could tolerate 59% Cd, 61% Pb, 40% Cu, 39% Zn and Staphylococcus aureus removed 60% Cd, 63% Pb, 42% Cu, 41% Zn and Streptococcus lactis absorbed 61% Cd, 57% Pb, 37% Cu, 38% Zn and Micrococcus luteus reduced 56% Cd, 61% Pb, 39% Cu, 41% Zn and Enterobacter aerogenes removed 60% Cd, 55% Pb, 62% Cu, 67% Zn. Keywords: Antibiotic resistant; Heavy metal tolerance; Biosorption; Metal polluted soils. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i1.14678 J. Sci. Res. 6 (1), 125-131 (2014)

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