Bacteriology - Science topic

We are a Chinese education company dedicated to helping our clients publish SCI, SCIE, SSCI WoS indexes quickly. We have a wide range of paper orders in various fields and we are actively looking for partners who can help us with our publishing work.

Please note that your service fee will be paid after acceptance and it is necessary for you to share your login information with me.

This precaution is taken to avoid any potential fraudulent activity, as unfortunately there are many dishonest people in the market and I am reluctant to work with them.

If you meet the above requirements, please feel free to contact me

Please read the paper first. Or at least the abstract.

Bacteriological activity in deep sandy groundwater can be influenced by a variety of factors, including the presence of nitrate and oxygen levels. In environments where oxygen is limited, such as deep sandy groundwater, bacteria may utilize alternative electron acceptors for respiration, such as nitrate.

The relationship between bacteriological activity and nitrate levels in deep sandy groundwater is complex and can be influenced by various environmental conditions. While some bacteria can use nitrate as an electron acceptor for respiration (a process known as denitrification), high levels of nitrate can also have negative impacts on microbial communities. Excessive nitrate concentrations may lead to changes in the microbial community structure and function, impacting overall bacteriological activity.

It's worth noting that specific bacterial species capable of denitrification will play a key role in determining the extent to which bacteriological activity is proportional to nitrate levels. Additionally, other factors such as pH, temperature, organic carbon availability, and the presence of other contaminants can also influence microbial activity in groundwater.

To fully understand the relationship between bacteriological activity and nitrate levels in deep sandy groundwater with limited oxygen, detailed scientific studies would need to be conducted under specific local conditions. These studies would help elucidate how different microbial populations respond to varying concentrations of nitrates and other environmental factors.

Thanks a lot

Yes, heterogeneous resistance can indeed affect the zone diameter in disk diffusion susceptibility testing.

In disk diffusion susceptibility testing, antimicrobial susceptibility of bacteria is assessed by measuring the zone of inhibition around an antimicrobial disk on a culture plate. The diameter of this zone is indicative of the susceptibility of the bacteria to the antimicrobial agent.Heterogeneous resistance refers to the presence of subpopulations of bacteria within a culture that exhibit varying degrees of susceptibility to the antimicrobial agent being tested. This means that while the majority of the bacteria may be susceptible to the antimicrobial, there could be small subpopulations that are resistant.When performing disk diffusion testing, if there are subpopulations of resistant bacteria within the culture, the zone of inhibition may appear larger than expected. This is because the susceptible bacteria surrounding the resistant subpopulations are still inhibited by the antimicrobial, leading to a wider zone of inhibition. As a result, the zone diameter may not accurately reflect the true susceptibility of the bacterial population as a whole.

Robert Adolf Brinzer I was speaking about mutations instead of phenotypic variations. It's my bad, i think should rewrite the question for clarity.

I don't think incubator function would have an effect on growth in broth. Can you offer more info? The microbes and broth?

Bacterial metabolism is abroad term,fist of all put your isolate on group of classification according to Bergy .manual for clssifactin of bacteria

I agree with Roget Bayston. add Neisseria catarrhalis normal flora in pharynx as well as diphtheroid.

Salah A. Alshehade Thanks for answering. Do you have some more information about these adapters? As you mentioned, there are multiple 10-15 mL tubes that fit biomerieux densitometers, but they are too high and because of that withdrawing liquid with automatic pipettes is impossible..

You can observe the Margin (entire, undulate, or lobate), Elevation which can be flat, raised, convex, or umbonate, and Texture whether the surface appearance of the colony is smooth, rough, wrinkled, or granular.

You can also observe the degree of transparency or opacity of colonies.

Observe and compare the rate growth of the two colony types. If you have information on the types of nutrients that the organisms use, you can perform additional tests to see if the two colony types show differential growth of these nutrients

If possible, perform microscopic examinations of the colonies to look for differences in cell morphology or structures.

Hi Mohammad, you can find biochemical tests differentiation for these bacteria in this paper:

Simon

There could be several possible reasons why no bands are observed in the PCR amplification of 16S rRNA of E.coli genes:

These video playlists might be helpful to you:

Yes. Sorry for my late reply.

I am using API 20 NE to ID such strain in my lab.

In fact, i am seeing many strongly oxidase positive GNB with TSI Acid/Acid profile.

In Table 7.1. First stage table for Gram Negative bacteria of Cowen & Steel, it clearly show that 7.9 Enterobacteria are oxidase negative.

For most commercially availabe semiauto and automatic bacteria Id kits and devices, the researchers may still need to sort out the genus of the target organisms.

For those scientsts working at well developed sequencing facilities, it would be nice to seqence, identify and report such interesting strains.

I think we do need to first check oxidase activity when we are identifying GNB now.

Hello,

Kindly always ensure proper aseptic techniques. This is the first line of obtaining reliable results in bacteriology.

All the best

Open the researchgate page or the article and on the right side press on more to show dropdown menu and select edit. You will get the option to change the tittle and save.

Hello, there were many ways from which the most important is internal quality control which can reduce risks as well as increase the reliability of data received. If no any knowledge to create your own internal control you can follow any international requirements of GLP mainly good laboratory practice in microbiology.

Hope this can help you!

Here are some effective methods for reducing the risk of cross-contamination:

According to studies, this is due to the bacterial yield as the sample size increases such as for every 1 ml of blood. However, pediatric patients may suffer from anemia from extracting too much.

https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(19)30533-6/pdf

A simple method:

Obtain a pure culture broth of P. aeruginosa.

Centrifuge the broth.

Separate the supernatant.

Add chloroform to the supernatant.

Keep it for settlement.

Add HCl. It will turns into pink/red. Again keep for settlement.

Add NaOH, it will turns blue.

Pigment isolated.

GAS produce two hemolysins that may contribute to pathogenesis. Streptolysin O (SLO) is a well-characterized oxygen-labile prototype of a cholesterol-binding bacterial exotoxin. When cultured in broth, GAS express SLO during exponential-phase and early stationary-phase growth (1). Streptolysin S (SLS) is an oxygen-stable oligopeptide primarily responsible for the characteristic zone of beta-hemolysis surrounding GAS colonies grown on blood-agar medium (copied from )

Yes you can.

You may also consider precipitation/crashing of compound at higher concentration also.....which will make it unavailable to cells, if that is case.

Hope that helps!

I support the views raised by Prof.Phil Geis.

Blood is the most common clinical sample when it comes to bacteriology because in the case of septicemic disease can used for culturing and isolation of causative agent also serum can be separated from blood can be used for rapid diagnosis which give suggestive diagnosis .....etc

This is the procedure I use for E. coli stocks:

- Take a freshly saturated culture in rich medium (2YT or LB) and spin 2 ml in a 2-ml microfuge tube for 2 min in a microcentrifuge.

- Discard 1 ml of the supernatant and use the remaining 1 ml to resuspend the pellet

- To the concentrated suspension, add 0.5 ml 60% (v/v) sterile glycerol and mix thoroughly by pipetting up and down.

-Transfer the mixture to a cryotube and store at -80 °C

I have kept such viable stocks for decades. When needed, scratch the surface of the frozen stock with a toothipck and use the scratched material to inoculate a fresh culture, without thawing the rest of the stock, which should be returned immediately to the -80°C freezer.

Manuel Madrazo

Thanks a lot, can you suggest to me some specific work ideas.

Oxidase negative

Hi Richard, Did you do API 20E for Pseudomonas?

It's crystals from salt in your buffer. You need to fix your specimen and thoroughly wash it with water to get rid of any salts.

When transporting glassware from one place to another, I do not think that you can avoid contamination 100%, but as much as possible it can be reduced by wrapping these utensils with sterile cellophane and transporting them with the dishes in a sterilized container, knowing that it is better to transfer bacteria through transport media. In general, if you use special selective culture media, you do not need to worry, because such media will prevent the growth of any species other than the one you are investigating.

You perform Gram reaction with crystal violet on pure cultures and not mixed cultures. So, please purify your cultures and apply the crystal violet to what you want. The cell culture techniques is a different protocol entirely.

I agreed with Wafaa Eltayeb.

I agree with the accurate answer of Dr. Sandhya Jayasekara. She gave almost all the bacterial species that are transported in the water and may pose a public health concern, and I would like to add Aeromonas to them, it is also possible to be transmitted by water and Giardia parasite ... And indeed there is resistance against chlorine in addition to the danger of chlorine because it causes, after its interaction with the organic materials present in the water, from the production of chlorine byproduct, which is the most dangerous of which is trihalomethanes. Indeed, it is possible to treat water with UV radiation, which is an effective method against germs, and it is possible to use ozone then filtering with active biological carbon and then chlorine because here we have implied the purity of water from the remnants of organic materials by filtering and implying that even if a few microorganisms remain after treatment with ozone, it will not reproduce due to filtration of organic matter. Because if we left it unfiltered after the ozone treatment, the remaining micro-organisms might grow rapidly and may cause health problems.

In stationary phase living cells number are equal to dead cells and there are many secondary products

Hi Elvira,

I also observed the change of aspect of Gardnerella vaginalis in the same condition. Is this normal? or how to solve this ? Elvira Marín

Also, my Gardnerella vaginalis cannot grow in the BHI broth at 37 ˚C, 50% CO2.

You can try annotating your genome with tools like PROKKA, PGAP or RAST. And look at the predicted genes and other features

It all depends upon what you intend to do with them. If you are just storing them and then plan to streak them out again later, strains should last for months at 4C. However if you want to actually do experiments on the cells you are storing, then probably 24 hours at most before you start having physiological changes.

Note that with E. coli strains if the strain is a recA- strain (like many cloning strains), then their lifespan is MUCH shorter and you will start getting significant cell death in a week or two at 4C.

It seems to be an answer:

https://advances.sciencemag.org/content/6/46/eabc4516 Repeated gain and loss of a single gene modulates the evolution of vascular plant pathogen lifestyles BY EMILE GLUCK-THALER, AUDE CERUTTI, ALVARO L. PEREZ-QUINTERO, JULES BUTCHACAS, VERÓNICA ROMAN-REYNA, VISHNU NARAYANAN MADHAVAN, DEEPAK SHANTHARAJ, MARCUS V. MERFA, CÉLINE PESCE, ALAIN JAUNEAU, TACA VANCHEVA, JILLIAN M. LANG, CAITILYN ALLEN, VALERIE VERDIER, LIONEL GAGNEVIN, BORIS SZUREK, GREGG T. BECKHAM, LEONARDO DE LA FUENTE, HITENDRA KUMAR PATEL, RAMESH V. SONTI, CLAUDE BRAGARD, JAN E. LEACH, LAURENT D. NOËL, JASON C. SLOT, RALF KOEBNIK, JONATHAN M. JACOBS

SCIENCE ADVANCES13 NOV 2020 : EABC4516

Abstract Vascular plant pathogens travel long distances through host veins, leading to life-threatening, systemic infections. In contrast, nonvascular pathogens remain restricted to infection sites, triggering localized symptom development. The contrasting features of vascular and nonvascular diseases suggest distinct etiologies, but the basis for each remains unclear. Here, we show that the hydrolase CbsA acts as a phenotypic switch between vascular and nonvascular plant pathogenesis. cbsA was enriched in genomes of vascular phytopathogenic bacteria in the family Xanthomonadaceae and absent in most nonvascular species. CbsA expression allowed nonvascular Xanthomonas to cause vascular blight, while cbsA mutagenesis resulted in reduction of vascular or enhanced nonvascular symptom development. Phylogenetic hypothesis testing further revealed that cbsA was lost in multiple nonvascular lineages and more recently gained by some vascular subgroups, suggesting that vascular pathogenesis is ancestral. Our results overall demonstrate how the gain and loss of single loci can facilitate the evolution of complex ecological traits.

Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s). ... Antibiotics or antibacterials are a type of antimicrobial used in the treatment and prevention of bacterial infection. They may either kill or inhibit the growth of bacteria. The differences between them are:

1- Bacteriocins are produced on the surface of ribosomes in microbial cells, while antibiotics are primarily secondary metabolites of the cell.

2- Bacteriocin producers are insusceptible to the bactericidal agents, unlike producers of antibiotics.

3- Bacteriocins can attach to the target cell wall anyplace on the surface, as no specific receptors on the target cell wall apparently exist.

4- The mechanism of bacteriocin on target cells is diverse and is associated with the method of pore formation in the outer cell membrane. Bacteriocins bind to cell walls of sensitive microbes, motive ionic imbalances, and produce pores. Inorganic ions leak the target cells through the created pores and thereby killing them. Antibiotics, on the other hand, can inhibit synthesis of the subcellular processes (cell wall synthesis, intracellular protein production, and DNA and RNA replication). Their bactericidal and bacteriostatic mechanisms are diverse and may comprise pore formation, degradation of cellular DNA, disruption via specific cleavage of 16S rRNA, and blockage of peptidoglycan synthesis.

Dear Prof Diego García-Compeán , given the low virulence of Helicobacter pylori and the high prevalence of its infection worldwide, it might be the time to regard it as a commensal organism, not treat it a pathogen:

The medicines used for the eradication of H. pylori will inevitably kill other commensal organisms in the human microbiome, which might have adverse effect on our health.

Hi Marianne,

I would check out IsoHelix Xtreme DNA isolation kits. The buffer used in the extraction keeps samples shelf stable for a while and might be a good alternative to RNAlater.

You can autoclave the Yeast extract, tryptone and pH salt: K2HPO4, KH2PO4 separately. It will no precipitation anymore!

https://www.carlroth.com/medias/Info-Brochure-Phosphates-in-Media-EN.pdf?context=bWFzdGVyfHRlY2huaWNhbERvY3VtZW50c3wyNTc3MTl8YXBwbGljYXRpb24vcGRmfHRlY2huaWNhbERvY3VtZW50cy9oMzEvaDk3Lzg5NzY2Mjk5NTY2MzgucGRmfDZmMGRiOTE1YWUwYmFlZWM5M2QxZWI5ZTRkNjk2MzFmNGFjMmM0ODNiNDEzYzk5OGY0MDRkMjJiNjY5ZmEwM2Q

I think you try using the water quality index

Agree with Rudy Situmeang

Following

Please take a look at this useful link.

Bacteriocin effects on cancer cells

Brown II, Häse CC. Flagellum-independent surface migration of Vibrio cholerae and Escherichia coli. J Bacteriol. 2001 Jun;183(12):3784-90.

Berhe Mengistu your study seems partial epidemiology and partial experimental type. Remember you may want to choose simple random sampling for your epidemiology estimated with help of your local prevalence rate of mastitis by given formulas in Thursfield's book for epidemiology. As for your experimental work, whatever experimental design you may choose, you should have minimum six replicates of each treatment.

Good luck

Aerobic and anaerobic bacteria can be identified by growing them in test tubes of thioglycollate broth: 1: Obligate aerobes need oxygen because they cannot ferment or respire anaerobically. They gather at the top of the tube where the oxygen concentration is highest. 2: Obligate anaerobes are poisoned by oxygen, so they gather at the bottom of the tube where the oxygen concentration is lowest. 3: Facultative anaerobes can grow with or without oxygen because they can metabolise energy aerobically or anaerobically. They gather mostly at the top because aerobic respiration generates more ATP than either fermentation or anaerobic respiration. 4: Microaerophiles need oxygen because they cannot ferment or respire anaerobically. However, they are poisoned by high concentrations of oxygen. They gather in the upper part of the test tube but not the very top. 5: Aerotolerant organisms do not require oxygen as they metabolise energy anaerobically. Unlike obligate anaerobes however, they are not poisoned by oxygen. They can be found evenly spread throughout the test tube.

the brown pigment is probably pyomelanin. I have seen something similar in other species, but interestingly the pigment turns brown upon exposure to air, a bit like an apple browning after being cut. The pigment is formed where there are chromosomal deletions in genes associated with tyrosine metabolism, that leads to an accumulation of the pigment.

Hello, Doroteja Vaitiekunaite

The picture is more or less typical for bacterial carbohydrate fermentation test

Phenol red is yellow at a pH < 6.8 and red at a pH of > 7.4, therefore if a bacterium ferments a sugar to acid a yellow color will develop.

On picture

A) Formation of acid and gas.

(B) Formation of acid,

(C) inoculated control,

D) alkaline byproducts,

(E) no acid or gas formation.

So you have acid and low alkaline formation in your tubes.

The orange color in the tube, this represents a pH > 6.8 and should not be considered as positive. The yellow tubes are positive.

Hope my explanation is clear.

Good luck  

Probably a little too late, I dont now what you intend to do with this, but I have found that sonication for 30s and centrifugation (33,000 x g) could remove the cell pellet from the Exopolymeric substances. This are really old techniques, and there are more depending on your needs. There are many papers that explain these methods, personaly I liked this one: "Comparison of bacterial extracellular polymer extraction methods by M.J. Brown and J.N. Lester, 1980"

You can use selective media for bacteria Isolation, please see in attach file.

Establishing the relationship of Double J stent Catheters with the episodes of CAUTI and CRBSI and subsequently link its prolonged exposure leading to bacterial translocation as a risk factor for the development of the sepsis.

A single log reduction is a 90% reduction of organisms. A two log reduction is a 99% reduction of organisms, followed by a three log reduction (99.9%) etc.

Microbial consortium: is two or more microbial groups living symbiotically. Consortiums can be endosymbiotic or ectosymbiotic. Symbiosis is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. The organisms may be of the same or of different species.

Symbiosis can be:

obligatory: one or both of the symbionts entirely depend on each other for survival.

facultative (optional): they can generally live independently.

Mixed-culture consists of two or more organisms. Mixed cultures can consist of known species to the exclusion of all others, or they may be composed of mixtures of unknown species. The mixed cultures may be all of one microbial group—all bacteria—or they may consist of a mixture of organisms of fungi and bacteria or fungi and yeasts or other combinations in which the components are quite unrelated. Soil, for example, is a mixed-organism environment with protozoa, bacteria, fungi, and algae growing in various numbers and kinds, depending on the nutrients available, the temperature, and the pH of the soil.

Kindly see the following RG links.

Thanks for all the tips! This was extremely helpful

Dear Sadegh Khorrami ,

This seemingly easy to answer question is rather complicated.

Gram-positive and gram-negative bacteria have differences in their membrane structure but it is clear that most of them have a negative charge.

The gram-negative bacteria have a layer of lipopolysaccharide at the external surface followed by a thin layer of peptidoglycan while the cell wall in gram-positive bacteria is mainly composed of a thick layer of peptidoglycan.

It has been shown, using zilver nanoparticles (AgNP), that the AgNPs were more active against gram-negative bacteria and since the electrostatic attraction between positively charged nanoparticles and negatively charged bacterial cells is shown to be an important aspect with regard to the antimicrobial activity of the AgNPs this suggests that Gram-negative bacteria have the highest negatively charged cell wall.

However the MIC against E. coli was found to be the lowest determined concentration among bacterial strains for positively charged AgNPs and therefor seem to suggest that the actual negatively charge vary a lot and depend on the characteristics of the bacterial species.

See for details on all this:

Abbaszadegan, A., Ghahramani, Y., Gholami, A., Hemmateenejad, B., Dorostkar, S., Nabavizadeh, M., & Sharghi, H. (2015). The effect of charge at the surface of silver nanoparticles on antimicrobial activity against gram-positive and gram-negative bacteria: a preliminary study. Journal of Nanomaterials, 16(1), 53.

There is another reason why this question is not easy to answer, and I quote:

“As surface charge and surface potential both vary on a charge-regulated surface, accurate modeling of bacterial interactions with surfaces ultimately requires use of an electrostatic model that accounts for the charge-regulated nature of the cell surface.”

See for details:

Hong, Y., & Brown, D. G. (2008). Electrostatic behavior of the charge-regulated bacterial cell surface. Langmuir, 24(9), 5003-5009.

Yes. Please see the following RG links.

Be sure that staining procedure is made accordingly and when taking smear should be from isolated colony to avoid possible sampling from two different colony forming unit adjacent to each other

Hi,

You need some biochemical tests.

Let me ask a question - I am assuming you are an undergraduate student, and do you need to do a laboratory based research project or a library written paper as this makes a big difference in what we should suggest. If a lab research project, how much time are you supposed to devote to it, and what type of facilities and equipment do you have to use?

OK

Dear Raheleh

Tri calcium phosphate is always an water insoluble compound under normal pH conditions. That is why you should sterilize it separately as dry powder in the same autoclave when you sterilize the agar or liquid medium. Then just before pouring plates (in case of agar medium) or inoculation of the liquid medium add the powder tri-calcium phosphate in the well cooled medium, shake well to disperse as evenly as possible and proceed.

Hello, no microbial grow without carbon source. But it can be if your bacteria fix carbon dioxide found in the air into reduced carbon, which can be used in all of the various essential metabolic processes.

Hi,

The MPN method gives good idea about the coliform bacteria and correct numbers of this bacteria.

I only had success myself using this method when I used Ruthenium Red from Sigma. I used one from Acros Organics originally and even though same formula, weight and CAS# received totally different results. Your agar should be pink to red. The plates should also be protected from light.

Hi Jeff

You were asking what lab I work in. I work in a diagnostic lab, in other words, I work in a lab were samples are sent to us from veterinary clinics across the Maritimes and we provide clinical results for the veterinarians to diagnose the issues their patients are having. We do help with running samples for researchers but this is more often for aquatic and Agricultural samples then for small animal research. So in my job I see a lot of samples come through our lab for patients being checked for DCM due to the diets they are on.

So I have no involvement with the pet food industry in my job and I am not influenced by them either.

Pseudomonas aerugiunosa is a very poor control for a non-coliform, because it is not even a member of the same family any more (of course, it non-coliform then, but is also very far apart in all other properties form coliforms!). Therefore, you should look for non-pathogenic species within the Enterobacteriaceae, A possible choice may be Shimwellia blattae (formerly Escherichia blattae), which should be non-coliform (no lactose degradation according to Bergey's Manual). For positive controls, there are many non-pathogenic strains of E. coli available (e.g. the original strain K12).

So you use same media used in hospital?

If same sample shows different reaction with your media and hospital,s media, just check with them. Maybe you miss something.

Agree with Alejandro Martin's explanations.

As well, worth considering, that lysogen-independent spontaneous mutations in host genes coding for cell surface receptors of phage will occur, contributing to turbid plaque appearance.

From research report notably the study of accelerated microbial - induced CaCO3 precipitation a defined co-culture of ureolytic Sporosacina and non - ureolytic bacteria Bacillus subtilis . Result obtained indicated that the presence of the non - ureolytic bacterial species , B. subtilis accelerated the MICP process, via the supply of nucleation sites in the form of non - ureolytic bacterial cells. For more details consult www.biogeosciencs.net/11/256/2014/

doi:10.5194/bg-11-2561-2014