urgent - TERM EN snail and thread

[Guest guest]

Hello everybody.

Talking about bacterial shape, has anybody an idea of what shape is the

following?

" ...a thin snail and thread shape "

Is this a filamentous helix/spiral? A sinuous filament?

To be honest, bizarre shapes come to mind, also... (pastoral staff).

It's urgent. Thanks in advance,

Giovanna

[Guest guest]

Hello Giovanna,

It seems to depend on which bacteria it is but this might help.

Best,

3. Examples:

1. Consider rod shaped to be default for a bacterium. That

is, if you don't know what shape a bacterium is, your best bet is to

just go with rod.

2. Examples otherwise include:

1. Bacillus anthracis

2. Bacillus subtilis

3. Chlostridium botulinum

4. Chlostridium perfringens

5. Chlostridium tetani

6. Escherichia coli

7. Haemophilus influenzae

8. Klebsiella spp.

9. Lactobacillus spp.

10. Legionella spp.

11. Listeria monocytogenes

12. Mycobacterium leprae

13. Mycobacterium tuberculosis

14. Pasteurella pestis

15. Proteus spp.

16. Pseudomonas spp.

17. Salmonella spp.

18. Serratia marcescens

19. Shigella spp.

20. Yersinia pestis

21. In addition to this list is Vibrio cholerae, which

is a curved rod.

4. See illustration below.

# Diplobacilli

1. Paired rods:

1. Bacilli that remain in pairs after they divide.

2. See illustration below.

# Streptobacilli

1. Bacilli that fail to separate after they divide, but instead

remain in chains of cells.

2. Example: Bacillus megaterium

3. See illustration below.

# Coccobacilli

1. Ambiguous designation:

1. A short Bacilli that nearly looks like a cocci.

2. A shape that exists simply to show that bacteria are so

diverse that even characterizing them by shape is ambiguous?

2. Example: Bordetella pertussis

3. See illustration below.

# Illustration, bacilli

# Additional bacterial shapes

1. Additional bacterial shapes include:

1. Budding Hyphomicrobium spp.

2. Commas

1. Bdellovibrio spp.

3. Corkscrews

4. Helical

1. Borrelia burgdorferi

2. Helicobacter pylori

3. Treponema pallidum

5. mycelium (hyphae)

1. Actinomycetes

2. Hyphomicrobium spp.

6. spirillum (rigid, wavy spirals)

7. spirochetes (flexible spirals)

1. Borrelia burgdorferi

2. Treponema pallidum

8. squares

9. stars

10. etc.

2. See, for example, the illustration of a spirochete below.

# Illustration, spirochete

# Monomorphic

1. A trait of a bacterium that tends to display the same shape

regardless of physiological or environmental conditions.

# Pleomorphic [polymorphic, pleiomorphic]

1. A trait of a bacterium that can display different shapes under

different physiological or environmental conditions, or even in the

same culture.

2. Examples:

1. Corynebacterium diphtheriae

2. Mycoplasma pneumoniae

3. Rickettsia prowazekii

4. Rickettsia rickettsiia

3. Note that both Corynebacterium diphtheriae is a pleimorphic rod.

# Vocabulary

1. Bacilli

2. Bacilli, illustration

3. Bacillus

4. Additional bacterial shapes

5. Cocci

6. Cocci, illustration

7. Coccobacilli

8. Coccus

9. Diplobacilli

10. Diplococci

11. Monomorphic

12. Pleomorphic

13. Polymorphic

14. Sarcinae

15. Spirochete, illustration

16. Staphylococci

17. Streptobacilli

18. Streptococci

19. Surface to volume ratio

20. Tetrad

# Practice questions

1. Draw in outline and label (i) streptobacilli, (ii) diplococci,

and (iii) staphylococci (make sure I can tell the difference between

your cocci and bacilli). [PEEK]

2. You observe a culture of predominantly round (presumably

spherical) bacteria that though apparently fully divided, nevertheless

have failed to separate, thus resulting in long chains of cells. What,

generally, might you call such an arrangement? [PEEK]

3. Which of the following normally occurs as only individual,

spherical cells? (circle best answer) [PEEK]

1. Chlamydia trachomatis.

2. Escherichia coli.

3. Bacillus subtilis.

4. Clostridium tetani.

5. Helicobacter pylori.

6. Treponema pallidum.

4. In terms of planes of division, describe why Micrococcus luteus

forms tetrads rather than streptococci.[PEEK]

5. Circle all of the spiral or helical-shaped bacteria. [PEEK]

1. Bacillus anthracis, Bacillus subtilis, Bdellovibrio spp.,

Bordetella pertussis, Borrelia burgdorferi, Chlamydia trachomatis,

Clostridium botulinum, Clostridium perfringens, Clostridium tetani,

Corynebacterium diphtheriae, Escherichia coli, Helicobacter pylori,

Hemophilus influenzae, Klebsiella spp., Lactobacillus spp., Legionella

spp., Listeria monocytogenes, Mycobacterium leprae, Mycobacterium

tuberculosis, Mycoplasma pneumoniae, Neisseria gonorrhoeae, Neisseria

meningitidis, Pasteurella pestis, Proteus spp., Pseudomonas spp.,

Rickettsia prowazekii, Rickettsia rickettsii, Salmonella spp.,

Serratia marcescens, Shigella spp., Staphylococcus aureus,

Streptococcus spp., Treponema pallidum, Vibrio cholerae, Yersinia pestis

6. Name one pleomorphic bacterium. [PEEK]

7. Cells are generally small because __________. (circle best

answer) [PEEK]

1. this assures that they can fit in small places.

2. this assures that their plasma membrane is sufficiently large.

3. this assures that their nucleus remains in contact with

their cytoplasm.

4. phospholipids are expensive to make so are used sparingly.

5. all of the above.

6. none of the above.

8. What is the shape of Bdellovibrio spp. [PEEK]

9. Shape and arrangement in which Neisseria meningitidis is

normally found. [PEEK]

10. Describe the shape and arrangement of the cells of Neisseria

gonorrhoeae. [PEEK]

11. Distinguish Listeria monocytogenes and Vibrio cholerae in terms

of cell shape. [PEEK]

12. Vibrio cholera? [PEEK]

13. Treponema pallidum? [PEEK]

14. The shape and arrangement of __________ is diplococci. [PEEK]

1. Escherichia coli

2. Micrococcus luteus

3. Neisseria Meningitidis

4. Mycobacterium tuberculosis

5. Mycoplasma pneumoniae

6. Mycobacterium smegmatis

15. What is the arrangement of Micrococcus luteus? [PEEK]

>

> Hello everybody.

> Talking about bacterial shape, has anybody an idea of what shape is the

> following?

>

> " ...a thin snail and thread shape "

>

> Is this a filamentous helix/spiral? A sinuous filament?

> To be honest, bizarre shapes come to mind, also... (pastoral staff).

>

> It's urgent. Thanks in advance,

> Giovanna

>

>

>

[Guest guest]

Thank you, .

The bacterium is B. licheniformis, and the sentence is

" [b. licheniformis] has a thin snail and thread shape in the exponential

phase "

[Note: as opposed to the shape of another Bacillus.]

As far as I know, B. licheniformis is a sporigenous rod shaped bacterium,

whose cells may form long chains. Any idea?

TIA,

Giovanna

2008/11/15 athene20042002

> Hello Giovanna,

>

> It seems to depend on which bacteria it is but this might help.

> Best,

>

>

> 3. Examples:

> 1. Consider rod shaped to be default for a bacterium. That

> is, if you don't know what shape a bacterium is, your best bet is to

> just go with rod.

> [...]

>

[Guest guest]

Hello Giovana

Do you think your original text may have been wirtten/translated by a

non-English native author? " snail and thread " sounds odd. I suspect

you're correct in thinking of a spiral/coil shape, - perhaps the thread is

a tail. Just guessing in this case, but the inappropriate use of " snail "

is something I've come across before.

All the best

Owen

At 21:53 15/11/2008 +0100, you wrote:

>Hello everybody.

>Talking about bacterial shape, has anybody an idea of what shape is the

>following?

>

> " ...a thin snail and thread shape "

>

>Is this a filamentous helix/spiral? A sinuous filament?

>To be honest, bizarre shapes come to mind, also... (pastoral staff).

>

>It's urgent. Thanks in advance,

>Giovanna

>

>

>

[Guest guest]

Owen wrote:

> Do you think your original text may have been wirtten/translated by a

non-English native author? " snail and thread " sounds odd. <

Yes, it's really odd, and the author is a non-native English speaker.

> I suspect you're correct in thinking of a spiral/coil shape, - perhaps the

thread is a tail. Just guessing in this case, but the inappropriate use of

" snail " is something I've come across before. <

A snail shell is a conical " helix " , in fact, but I suspect that " snail " here

means " spiral " (planar curve).

Yes, a coil with a tail is what I thought of. Then doubts came. As I said in

a previous message, what I know of B. licheniformis is that it is a

sporigenous rod-shaped bacterium that forms chains (threads?) in its

exponential growth phase.

I wonder whether " snail and thread " could be a mistyping for " snail end

thread " , meaning a thread with a snail-shaped end. It would be odd as well,

but...

Thank you, Owen.

Giovanna

[Guest guest]

Hi,

It's not a spiral, as this bacteria is not a spirochete (in French).

May be they are speaking of the spores' appendix :

See that - last paragraph - (on :

http://www.bacterio.cict.fr/bacdico/bb/bacillus.html)

- Sorry, it's in French.

La résistance des spores, constitue un problème majeur en médecine et

l'épidémiologie de certaines infections repose sur la sporulation.

Dans le domaine industriel (industries agro-alimentaires, industries du

médicament, production de matériel stérile à usage unique) se surajoutent au

phénomène de résistance les problèmes posés par l'adhésion des spores. En effet,

certaines espèces de Bacillus produisent des spores dont la surface est

hydrophobe ce qui leur permet d'adhérer fortement à divers matériaux et de

résister aux procédés de nettoyage. C'est le cas notamment des spores de ¤

Bacillus cereus qui s'attachent très bien aux surfaces en acier inoxydable et

qui posent de graves problèmes dans les industries alimentaires. Les structures

impliquées dans l'adhésion sont encore imparfaitement connues. Dans le cas de ¤

Bacillus cereus on implique la présence de filaments semblables à des pili, pour

d'autres espèces telles que Bacillus licheniformis on fait jouer un rôle à des

appendices très fins formant une sorte de feutrage autour de la spore.

Hope this help

Re: urgent - TERM EN snail and thread

Owen wrote:

> Do you think your original text may have been wirtten/translated by a

non-English native author? " snail and thread " sounds odd. <

Yes, it's really odd, and the author is a non-native English speaker.

> I suspect you're correct in thinking of a spiral/coil shape, - perhaps the

thread is a tail. Just guessing in this case, but the inappropriate use of

" snail " is something I've come across before. <

A snail shell is a conical " helix " , in fact, but I suspect that " snail " here

means " spiral " (planar curve).

Yes, a coil with a tail is what I thought of. Then doubts came. As I said in

a previous message, what I know of B. licheniformis is that it is a

sporigenous rod-shaped bacterium that forms chains (threads?) in its

exponential growth phase.

I wonder whether " snail and thread " could be a mistyping for " snail end

thread " , meaning a thread with a snail-shaped end. It would be odd as well,

but...

Thank you, Owen.

Giovanna

[Guest guest]

merci catherine.

so you suggest that thread could refer to pili. but what about the snail,

then?

af for the " spiral " , what i have in mind is not a helical shape of

individual cells (spirochetae shape), but a planar coil at the end of a

chain of cells. a single cell must be more ore less rod-shaped, since it is

a bacillus. in the last part of exponential growth, spores can be observed

in the middle of the cell. the snail can refer to the concentric aspect of

immature spores, i've seen micrographs. on the other hand, it seems that

this is not the microscopic level involved.

thank you, catherine

giovanna

2008/11/16 cgtradmed

> Hi,

> It's not a spiral, as this bacteria is not a spirochete (in French).

> May be they are speaking of the spores' appendix :

> See that - last paragraph - (on :

> http://www.bacterio.cict.fr/bacdico/bb/bacillus.html)

> - Sorry, it's in French.

> La résistance des spores, constitue un problème majeur en médecine et

> l'épidémiologie de certaines infections repose sur la sporulation.

> Dans le domaine industriel (industries agro-alimentaires, industries du

> médicament, production de matériel stérile à usage unique) se surajoutent au

> phénomène de résistance les problèmes posés par l'adhésion des spores. En

> effet, certaines espèces de Bacillus produisent des spores dont la surface

> est hydrophobe ce qui leur permet d'adhérer fortement à divers matériaux et

> de résister aux procédés de nettoyage. C'est le cas notamment des spores de

> ¤ Bacillus cereus qui s'attachent très bien aux surfaces en acier inoxydable

> et qui posent de graves problèmes dans les industries alimentaires. Les

> structures impliquées dans l'adhésion sont encore imparfaitement connues.

> Dans le cas de ¤ Bacillus cereus on implique la présence de filaments

> semblables à des pili, pour d'autres espèces telles que Bacillus

> licheniformis on fait jouer un rôle à des appendices très fins formant une

> sorte de feutrage autour de la spore.

>

> Hope this help

>

>

>

>

> Re: urgent - TERM EN snail and thread

>

> Owen wrote:

>

> > Do you think your original text may have been wirtten/translated by a

> non-English native author? " snail and thread " sounds odd. <

>

> Yes, it's really odd, and the author is a non-native English speaker.

>

> > I suspect you're correct in thinking of a spiral/coil shape, - perhaps

> the

> thread is a tail. Just guessing in this case, but the inappropriate use of

> " snail " is something I've come across before. <

>

> A snail shell is a conical " helix " , in fact, but I suspect that " snail "

> here

> means " spiral " (planar curve).

> Yes, a coil with a tail is what I thought of. Then doubts came. As I said

> in

> a previous message, what I know of B. licheniformis is that it is a

> sporigenous rod-shaped bacterium that forms chains (threads?) in its

> exponential growth phase.

>

> I wonder whether " snail and thread " could be a mistyping for " snail end

> thread " , meaning a thread with a snail-shaped end. It would be odd as well,

> but...

>

> Thank you, Owen.

> Giovanna

>

>