During S.aureus identification, it's positive in catalase test and tube coagulase test. But when we proceeded into PCR, we did not detect the femA gene. We have repeated this a few times, and same results obtained.
Please advise what bacteria can be positive in a tube coagulase test?
Add : Sample from human nose, we were performing nasal screening for MRSA.
Add : 16SrRNA and mecA were detected, but femA and lukS were not detected.
Add : Cultured the microorganism on Mannitol Salt Agar, yellowish colour and morphology similar to typical S.aureus.
There are 7 coagulase positive species of Staphylococcus, most other than S. aureus have an animal host but may not be wholly restricted to that host. They are listed below with their predominant hosts:
S. pseudintermedius - mostly found in dogs and cats.
S. intermedius - feral pigeons
S. schleiferi ss coagulans - dogs
S. delphini - dolphins, seals, horses
S. hyicus - pigs and cattle. Not always coagulase positive
S. lutrae - otters
S. pseudintermedius, intermedius and delphini are closely related and are difficult to separate phenotypically. Further studies are required to establish the host associations of each of these, other than S. pseudintermedius which predominates in dogs and cats.
There is also a sub-species of S. aureus occasionally found in sheep, S. aureus ssp anaerobius.
If any of these organisms were isolated from human specimens it is likely that they could be mis-identified as S. aureus. In particular, close human contact with pets make it likely that S. pseudintermedius could infect humans.
With respect to your isolate patient history of animal contact may be a useful guide to its identity, backed up with phenotypic typing and/or sequencing.
Staphylococcus pseudintermedius is also a coagulase-positive species from animals
There are 7 coagulase positive species of Staphylococcus, most other than S. aureus have an animal host but may not be wholly restricted to that host. They are listed below with their predominant hosts:
S. pseudintermedius - mostly found in dogs and cats.
S. intermedius - feral pigeons
S. schleiferi ss coagulans - dogs
S. delphini - dolphins, seals, horses
S. hyicus - pigs and cattle. Not always coagulase positive
S. lutrae - otters
S. pseudintermedius, intermedius and delphini are closely related and are difficult to separate phenotypically. Further studies are required to establish the host associations of each of these, other than S. pseudintermedius which predominates in dogs and cats.
There is also a sub-species of S. aureus occasionally found in sheep, S. aureus ssp anaerobius.
If any of these organisms were isolated from human specimens it is likely that they could be mis-identified as S. aureus. In particular, close human contact with pets make it likely that S. pseudintermedius could infect humans.
With respect to your isolate patient history of animal contact may be a useful guide to its identity, backed up with phenotypic typing and/or sequencing.
S. intermedius, S. delphini, S. hyicus and S. scheleiferi subsp. coagulans [Based on Topley and Wilson's Microbiology and Microbial Infections].
I have two questions:
1- Is the empirical therapy for S. aureus effective for treatment of infections caused by these bacteria?
2- Do we need to differentiate between all other possible causes? Why?
Staphylococcus agnetis, a cow-inhabiting bacterium, can also be coagulase-positive, although it truely is a coagulase-variable species.
An excellent review article relating coagulase-positive staphylococci was recently published by Savini V et al. in Res Microbiol. 2013 Jun;164(5):371-4.
Some Streptococcus faecalis and enterobacteriaceae have also been reported
Read "Coagulase-positive staphylococci: my pet's two faces."Res Microbiol. 2013 Jun;164(5):371-4. doi: 10.1016/j.resmic.2013.02.004. Epub 2013 Mar 7.
S.aureus(humans) S. intermedius and S. hyicus(animals) are tube coagulase positive. S. lugdunensis and S.schleiferi may be confused as they are slide coagulase(cllumping factor) positive
Lot's ... check out some references as old as J Bacteriol. 1965 January; 89(1): 101–105 ... and all other answers bellow. Maybe you need to check your PCR protocol? Did you do any PCR targeting another gene such as MecA?
Yersinia pestis (although gram negative) is another bug that produces coagulase and is catalase positive. Did you confirm the morphology and gram stain reaction of your sample?
You may try multiplex detection of several genes. An example in Pletinckx et al. 2012. Vet. Microbiol. 154:363-368, they simultaneously detected mecA, nuc (encoding thermonuclease) and a 16S rRNA gene region specific for S. aureus.
Twelve organisms were found to be coagulase positve
four strains of Streptococcus faecalis; two strains of S. faecalis var. zymogenes; three strains of S. faecalis var. liquefaciens; and one strain each of S. pyogenes, Escherichia coli, and Serratia marcescens.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC315554/
A wild guess from pure-culture / co-culture biofilm studies:
*Gram(+)s: S. gordonii, S. mutans, Streptococcus sanguinis, Staphylococcus epidermis, S. pneumoniae
*Gram(-)s: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis,
*Others: P.aeruginosa, S. crista, T. forsythia, T. denticola
cheers and good luck
you can evaluate the isolates for the presence of the sa442 gene by PCR.
I'm currently working on sequencing method to determine what bacteria is it.
We also got something similar kindly check this paper that i have attached.
Article Heterogeneity in femA in the Indian Isolates of Staphylococc...
Check this paper that i have attached for more details about staphylococci
I believe i have read it as Staphylococcus hyicus , which normally is associated with animals. That is the reason we consider coagulase positive Staphylococci isolated from human as Stahylococcus aureus
One Biochem test is not enough,you have to check closely at the isolates to see if its one distinct colony then use Dnase, latex aggluination
have you S. aureus with 16S, mecA, femA and lukS positive as control positive? did you run your sample with control positive?
are you sure 16S that you use is specific for S. aureus? i guess you think that any chance of contamination in your work or isolat right? i recomend you to use 23S specific species primer from this journal Straub, J. A., Hertel, C. and Hammes, W. P. 1999. A 23S rDNA-Targeted Polymerase Chain Reaction-Based System for Detection of Staphylococcus aureus in Meat Starter Cultures and Dairy Products. J. Food Prot. 62:1150–1156.
The 2 important coagulase positive Staphylococci are S. hyicus and S. intermedius. But these are the animal strains which are reactive with diluted rabbit plasma only.
S. aureus (human strains) is reactive with both pooled human plasma and diluted rabbit plasma.
The right plasma to be used for confirmation human strains is diluted rabbit plasma.
16S rRNA is positive for Staphylococcus spp. The one which is specific for S. aureus is nuc gene.
Some strains of Staphylococcus aureus can be coagulase negative though it is unusual. Some strains of Staphylococcus hyicus and Staphylococcus intermedius can be coagulase positve. Staphylococcus pseudintermedius is coagulase positive, but not until after about 22 hours.
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