This is an archived Horseadvice.com Discussion. The parent article and menus are available on the navigation menu below:
HorseAdvice.com » Diseases of Horses » Respiratory System » Chronic Lower Airway Disease »
  Discussion on Has anyone dealt with a gram-negative bacterium called Stenotrophomas Maltophilia?
Author Message
New Member:
beebede1

Posted on Friday, Sep 10, 2010 - 8:23 pm:

Hi/Help!
My vet and I are at wits-end about how to deal with what has turned into a chronic cough in my otherwise healthy, 13 year old Morgan mare.

Background:
1. In June 2009, this mare had major abdominal surgery (in the state of Vermont) to remove an ovary with a large granulosa cell tumor. Other than the obvious testosterone associated issues (gender confusion) prior to the surgery, this mare had always been 100% healthy. NOTE: The mare has had annual dental care and vaccinations for the 9 years I’ve owned her.

2. The mare had an uncomplicated surgical recovery other than within a week of coming home, she started to have a cough and what seemed to be excessive salivation associated with each "coughing episode". No fever, no nasal discharge ever, no wheezing, and her eyes were always clear. Since she was on extended stall rest and very light hand-walking it could not be associated with exertion. Her feed was pristine grass hay, no dust. I watered it anyway, just to remove that as a potential irritant. I reported my concerns to the veterinary surgeon and he was unconcerned - called it irritation from the endotracheal tube inserted for the surgery - should heal in couple weeks. When the coughing persisted longer than a couple weeks, my regular vet came out, examined her and proclaimed it to be coughing due to seasonal allergies and slobbers from a fungus in the green pasture grass (she was on pasture for 30 minutes a day).

3. In November 2009 we moved to Southern Colorado, and had the horses shipped by commercial carrier.

4. Three of my four horses got off the van in great shape, considering the stressful trip. The Morgan mare had shipping fever...

5. From November 2009 through May 2010:
- we treated her with 2 courses of Uniprim
- we scoped her in early February (unremarkable) and followed with a course of
Naxcel and Trihist, and then a course of Baytril and Ventipulmin.
- a transtrach wash done in March, cultured heavy growth of strep zoo, so we put her on Polyflex, then Uniprim again, then Sodium Iodide IV, then a guttural pouch flush, followed by a course of Benzathine Penicillin. My poor little mare was a walking pincushion!!!

After the first two courses of Uniprim in early December 2009, her lungs and sinuses were always clear and there was no wheezing.

Her symptoms would always clear while she was on the antibiotics, only to return a few weeks after her last dose.

Frustrated, I hauled her to a 3rd vet in June 2010, for another opinion.

He scoped her upper airways and guttural pouches, and did an ultrasound of her thorax - everything looked and sounded great. The scope did reveal some "very slight lymph node hyperplasia".

As a last resort, the doc decided to do another culture. The culture came back positive for "Stenotrophomonas maltophilia". HUH!? The vet hit the books and I got on the internet to see what the heck we were dealing with.

In humans, Stenotrophomonas maltophilia is typically a "hospital acquired infection"
from contaminated endotracheal tubes and tracheostomy tubes. It cannot be killed by chemical disinfection - only by autoclaving.

The only antibiotic that seems to work is tetracycline.

We found a smattering of equine studies had been done by some Danish researchers. They reported that this bacterium can be associated with chronic lower airway disease in horses. One of the reports suggested that in most/all of the horses they studied, this was a hospital-acquired infection.

So... Sorry about my long-winded story, but I think the background info is important.
She has been coughing ever since her surgery in June of 2009!!!

After reviewing the culture results, we put the mare on Doxycycline for 3 weeks. Once again, her symptoms went away for the duration of the antibiotic treatment - and for 4 weeks after. Progress yes, but she started coughing and salivating again, 2 weeks ago. We're putting her back on the Doxy for eight weeks this time. My vet is bringing her case with him to the AAEP convention in Kentucky in the hopes he can find someone that has dealt with this bacterium - successfully.

Any input/insights from Dr. Oglesby and/or the readers would be welcomed!!!
Thank you for your time and patience!

Regards,
Donna
Member:
mrose

Posted on Saturday, Sep 11, 2010 - 2:06 am:

https://emedicine.medscape.com/article/237024-treatment

Have you come across the above info? If not, perhaps it will be of some help. This relates to humans, but the drugs used would be the same as used in horses I believe. The article suggests trimethoprim-sulfamethoxazole. Has that been tried?

I hope you find answers and are able to help her.
Moderator:
DrO

Posted on Saturday, Sep 11, 2010 - 8:47 am:

Hello Donna,
If the next course of Doxy does not eliminate the infection you should reculture and find what the organism is now sensitive to. This may have changed since the last culture. Sara, the Uniprim is a potentiated (trimethoprim) sulfa drug. Of course dosages and timing are critical and differ with different formulations so that should be reviewed.
DrO
New Member:
beebede1

Posted on Monday, Sep 13, 2010 - 11:55 pm:

Hi Sara!
Thanks so much for responding to my posting.
The article you sent was very interesting.
There doesn't seem to be much out there on the web, so anything I can find is much appreciated. There's just about nothing on horses, but what I did find makes me wonder if there could be more horses out there with "chronic lower airway disease" that might have more treatment options than previously thought. This bacteria has a reputation for being tenacious and untouchable by many of the systemic antibiotic protocols - that's why the next step was to go back on Doxycycline for 8 more weeks... The good news is that the mare isn't really sick - just inconvenienced. She has a coughing episode in the morning when she sees me heading to the barn for breakfast, and then maybe once more during the day. There doesn't seem to be anything in particular I can do to "make" her cough! My vet has given me the green light to ride her, and we go for leisurely trail rides and school in the arena (with no coughing!!). While I'm hopeful we'll get a 100% cure, at this point, I'm also resigned to the fact that we'll be dealing with this long-term. This little mare is part of the family, so she's here forever.

Thanks again!!
Donna
New Member:
beebede1

Posted on Tuesday, Sep 14, 2010 - 12:06 am:

Hi Dr. O!
Thanks to you also, for your quick response.
I will relay your recommendation to my vet about redoing the culture and sensitivities after this next round of antibiotics. We talked yesterday, and he also wants me to try putting her on HyDrOxazine for at least a couple weeks, just in case there's some kind of an allergic component.
I guess in this part of the country (CO), he gets much better results with HyDrOxazine than the Trihist. So we'll see! I really enjoy this website and the opportunity to share and exchange info (and support) with the great minds and hearts in the horse-loving community.

Best Regards,
Donna
Member:
mrose

Posted on Tuesday, Sep 14, 2010 - 10:59 am:

Dr.O, when all else failed with my mare Libby, they put her in a hyperbaric chamber; would this work on this type of bacteria, or only on aerobic bacteria?
Moderator:
DrO

Posted on Tuesday, Sep 14, 2010 - 7:31 pm:

Sara, you have it backwards. Hyperbaric chambers as therapy for primary infections are effective against anerobic infections: those bacteria that require lower oxygen levels (think Clostridia and gangrene). Unfortunately Stenotrophomas (Xanthomonas) maltophilia is a aerobe and flourishes in a oxygen rich environment.

There is little published on what most agree is an emerging bacterial problem due to multiresistance. There is nothing I can find on equine infections but here are two relevant papers involving human infections. I do find it odd that almost all the infections around the world are reported by a single medical group...
DrO

An Med Interna. 1998 Sep;15(9):476-80.
[Clinical manifestations of Stenotrophomas (Xanthomonas) maltophilia infection]
[Article in Spanish]

Julve R, Rovira E, Belda A, Prat J, Escoms R, Albert A, Gonzalvo F.
Servicio Medicina Interna, Hospital de Sagunto, Valencia.

Abstract
OBJECTIVE: Stenotrophomonas maltophilia (SM) is a gram-negative bacillus whose incidence like nosocomial pathogen has been incremented in the last years, especially in immunocompromised patients, subjected to invasive procedures and those receiving broad-spectrum antimicrobial therapy.

METHOD: We report 15 isolations of SM between 1994-1996.

RESULTS: The criteria for SM infection were fulfilled by 9 patients (60%), and 6 patients (40%) were colonized. The mean age of the patient was 60 +/- 12 years. Major predisposing factors in infections included venous catheterization (100%), prior surgery (86%), residence in ICU (80%), prior antibiotic therapy (80%) and intubation (66%). The most common underlying disease were heart disease (60%), treatment with immunosuppressors and/or steroids (46%) and chronic lung disease (46%). Ten cases (66%) had polymicrobial culture. The mortality rate was 40%. Risk factors associated with fatal outcome included the following: chronic lung disease (p = 0.043), nasogastric catheterization (p = 0.01), urinary tract catheterization (p = 0.02), intubation (p = 0.04) and the presence of pneumonia or sepsis by SM (p = 0.02). The most active agents were colistina (100%), cotrimoxazol (71%) and ceftazidima (53%). The isolates were highly resistant to first and second-generation cephalosporins (100%) tetracyclines (86%), aztreonam (91%) and imipenem (71%).

CONCLUSION: SM cause a wide range of clinical synDrOmes and is more likely to cause infection or colonization in patients who have underlying disease. Due to its inherent multiple-antimicrobial resistance, it would appear its potential as a nosocomial pathogen will continue to increase. Therapy of patients should include cotrimoxazole.

An Med Interna. 1998 Sep;15(9):476-80.
[Clinical manifestations of Stenotrophomas (Xanthomonas) maltophilia infection]
[Article in Spanish]

Julve R, Rovira E, Belda A, Prat J, Escoms R, Albert A, Gonzalvo F.
Servicio Medicina Interna, Hospital de Sagunto, Valencia.

Abstract
OBJECTIVE: Stenotrophomonas maltophilia (SM) is a gram-negative bacillus whose incidence like nosocomial pathogen has been incremented in the last years, especially in immunocompromised patients, subjected to invasive procedures and those receiving broad-spectrum antimicrobial therapy.

METHOD: We report 15 isolations of SM between 1994-1996.

RESULTS: The criteria for SM infection were fulfilled by 9 patients (60%), and 6 patients (40%) were colonized. The mean age of the patient was 60 +/- 12 years. Major predisposing factors in infections included venous catheterization (100%), prior surgery (86%), residence in ICU (80%), prior antibiotic therapy (80%) and intubation (66%). The most common underlying disease were heart disease (60%), treatment with immunosuppressors and/or steroids (46%) and chronic lung disease (46%). Ten cases (66%) had polymicrobial culture. The mortality rate was 40%. Risk factors associated with fatal outcome included the following: chronic lung disease (p = 0.043), nasogastric catheterization (p = 0.01), urinary tract catheterization (p = 0.02), intubation (p = 0.04) and the presence of pneumonia or sepsis by SM (p = 0.02). The most active agents were colistina (100%), cotrimoxazol (71%) and ceftazidima (53%). The isolates were highly resistant to first and second-generation cephalosporins (100%) tetracyclines (86%), aztreonam (91%) and imipenem (71%).

CONCLUSION: SM cause a wide range of clinical synDrOmes and is more likely to cause infection or colonization in patients who have underlying disease. Due to its inherent multiple-antimicrobial resistance, it would appear its potential as a nosocomial pathogen will continue to increase. Therapy of patients should include cotrimoxazole.
Member:
mrose

Posted on Tuesday, Sep 14, 2010 - 7:52 pm:

Thanks, Dr.O. I knew the chamber worked on anerobic bacteria, but was wondering if it had any effect on other bacteria as well.

It IS weird that all the infections are reported by one agency. I wonder why not by CDC also? I just read an article about a very resistant (human) but that is from India and now showing up in country. I should go back and see who reported on it originally. My overly suspicious mind always wonders if they are selling a drug that supposedly works on the bacteria when nothing else will.
New Member:
beebede1

Posted on Tuesday, Sep 14, 2010 - 8:35 pm:

Hi Dr. O ,
Because the weblinks are unreliable, I've attempted to copy some of the text/credits from a couple articles I found. They also sound like they came from the same source...
Thanks for your continued interest!!
Donna

ARTICLE 1

Vet J. 2009 Sep 14. [Epub ahead of print]

Association of Stenotrophomonas maltophilia infection with lower airway disease in the horse: A retrospective case series.
Winther L, Andersen RM, Baptiste KE, Aalbæk B, Guardabassi L.

Department of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, Denmark.

Abstract
Stenotrophomonas maltophilia is being reported with increasing frequency as a human nosocomial pathogen, especially among immuno-compromised patients. To the authors' knowledge, this pathogen has not previously been associated with lower airway disease in the horse. In this paper the clinical findings, laboratory diagnosis and response to treatment of seven cases of respiratory infection with S. maltophilia in horses, presented at three equine referral hospitals in Denmark in 2007, are described. In all cases there was a clinical history of chronic coughing and abundant mucopurulent exudate was observed in the lower trachea on endoscopy. On culture of tracheal aspirate, grey, slow-growing colonies, identified as S. maltophilia by both API 20NE identification and 16s ribosomal DNA sequencing, were identified. All isolates had a similar antibiotic susceptibility pattern characterised by resistance to all penicillins and cephalosporins, and to imipenem, gentamicin, amikacin and rifampicin. Ribotyping and pulsed-field gel electrophoresis of the S. maltophilia isolates from different patients indicated that they were either indistinguishable or closely related. This study indicates that S. maltophilia can be associated with chronic lower airway disease in the horse and provides useful initial insights into the diagnosis, therapy and epidemiology of this novel condition.

PMID: 19758829 [PubMed - as supplied by publisher]


ARTICLE 2

From TheHorse.com
Researchers Describe New Equine Respiratory Condition
by: Stacey Oke, DVM, MSc
October 08 2009, Article # 15035

The bacterium Stenotrophomonas maltophilia can be associated with chronic lower airway disease in horses, reports a group of Danish researchers.

S. maltophilia is a Gram-negative bacterium that is causing disease more often in humans, particularly among the immunocompromised population, but it is only rarely reported as causing infection in animals.

The research team led by Lotte Winther, a PhD student in the Department of Large Animal Sciences, Faculty of Life Sciences at the University of Copenhagen, noted "S. maltophilia has only once been reported as an equine pathogen."

In 2007 Winther and colleagues collected data from seven horses with respiratory infections from which S. maltophilia was cultured. In all cases chronic coughing and an exudate composed of both mucus and pus was noted in the lower trachea during endoscopic examinations. DNA testing indicated that all seven horses were infected with the same or very similar types of the bacterium, and S. maltophilia cultured from the tracheas of affected horses were resistant to a wide variety of antibiotics, including:

•All penicillins and cephalosporins;
•Imipenem;
•Gentamicin;
•Amikacin; and
•Rifampin.
Together, the data suggest that S. maltophilia can act as a respiratory pathogen and should be considered in horses with a history of respiratory signs and with abundant mucopurulent material in the trachea.

The authors emphasized that commonly administered antibiotics for equine respiratory infections are not active against S. maltophilia.

"Prolonged administration of tetracyclines (greater than 10 to 14 days) is an effective treatment, especially for adult horses," advised the researchers.

Additional details regarding the disease are described in the study, "Association of Stenotrophomonas maltophilia infection with lower airway disease in the horse: A retrospective case series," which is scheduled to be published in an upcoming edition of The Veterinary Journal. The abstract is available on PubMed.
Home Page | Top of Page | Join Us!
Horseadvice.com is a BBB Accredited Business. Click for the BBB Business Review of this Horse Training in Stokesdale NC