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Serratia Marcescens is a human pathogenic species of Serratia. It is sometimes linked to disease in humans.  The disease is commonly known as either Serratia plymuthica, Serratia liquefaciens, Serratia rubidaea, Serratia odorifera, or Serratia fonticola.

Serratia Marcescens can be deadly in humans as documented in 1996 when the Center for Disease Control and Prevention (CDC) investigated the deaths of infants at the Baystate Medical Center in Springfield, MA. The Medical Center contacted the CDC when it discovered 32 infants infected with some form of the disease. Of the 32 infants infected, 2 babies died and others remained sick for an extended period of time. Infants are especially susceptible to invasive bacterial infections because their immune systems are unable to fully protect them.

The CDC determined the deadly bacteria was introduced to the neonatal intensive care unit of the medical center in 1994, probably transmitted by a healthcare worker or an infant patient.

In January of 1995 healthcare workers started carrying their own bottles of hand washing soap – individual 4 oz bottles. Many times the bottles were left near sinks, inverted so the opening was contacting the sink – like many people do with shampoo bottles. Investigators found the deadly Serratia Marcescens bacteria in cultures from 16 of the 52 soap bottles and the pathogen was discovered in cultures on 1 of the 15 sinks. The investigation uncovered that water was allowed to pool in and around the sink long enough for the bacteria to grow.

The Serratia Marcescens was allowed to survive in small pools of water at the sinks, and would have entered the soap bottles if the lids were not securely closed. The pathogen could then colonize the soap bottle. Tests of unopened soap bottles showed no sign of S. Marcescens.

Serratia Marcescens in a petri dishAnother very similar case occurred in United Arab Emirates in 2008, when 2 infants died from Serratia Marcenscens while in the Premature and Newborn Department of state-owned Al Wasl Hospital. Overcrowding and poor hospital staff training is believed to be the cause for not identifying the symptoms and treating the patients before it was too late.

The mother of one of the dead infants requested to move its twin brother to another hospital for treatment but was denied. Her story is very painful.

What is Serratia Marcescens: its discovery and history.
Weeping mother of infant killed by serratia marcenscensIn 1819, a Venetian pharmacist known as Bartolomeo Bizio, identified the bacterium and gave it the name Serratia Marcescens. Bizio dubbed it Serratia in honor of Italian physicist Serrati, the steamboat inventor, and Bizio decided on Marcescens (from the Latin word which means decaying) given that the bloody pigment was known to decay rapidly.

From 1906 up to the 1950s, doctors used Serratia Marcescens as biological marker for researching the propagation of microorganisms because the bacterium was usually considered innocuous. There are recorded incidents of the U.S. military testing Serratia Marcescens on U.S. citizens in the 1950s. After the military disclosed its testing, hospitals pointed to increased pneumonia diagnosis in the subsequent weeks and months, and some deaths occurred as a result. But after the 1960s, Serratia Marcescens was clearly identified as an harmful human pathogen and as pointed out in this article, it can be deadly.

Infant infected with Serratia MarcescensMany variations relating to Serratia marcescens are capable of generating a coloring known as prodigiosin, which varies in color from deep red to light red or pinkish, based on the age of the pathogen. It can develop in soil, water, bathroom facilities or in starchy food, where the pigmented bacterium are sometimes wrongly taken for blood spots. Several cases of infants infected with serratia marcescens were somewhat easier to diagnose due to the distinctive coloring.

Serratia Marcescens Symptoms

Here are some symptoms linked with Serratia Marcescens:

  • Chills
  • Fever
  • Sepsis (pus-forming bacteria in the body)
  • Infection (by pathogenic microorganisms)
  • Nausea
  • Vomiting
  • Shock
  • Convulsions
  • Bacteremia (bacteria in the blood)
  • Urinary tract infections
  • Empyema (collection of pus in a body cavity – especially around lungs and heart)
  • Lymphadenitis (inflammation of a lymphatic gland)
  • Endocarditis (inflammation of the endocardium – membrane around heart)
  • Meningitis Peritonitis (inflammation, pain and tenderness in the abdomen, vomiting, constipation, and moderate fever)
  • Respiratory distress
  • Death

Serratia Marcescens Treatment

When diagnosed with this bacteria, people ask “What is Serratia Marcescens” and are then relieved when it is treated with antibiotic therapy including ampicillin and macrolides. Most varieties of the bacterium are susceptible to amikacin, but there have been reports of resistance to gentamicin and tobramycin. However, we must not forget that S. Marcescens is deadly when not diagnosed and treated properly.

Comprehensive testing is required as new strains of the bacterium can be resistant to common treatment.

Home therapy may be an option when the patient is stable enough to be released from hospital.

50 Responses to What is Serratia Marcescens?

  • I have my nose and throat and sinuses colonised with serratia bacteria.There is a big wound in my nose which doesn´t heal and I have had it for years. I always have fefer almost 38 C and and is always tired,and sveat a lot. I was treatet with Chiprfloxacin for more than a month But it didn´t help Later I got treated with Azitromycin which didn´t help either. I got very ill of the side effects of both medicin that is to say depression and suicide thougts. Nothing helps
    My doctor says I have got the bacteria from my cats his sand box which I clean every day.It seems that my doctor has given up from treating me with antibiotica.
    Is it possible that I got the bacteria from the cat´s stool?

    • DeadlyMicrobes says:

      Please don’t lose hope. There are Serratia species that are commonly found in the intestinal organs of cats and dogs. First, take all precautions outlined in the article above like cleaning and drying any wet areas. If your cat has been sick with cramps and diarrhea or if he has an immune deficiency disease, he could be harboring S. Shigella or other Serratia species. The bacteria can spread when the cat cleans itself and bypasses the normal bacterial immune response. In this case, cleaning the cat’s sandbox won’t cure the problem.

      Please take the doctor’s recommendation to heart. I suggest you have your cat checked by a veterinarian. If there are any issues, get medications to fix them and then have him stay at a kennel or with a friend for a few weeks to see if that affects your open wound and the Serratia.

      You need to be proactive. Don’t give up and don’t do nothing.

  • Ali says:

    I’m 5 months pregnant and HIV positve .I’ve started treatment ( Astreslawin tablets) while I found out at 3 months of my pregnancy .I’m experiencing diarrhea ,is this not gonna affect my unborn child or cause miscarriage.

    • DeadlyMicrobes says:

      Hi Ali, Please consult your doctor. There are so many factors involved in a successful pregnancy and birth. Having HIV adds another dimension, not to mention the complications directly related to the disease.

  • Tami says:

    Hi. It seems from the other posts you don’t really reply quickly so I am hoping to get an answer. I have had recurring conjunctivitis for months. Been on tobrimycin but it keeps coming back. Could this serratia be the cause? I never even heard of it. I only found this when researching red ring on toilet and what it was. Is there anything that will get rid of my eye problems if that’s what it is?

    • DeadlyMicrobes says:

      Hi Tami, Recurring conjunctivitis can be caused by any number of underlying problems including Serratia Marcescens or your eye makeup. If you wear contact lenses, the likelihood of Serratia Marcescens causing conjunctivitis is high. If you do, stop wearing them for a few weeks and see what happens. Try cleaning your bedding and changing your eye makeup or stop wearing eye makeup for a few weeks.

      Good luck and keep us posted.

  • CP says:

    My fiancee has been on treatment for twelve years now. We use protection but is it safe for us to have unprotected sex? We want to have a baby.

  • Heena says:

    I have some orange stains in my sink. I wash my baby’s bottles in the sink and then put them in the steriliser. My questions are:
    1. If water splashed on to the orange stuff and then onto the bottles, can my son get an infection?
    2. If I have cuts on my hand and the water splashes from the orange stuff on to my hands, can I get an infection?

    P.S my husband is cleaning it tonight

    • DeadlyMicrobes says:

      Yes to both questions. If the pooling water has bacteria, any small splash of water can move millions of bacteria to the bottles or into your open cut. It is always best to eliminate any pools of water in your kitchen or bathroom.

    • Michael says:

      The answer to both questions is yes so use caution. Lysol is a good way to go when cleaning and killing harmful bacteria in the sink or even bleach. Always use extra caution when you have cuts. I wouldn’t give your son anything from those bottles if water splashed from the orange stuff. I would also use Lysol for your sinks, bathroom, on a regular basis to keep harmful bacteria like this away. If you’re not certain of anything the best thing to do is to ask your doctor.

    • DeadlyMicrobes says:

      Johanna, it is absolutely possible in that situation. Especially if you leave your shaver along the tub or near the sink. Any pooling water can have serratia bacteria growing. if you have symptoms as outlined on this page, please see a medical professional. Give them your symptoms and tell them what you think.

    • DeadlyMicrobes says:

      Denise, please get advice from a medical professional. It’s worth while taking the time to diagnose and treat these issues promptly.

  • Ewan Roy says:

    Have tested positive for serratia liquefaciens after about 6 months of going to doctor for abdominal pain. Had a spell in hospital with suspected sepsis and have been given gentamicin, ciprofloxacin and oflaxacin amongst others. Nothings seems to be killing the bacteria and am starting to get worried. Do you have any advice?

    • DeadlyMicrobes says:

      You did the best thing for your infection. Now I would work on finding the source of the bacteria. Was there a time recently when you changed your routine? Ate at a questionable restaurant or splashed pooled water into an open cut? Continue following the advice of your doctor and stay on the meds you’ve been prescribed.

  • Ann says:

    Have you heard of any cases of serratia colonizing in the mouth? Specifically in the gums causing breakdown of integrity of teeth, gums, mouth mucosa, etc.

    • DeadlyMicrobes says:

      Yes it’s possible. If you have specific symptoms, please see your doctor or other medical professional.

  • Marie Garrett-Chaney says:

    My husband was recently diagnosed with lung cancer. And a week later develop a bad infection which has been identified as the bacteria that you are talking about here. They have already done one round of antibiotics and have started him on a new one. He is not doing well at all. Who do I need to talk to about this So that something can be done. he is going downhill very fast.

    • DeadlyMicrobes says:

      Marie, I’m sorry for you and your husband. You are doing the right thing by having him under medical care. If you’re not comfortable with the progress, please ask your doctor to arrange for a diagnosis from an Infectious Disease Specialist. Sometimes the hospital has an expert on staff. However, it might be better to take him to a different hospital for a second opinion depending on your comfort level with the medical staff you’re currently working with.

  • Marie Garrett-Chaney says:

    My husband was recently diagnosed with lung cancer. And a week later develop a bad infection which has been identified as the bacteria that you are talking about here. They have already done one round of antibiotics and have started him on a new one. He is not doing well at all. Who do I need to talk to you about this right. So that something can be done. She is going downhill very fast.

  • Teresa E says:

    I had a lumpectomy x2 2 weeks apart both times i caught an infection the 2nd infection i was hospitalized abscess, cellulites, sepsis (culture 3+ Serratia Marcescens with 4+ WBC’s Gram Stain.
    They drained the 1st day 250cc plus and continued for months to drain. I also developed a blood clot that remained for a addition 3 months for which the Serratia continued to flare and continued to drain fluid until I was able to under go reconstruction surgery 5 months after the second surgery.
    The hospital for which I had my surgery has said I contracted the Serratia on my own, that it comes from the bathroom that it can be contracted from anywhere. But I see your post dated 11-4-2014 for which you said it comes from improperly cleaned hospital instruments. I am very interested in how I would of contracted this bad deadly infection.

  • Dante says:

    Hello ive been diagnose of Serratia SPP…. My doctor prescribed me one week antibiotic but seems is not working. I have UTI when i pee it burns… What should i do is there any other treatment out there to kill this? Can you get this through STD? I had sex multiple woman in a past few months. My doc said its not STD its a bacterial in our body that triggers if your immuned system gets low. But i dont have chills or fever.. PLease advice. thank you.

    • DeadlyMicrobes says:

      The bacteria can be transmitted in many different ways. Please take the advice of your doctor. It sometimes takes quite a while for treatment to work it’s way through stopping the bacteria and then eliminating symptoms. Make sure you get frequent tests. It’s also possible you have two infections – one of serratia and another being the STD. You should always feel comfortable to get a second opinion.

  • Amanda says:

    I recently had a culture biopsy done from an abcess on my thumb and found out it was s. marcescens and some yeast. Im now on 3 months of ciprofloxacin and 3 months of fluconazole. I also have to get a debridement because the serratia has caused osteomyelitis in my thumb. It has taken me 6 mnths and quite a few tests to get to this diagnosis. Not looking forward to this surgery.

  • stephen walters says:


    • DeadlyMicrobes says:

      Hi Steve, There’s no way to tell unless you see a doctor to have tests. And I agree with you – it is worth looking into.

  • Sandra Hatcher says:

    I have a son thats paralyzed, crushed his C six in a diving accident. He keeps a microorganism in his bladder because he has a super pubic cath. He has just been diagnosed for the second time in 2 months with the serratia marcescens bacteria. Do you have any ideas of how I can keep his shower, shower chair and everything in his room as clean as possible ? Would it be possible to tell me what kind of household cleansing products that would help keep this organism down or kill it.

    • DeadlyMicrobes says:

      Hi Sandra, just about any bleach based cleaner would work. I would dry the area completely and then do several cycles of clean-dry-clean. Remember it’s no so much about cleaning solids, but killing microscopic bacteria. The area may look clean but could still be infected. Make After cleaning, consider opening curtains and blinds to allow sunshine to come into his room.

  • Judy Smith says:

    I am 64 years old and I found out in 06 when I got pneumonia and ended up in the hospital and had several including lung biopsy’s that I have Sarcoid disease. It seems like every winter or spring I end up very sick or even in the hospital with a bacterial infection. I have had pneumonia several times caused by a bacteria. It is usually caused by MRSA or Staph. This year I was blessed with an infection that started the 25th of January I ran a fever for three weeks had Bronchitis so of course coughed my head off. I was given 10 day of Levaquin at first then after a few days off of any antibiotic my family Dr. ordered a sputum which showed a growth of 1+WBC, 3+ Gram positive Cocci, Gram Negative Bacillus. or Staph and Serratia Marcescens. I went to ER before I got that sputum report because I was so sick which was no help at all the PA who saw me simply looked at a chest xray they took and never even listened to my chest. His diagnosis was Acute Bronchitis and he gave me a Z pack. The day I was there after the nurse or tech came in and hooked me up to the moniter all the alarms started going off and my vitals where plus ox 85, plus 96 and Bp 116/53. I went home and took the Z pack all the time getting worse. I finnaly got the news from my Dr. what the sputum report said and he ordered 10 days of Bactrum DS. My family Dr. sent this report to my Pulmonologist who called me and said if I wasn’t better aftera couple of days of the Bactrum DS to come back and see him. I ended up back to see him and he added to the Bactrum DS 14 more days of Levaquin and Medrol Pack and wanted me to take 14 days of Clindamyicin but I did not take it because it caused my husband to get Cdiff back in November. I finised all of that they sent off another sputum and it came back with the Staph gone but the Serratia was still there so my Pulmonologist put me on 7 days of Cipro. I took it and waited 5 days and sent off another sputum and I just got a call from my family Dr. yesterday that the Serratia is still there. I think they are thinking it is colonized. They sent me to an infectious disease docter but I really didn’t learn much from her. I am feeling much better although I still get tired really easy. If it is colonized is there any way to get rid of it and how do I find out how I got this nasty bug? I haven’t been in the hospital other than that ER and that PA never even touched me now the nurse did when she hooked me up. I am on O2 at home of the night but I change my cannula’s frequently. I do have a small humidifier in my bedroom to help with my dry eye’s but I also clean it frequently. I only clean it with vinager water until this and I have switched to bleach water. I use distilled water which I thought was good but then I read some where that Serratia was sometimes found in that. I don’t know what to do. I am worried about my family or my dog getting this from me some how and I need to reschedule a surgery to remove a deep skin cancer from my nose. This will be the third time I am having to have this done so they are planing on taking me into OR this time to do a frozen section on it and I am afraid to go back and have it redone afraid I will get this serratia in it. I would appreciate any input on all of this. All together I have had 24 days of Leaquin, a Z pack, 10 days of Bactrim DS and 7 days of Cipro plus the Medrol pack. That should be enough to kill a horse let alone a bug. Can I give this to my dog? THanks Judy

    • DeadlyMicrobes says:

      Hi Judy, It sounds like you’re in good hands with your doctors. We recommend that you also discuss postponing the skin cancer surgery and not make any rash decisions – either way.

      As for why you continue to get infected every year, I would suggest looking at environmental reasons. Clean and dry out any areas of standing water or mildew in your home or your workplace. Considering that it happens in winter or spring I would look to see if you have a humidifier on your furnace. It is common to have water run over a metal mesh which is in the warm air duct from the furnace. The mesh needs to be cleaned or replaced but they’re easy to overlook. You may also want to have a company look through your air ducts. They can do that with a scope that is run from one or two places and see all of the ducts. You may need to have them cleaned and disinfected. Find a reputable firm though – unfortunately duct cleaning is a common scam.
      Good luck and please let us know how you progress.

      • Callie Reynolds says:

        I am seeing this pink film s, marcencens coming out of our treatment plant water where I live. So to blame her home is crazy when it’s coming in the treatment plant water.
        Please revisit the treatment plants in the US for over run of this fungus.

        • DeadlyMicrobes says:

          We’re not blaming anyone. There are certain things to look for … anything with standing or pooling water, is a potential source of bacteria. It’s always good practice to eliminate the most likely potential problems first.

  • jessie says:

    I was just diagnosed having an infection due to serratia marcesen. this is the 3rd time within 1 year of getting this cough. is this catching to my family members? I hope that I am rid off it now, due to the fact that I was put on Levaquin. z pack did not work in the past, neither did prednzonolone

    • DeadlyMicrobes says:

      Hi Jessie, It’s possible that your family members could contract a serratia infection if the source is your home. You should remove any standing water – inside and out and keep clean your countertops, sinks and faucets, and toiletries like razors or shavers. There is something in your environment that is causing you to become infected.

      • THELMA LEMBERG says:


  • Nancy says:

    I am a 62 yr old female that has been suffering from terrible abdominal bloating and gassy feeling, usually occurring mid day til evening. Trying to research and come up with answers, as doctor only want to give me pills, I have blamed it on food allergies. Eliminating/adding….etc, can’t come up with die hard answer there.
    Meanwhile, researching the pink slim that I have in my Kuerig coffee maker and in all my bathroom “wet spots”, toilet, etc, I came up with relating the stomach issue to this Serratcia. Any possibility, in your opinion?

    • DeadlyMicrobes says:

      Hi Nancy, Yes it’s certainly possible and the symptoms make sense too. Serratia is especially likely in areas where water can pool and sit for some time. It can also be difficult to kill the bacteria. Please try drying the areas where the slime is, and clean well with anti-bacterial cleaner. Be careful of using bleach in your Keurig – I’m not sure if it would affect the internals.

      Please keep us updated.

  • Vivian says:

    My white Siberian husky seems healthy but has turned pink on her belly fur , around her collar fur and other areas that got very wet and did not dry due to her double undercoat. She also smells kind of like buteric acid in some spots spots (e.g. vomit smell/ durian fruit smell/ locker room smell) despite being bathed multiple times and blow dried. The smell goes away but comes back as soon as she gets damp. I am thinking this is serratia. Is this possible? How do I get it cultured? Can I just clip some pink fur?

    • DeadlyMicrobes says:

      Hi Vivian, Your diagnosis sounds like it’s accurate but it’s always hard to tell without a sample. We’ve been putting together a bacterial home-test kit and will have a link in the next few weeks. I understand that you probably don’t want to wait that long, so you should consider taking your dog to the vet for diagnosis and testing. They can extract some tissue which will include the serratia bacteria (if present) and use that to test. Thank you for asking and please let us know the results.

      • Tammi says:

        Is there a bacterial home test kit available now? If so would really appreciate you posting the link. Thanks so much and thank you for a very informative site.

        • DeadlyMicrobes says:

          Hi Tammi, We’re not able to make our kit available. We were advised that we could have trouble if the test kit malfunctioned or its results gave false positives. We made this site to help people and don’t have the kind of resources available to defend ourselves if necessary. But we’ll continue to answer questions and update our articles with new content. Thank you.

  • Beth Mendez says:

    Curious what you might suggest, 86 year old femaie – recurring UTI’s – ALS Patient 8 yrs, vent 7 years was doing wonderful prior to this UTI in June. She has had numerous UTI’s over the years due to an indwelling foley. In June, first time this bacteria was identified. “s marcescens” came back in the culture report. Doc thought she had a fistula, believe that has healed up, But We have been playing roller coaster with this bacteria ever since.

    Doc has done imipenin 14 days, – off about 7 days later, clinical symptoms are back again (puss discharge around foley and not lucid. Round 2 – Did Primaxin for 2 weeks. off 7 and discharge and fever remerges. We did 7 days of Levaquin and 10 days of Xyvox most recently (ALL IV) – had the best clinical improvement with that combo. We are now finished and sure enough – 10 days out, fever has started again. Is there a way out with this bug?

    It feels like to me that we just haven’t used it long enough to really get the bug gone.

    Any thought would be wonderful.

    • DeadlyMicrobes says:

      Beth, We strongly recommend you work with your doctor and if you have reason for concern, please get a second opinion. No good doctor on the planet would talk you out of having someone else corroborate or disprove their diagnosis. And please be sure the doctor works in a system that has infectious disease experts on staff. You need an expert to follow the progression/regression of the disease and alter treatment accordingly. You cannot take a bunch of pills and be cured. These microbial diseases don’t work that way.

    • DeadlyMicrobes says:

      If you know a broth or any food contains pathogens, do not consume. In situations where you have no choice, please boil the broth for at least 4 minutes before consuming.

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