Urinary tract infection with Pasteurella multocida in a patient with cat exposure and abnormal urinary tract physiology: Case report and literature review

Abstract

Pasteurella multocida is a gram-negative organism that commonly colonizes the mouth of cats and dogs, and is known to cause infection in humans associated with animal bites or scratches. Sites of infection other than skin and soft tissue are rare, but have been reported in patients with specific risk factors including anatomical abnormalities or immunosuppression. Herein, we report a case of a symptomatic urinary tract infection caused by P. multocida in a 59 year old female who presented to the hospital with complaints of systemic symptoms including malaise, rigors, and chills, as well as thick, malodorous urine. The patient self-catheterized multiple times daily due to urostomy with Kock pouch. Treatment with piperacillin/tazobactam followed by amoxicillin resulted in resolution of the infection.

Introduction

Pasteuerella multocida is a small, gram-negative coccobacillus that is known to be part of the normal oral flora of cats and dogs [1]. Of the Pasteurella species, cats and dogs have the highest carriage rate of P. multocida, with 70 to 90 percent in cats and 20 to 50 percent in dogs [2]. In humans, P. multocida is most commonly associated with skin and soft tissue infections from cat bites or scratches. The Pasteurella species as a whole are usually susceptible to penicillin [1]. Herein, we report a case of a urinary tract infection (UTI) caused by Pasteurella multocida.

Case report

A 59-year-old female presented to the emergency department with complaints of general malaise, rigors, and chills. She also complained of thick, malodorous urine on self-catheterization. Her past medical history was significant for cervical cancer status post colostomy and urostomy with Kock pouch (continent ileostomy), nephrolithiasis, and UTIs. The patient reported using an 18 french coude disposable catheter on herself four to six times per day. Upon physical examination, she was found to be afebrile with a temperature of 37.5 °C, a blood pressure of 79/61 mmHg, respiratory rate of 18, and an oxygen saturation of 96% on room air. Complete blood count revealed leukocytosis with white blood cells of 23.5 × 10³ cells/microL. Red blood cells, hemoglobin and hematocrit were all within normal limits. A urinalysis was performed and was positive for nitrite, 3+ leukocyte esterase, >100/hpf white blood cells, many bacteria, moderate yeast, and few epithelial cells. Blood and urine cultures were collected in the emergency department prior to initiation of antibacterials. Based on her physical presentation, urinalysis results, and past medical history, she was diagnosed with a complicated UTI and admitted as an inpatient for further treatment.

In the emergency department, antibacterial therapy was started with 3.375 g of piperacillin/tazobactam. On admission, renally dose-adjusted piperacillin/tazobactam (2.25 g IV q6 h) was continued for empirical treatment of the complicated UTI. Three days later, the urine culture was finalized with greater than 100,000 CFU/mL Pasteurella multocida, which was susceptible to all antimicrobial agents tested (amikacin, ampicillin, ampicillin/sulbactam, aztreonam, cefazolin, ceftriaxone, ciprofloxacin, gentamicin, meropenem, nitrofurantoin, piperacillin/tazobactam, tobramycin, trimethoprim/sulfamethoxazole). The antimicrobial regimen was streamlined to oral amoxicillin 500 mg three times daily. At time of discharge three days later, her white blood cell count had normalized to 6.4 × 10³ cells/microL and her systemic symptoms had improved. The patient was given a prescription upon discharge for amoxicillin to complete a ten day total course.

Discussion

Pasteurella multocida is a pathogen that colonizes the mouth of cats and dogs, and as such is primarily associated with skin and soft tissue infections in humans secondary to animal bites [1]. Rarely, P. multocida has been reported to be associated with other sites of infections, including pneumonia, upper respiratory tract infections, endocarditis, meningitis and UTIs [3]. A literature review of UTIs caused by P. multocitda revealed nine published cases with patient-specific information, summarized in Table 1 [4], [5], [6], [7], [8], [9], [10], [11]. There are also several earlier papers which mentioned the presence of urinary tract infection with P. multocida but did not provide details about the patient case or outcomes, and as such these are not included in our review [3], [12]. In six of the nine published case reports, preexisting urinary pathology was present, predisposing the patients to UTIs. Animial exposure was reported in six of the nine cases as well, suggesting a potential source of the P. multocida organism.

Table 1.

Reported cases of Pasteurella multocida urinary tract infection.

Author (Year)	Age	Gender	Predisposing Factor(s)	Known Animal Exposure	Treatment	Treatment Successful
Dixon [4] (1967)	62	Female	Bladder carcinoma	Yes 1 pet cat	1.5 g IV ampicillin, then 500 mg ampicillin q8 h for 10 days	Yes
Komorowski [5] (1974)	63	Male	Pelvic radiotherapy, prostate adenocarcinoma, TURP	Unknown	600,000 units of penicillin IM BID for 7 days	Yes
	51	Male	Uncontrolled diabetes	Unknown	600,000 units of penicillin IM BID. Unknown duration	Yes
Bailah [6] (1977)	15	Male	Ileal loop, self-catheterization	Yes 2 pet cats, pet rabbit	70 mg gentamicin IM once	Yes
Conley [7] (1983)	77	Female	Advanced age	No	Trimethoprim/sulfamethoxazole DS BID for 10 days	Yes
Warren [8] (1984)	26	Female	Ileovaginal fistula, repaired by ileal bypass	Yes Pet dogs/cats, uninfected dog bite 1 year prior	Trimethoprim/sulfamethoxazole Unknown duration.	Yes
Mann [9] (1987)	31	Female	Prior pyelonephritis	Yes 1 pet dog	Ampicillin 500 mg QID for 14 days Amikacin 500 mg IV q6 h, cephalothin 1 g q6 h for 24 h. Cephradine 500 mg PO for 14 days total.	Yes
Liu [10] (2003)	56	Female	Indiana pouch with urinary diversion, catheterization	Yes 2 pet cats in household	Unknown	Unknown
Cortez [11] (2007)	13	Male	ESRD, self-catheterization	Yes 1 pet cat	Ampicillin/sulbactam, amoxicillin/clavulanate 14 days total.	Yes

BID = twice daily, QID = four times daily, PO = by mouth, IM = intramuscular, IV = intravenous, ESRD = end stage renal disease, TURP = transurethreal resection.

In all reported cases where antibacterial therapy was discussed (eight of nine), successful treatment was achieved, with the most common therapy utilized being penicillins, aminoglycosides, and trimethoprim/sulfamehoxazole. Although the organism is generally susceptible to ampicillin, the preferred treatment for most infections due to P. multocida is amoxicillin/clavulanate or ampicillin/sulbactam because they are usually associated with animal bites and therefore anaerobic coverage is necessary. However, in the case of UTI due to P. multocitda, anaerobic coverage is likely not warranted as most infections of the urinary tract are monomicrobial.

In the present case, the patient had several predisposing factors, including a history of cervical cancer which led to a urostomy with Kock pouch placement in 1989. Because of this urinary tract pathology, the patient self catheterized multiple times daily, which increases her risk of urinary tract infections. In fact, the patient had a history of recurrent urinary tract infection, including some caused by multidrug resistant bacteria such as extended-spectrum beta-lactamase (ESBL) producing Escherichia coli. Upon identification of P. multocida in our patient’s urine culture, futher questioning regarding pets in the home revealed that she had two pet cats in her apartment, and an additional four cats live in the apartment above her with her son, with free passage between the apartments for the cats. She did, however, report good hand hygiene prior to catheter insertion, and had no known prior infection related to exposure to these animals. The cats were not declawed, however the patient denied any history of recent bites or scratches from any of the cats. Upon initaiton of therapy active against P. multocida, our patient improved quickly and was able to be discharged home to complete her treatment course. She has had no known recurrences of P. multocida infection and reported no adverse sequelae from her urinary tract infection.

This case highlights the importace of taking a detailed patient history, including questions regarding animal exposure, in order to determine the source of the infection. Cats are a common reservoir of P. multoicda so the infection described is likely due to contact with the animals. Knoweldge of the source of the pathogen can help guide clinicians to counsel patients on ways to prevent future infections. In the case of P. multocida infection, a household with multiple cats is likely to be colonized with the organism so complete avoidance is likely not feasible. Specific measures, however, may be useful in preventing future infections. In this case, the patient could be instructed to isolate catheter insertion to a room of the house that the animals are not able to freely travel, such as a bathroom with the door regularly kept closed. The importance of hand washing and sterile insertion technique should also be emphasized.

In conclusion, P. multocida is a rare cause of urinary tract infection but it can occasionally be found in patients with anatomic abnormalities of the urinary tract who have esposure to animals, especially cats. In our case, urinary tract infection with P. multocida was likely due to exposure to cats in a patient predisposed to infection due to presence of urostomy with Kock pouch requiring self-catheterization multiple times daily.

Conflicts of interest statement

The authors declare that they have no conflict of interest. The patient provided written consent to allow us to publish this de-identified case report.