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Year : 2016  |  Volume : 5  |  Issue : 1  |  Page : 64-66

Neonatal sepsis and coagulopathy secondary to congenital transmission of Proteus mirabilis

1 Department of Pediatrics, Brooke Army Medical Center, Fort Sam Houston, TX 78234, USA
2 Department of Pathology, Brooke Army Medical Center, Fort Sam Houston, TX 78234, USA

Date of Web Publication6-Jan-2016

Correspondence Address:
Christopher M Daly
Department of Pediatrics, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2249-4847.165703

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Proteus mirabilis infection is rare in neonates. In this population, the majority of described infections involve the central nervous system (CNS). We describe an unusual case of congenitally acquired P. mirabilis infection in a neonate presenting as sepsis, pancytopenia, and coagulopathy. Providers should consider this organism as a cause of severe illness in the newborn period, even in the absence of CNS involvement.

Keywords: Chorioamnionitis, congenital infection, Gram-negative sepsis, Proteus mirabilis

How to cite this article:
Daly CM, Carr NR, Raj T, Maranich AM. Neonatal sepsis and coagulopathy secondary to congenital transmission of Proteus mirabilis. J Clin Neonatol 2016;5:64-6

How to cite this URL:
Daly CM, Carr NR, Raj T, Maranich AM. Neonatal sepsis and coagulopathy secondary to congenital transmission of Proteus mirabilis. J Clin Neonatol [serial online] 2016 [cited 2020 Jul 15];5:64-6. Available from: http://www.jcnonweb.com/text.asp?2016/5/1/64/165703

  Introduction Top

Proteus mirabilis is a gram-negative bacillus classified in the Enterobacteriaceae family and well-established in the pathogenicity of urinary tract infections (UTIs). The bacteria have many virulence factors including fimbriae with adhesive proteins, urease production and the ability to differentiate into swarm cells that help mediate an invasion. The genus name, Proteus, pays tribute to a Greek God with the ability to constantly change form and thus avoid capture.[1] Although uncommon among neonates, P. mirabilis infection has been associated with sepsis, meningitis and brain abscess formation.

We present a unique case of a premature neonate delivered for maternal chorioamnionitis with a hospital course notable for sepsis, pancytopenia, and coagulopathy secondary to suspected congenital transmission of P. mirabilis based on amniocentesis and placental tissue culture positivity.

  Case Report Top

A 25-year-old G2P1 woman presented to labor and delivery with a complaint of increased pelvic pressure at 27 weeks gestational age. Maternal laboratory evaluation at the time of admission was not concerning. During the course of admission, the woman developed a fever to 100.5° Fahrenheit and had contractions with cervical dilatation. The fetal heart tones were nonreassuring. Amniocentesis showed a low glucose (<2 mg/dL) and Gram-negative rods on Gram-stain. The decision was made to proceed to delivery given concern for intra-amniotic infection and preterm labor.

Upon delivery, the infant was noted to have poor color and minimal respiratory effort. Initial heart rate (HR) was between 60 and 80 beats/min and failed to improve with positive pressure ventilation (PPV), prompting the team to intubate. Despite intubation and increased PPV, bradycardia and hypoxia persisted. Half of a standard dose of surfactant was given in the delivery room with a subsequent increase in HR to 130s and oxygen saturation to >98%.

The infant was admitted to the neonatal Intensive Care Unit where she received more surfactant, underwent umbilical line placement, and was started on empiric treatment with ampicillin and gentamicin. A chest radiograph revealed bilateral patchy alveolar opacities with decreased lung volumes. Initial labs revealed a white blood cell count of 400/µL, hemoglobin of 9.9 g/dL, hematocrit of 29.9%, and platelets of 81,000/µL, in addition to increased prothrombin time and partial thromboplastin time suggestive of coagulopathy and pancytopenia secondary to sepsis. The infant had no signs or symptoms concerning for central nervous system (CNS) involvement and she had a normal head ultrasound. Given the increased risk conferred by her coagulopathy, a lumbar puncture was deferred.

The infant received aggressive treatment to include two packed red blood cell transfusions, a platelet transfusion, fresh frozen plasma and a second dose of Vitamin K within the first 48 hours of life with subsequent resolution of coagulopathy. The infection was attributed to P. mirabilis based upon positive maternal amniotic fluid and placenta cultures. Histologic examination of the placenta demonstrated necrotizing chorioamnionitis [Figure 1] and pan-umbilical vasculitis [Figure 2]. The infant was placed on ampicillin monotherapy, targeting P. mirabilis, for a total of 14 days with clinical improvement and without relapse at time of discharge at 62 days of life (36 weeks corrected gestational age).
Figure 1: Membrane roll demonstrating necrotizing chorioamnionitis. (H and E, ×200)

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Figure 2: Pan-umbilical vasculitis. (H and E, ×240)

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  Discussion Top

P. mirabilis is a Gram-negative, dimorphic, motile bacterium within the family of Enterobacteriaceae. The organism is ubiquitous and can be isolated from soil, water, sewage and the human intestinal tract. P. mirabilis is a well-known cause of UTIs, chronic suppurative otitis media and mastoiditis in childhood, in addition to Gram-negative meningitis in infants. The bacteria have many virulence factors including fimbriae which help mediate adhesion and allow for swarming motility, urease production which produces nitrogen for metabolism and the ability to uptake metals such as iron and zinc.[1],[2] It is these virulence factors that allow this bacterium to evade the immune system and cause both systemic and localized infections.

Overall, Proteus spp. is a relatively uncommon causative agent in neonatal infections. However, the association between P. mirabilis and CNS infections among infants and children has been previously reported in the literature.[3],[4] One particular study by Unhanand et al. reviewed 98 cases of Gram-negative bacterial meningitis among infants and neonates admitted to a Children's Hospital in Texas over a 20 year period. This study found that Proteus spp. was the causative agent in 4% of these cases.[4] Another 13-year longitudinal review in Taiwan attributed P. mirabilis infection to 7.1% of cases of bacterial meningitis among neonates.[5] Additionally, there is a report of a P. mirabilis outbreak that led to bacteremia and meningitis among neonates in a newborn nursery.[6] Lastly, cerebral abscess formation is well-established as a potential complication of P. mirabilis meningitis.[7]

The clinical outcomes associated with P. mirabilis CNS infections are poor. A review by Renier et al. revealed significant morbidity and mortality among neonates who contracted P. mirabilis infections, including death (13%), hydrocephalus (47%) and decreased developmental and intelligence scores (63%).[8] Additionally, among neonatal meningitis cases, in general, there is a higher mortality rate associated with Gram-negative infections than in those infections caused by Gram-positive pathogens.[9]

It is presumed that the infant in our case contracted the infection via vertical transmission during the perinatal period based on amniotic fluid and placental tissue. The diagnosis of severe coagulopathy secondary to sepsis and maternal necrotizing chorioamnionitis makes this case unique and emphasizes the degree of morbidity associated with P. mirabilis infection among neonates. This pathogen should be considered in septic newborns, especially in the setting of maternal chorioamnionitis, even without evidence of cerebral abscess.

  Conclusion Top

We present an unusual case of maternally transmitted P. mirabilis infection in a neonate with a high degree of coagulopathy and pancytopenia. This is a rarely reported clinical presentation of infant infection following maternal chorioamnionitis which presented as sepsis, pancytopenia, and coagulopathy. Although outcomes associated with this pathogen can be poor, our patient improved clinically with aggressive supportive care and standard antibiotic therapy. Proteus mirabilis should be considered as a potential causative agent in severe postnatal neonatal infections.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Donnenberg MS. Enterobacteriaceae. In: Mandell GL, Bennett JE, Dolin R, editors. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, PA: Elsevier, Churchill Livingstone; 2005. p. 2567-86.  Back to cited text no. 1
Armbruster CE, Mobley HL. Merging mythology and morphology: The multifaceted lifestyle of Proteus mirabilis. Nat Rev Microbiol 2012;10:743-54.  Back to cited text no. 2
Phan H, Lehman D. Cerebral abscess complicating Proteus mirabilis meningitis in a newborn infant. J Child Neurol 2012;27:405-7.  Back to cited text no. 3
Unhanand M, Mustafa MM, McCracken GH Jr, Nelson JD. Gram-negative enteric bacillary meningitis: A twenty-one-year experience. J Pediatr 1993;122:15-21.  Back to cited text no. 4
Chang Chien HY, Chiu NC, Li WC, Huang FY. Characteristics of neonatal bacterial meningitis in a teaching hospital in Taiwan from 1984-1997. J Microbiol Immunol Infect 2000;33:100-4.  Back to cited text no. 5
Sung L, Macdonald NE, Hutchison JS. Concurrent neonatal Proteus mirabilis infection in dizygotic twins. Can J Infect Dis 1999;10:156-8.  Back to cited text no. 6
Smith ML, Mellor D. Proteus mirabilis meningitis and cerebral abscess in the newborn period. Arch Dis Child 1980;55:308-10.  Back to cited text no. 7
Renier D, Flandin C, Hirsch E, Hirsch JF. Brain abscesses in neonates. A study of 30 cases. J Neurosurg 1988;69:877-82.  Back to cited text no. 8
Franco SM, Cornelius VE, Andrews BF. Long-term outcome of neonatal meningitis. Am J Dis Child 1992;146:567-71.  Back to cited text no. 9


  [Figure 1], [Figure 2]


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