CONTACT : HIND ZRIKEM dr.hind.zrikem@gmail.com © International Journal of Applied Biology 21 Abstract Human diseases due to A. paraphrophilus aren’t usual. The following case report describes the first isolated case of A. paraphrophilus brain abscess in our laboratory. A 9-year-old boy presented to pediatric emergencies for frontal headache, vomiting, blurred vision and left hemiparesis. Radiological diagnosis consists with a frontal abscess. Gram staining of purulent samples showed abundant neutrophils with gram negative bacilli. Culture was made on blood agar, chocolate agar, Chapman’s agar and incubated in 5% CO2 at 37°C for 24 hours. Positive culture was detected only on chocolate agar. It was monomicrobial with small yellowish non-hemolytic colonies. Gram stain of colonies showed pleomorphic gram-negative coccobacilli. The strain required V factor for growth. The isolated strain was sensitive to all antibiotics tested. The interest of this case is that it shows the emergence of A. paraphrophilus as a causative agent of brain abscesses on pediatric population without associated congenital heart disease. It may also help identifying risk factors of these infections and how to prevent them. ISSN : 2580-2410 eISSN : 2580-2119 Haemophilus paraphrophilus brain abscess in a 9-year-old boy: Case report and literature review Hind Zrikem, Loubna Ait Said, & Kawtar Zahlane Microbiology department, University Hospital Mohammed VI, Marrakech, Morocco Introduction H. aphrophilus and H. paraphrophilus are now combined as the same species: Aggregatibacter aphrophilus, with the V-factor dependence of H. paraphrophilus being considered as a variable phenotypic characteristic [1]. A. aphrophilus belongs to the HACEK group, fastidious gram-negative bacilli that are found in the human upper respiratory and genitourinary tracts [1]. A. aphrophilus may cause brain abscess and infective endocarditis and has been isolated from various other body sites including peritoneum, pleura, wound and bone [2]. Case Report A 9-year-old boy was admitted to pediatric emergencies for frontal headache not relieved with painkillers, vomiting and blurred vision. He had no obvious associated conditions except a sinusitis that took place two weeks ago. On admission, he was afebrile with a stable hemodynamic state. Neurological examination showed a Glasgow coma scale OPEN ACCESS International Journal of Applied Biology Keyword Child, Aggregatibacter paraphrophilus, Sinusitis, Brain abscess. Article History Received 25 January 2020 Accepted 14 June 2020 International Journal of Applied Biology is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Applied Biology, 4(1), 2020 22 score of 13, a supple neck and left hemiparesis. The remaining physical examination was normal. CT with contrast demonstrates a ring-enhancing lesion along with midline shift to the left. Drainage of the abscess was achieved and empiric parenteral antibiotic therapy was initiated with metronidazole (10mg/kg/8h), and ceftriaxone (100mg/kg/j). Other investigations were carried out: ultrasound of liver, chest X-ray and dental examination. These were all negative. Blood tests showed leukocytes 14 x 103/ uL with 9,8 x 103/uL neutrophils, hemoglobin 12g/dL and C-reactive protein 2,8 mg/L. Gram staining of purulent samples showed abundant neutrophils with gram negative bacilli. A small volume of pus was inoculated onto blood agar, chocolate agar, Chapman’s agar and incubated in 5% CO2 at 37°C for 24 hours. Positive culture was detected only on chocolate agar. It was monomicrobial with small yellowish non-hemolytic colonies (figure 1). Gram stain of colonies showed pleomorphic gram-negative coccobacilli. The strain required V, but not X factor for growth, it was oxidase positive and catalase negative. Late identification by API NH system revealed Haemophilus paraphrophilus (Figure 3). Antimicrobial susceptibility was detected by the disk diffusion test using an inoculum of 0, 5 McFarland on M-H base agar supplemented by 5% horse blood and 20mg/L β-NAD. The isolates were susceptible to all antibiotics tested according to EUCAST breakpo int standards (Figure 2). Normalization of WBC counts was obtained by the 10th postoperative day. After six weeks of intravenous antibiotic therapy, CT scan control showed diminished lesion and neurological manifestations disappeared. Figure 1: Culture on chocolate agar International Journal of Applied Biology, 4(1), 2020 23 Figure 2: Antimicrobial susceptibility Figure 3: API NH identification of H. paraphrophilus Discussion Brain abscess is a rare disease in childhood requiring prompt medical and/or surgical treatment [3]. To our knowledge this is the third case report of A. paraphrophilus brain abscess in a child without underlying heart disease. Bacteria reach the brain through contiguous spread, hematogenous dissemination from a distant focus or through a head trauma (penetrating injury, post-neurosurgery) [4]. Congenital heart disease is the most common underlying condition, and the most common preceding infection is sinusitis [3]. We assume that in the case of our patient, the brain abscess was due to a contiguous spread from the sinusitis that took place 2 weeks earlier. The most frequently isolated microorganisms from brain abscesses in pediatric population are Viridans streptococci, Staphylococcus aureus and Enterobacteriaceae [5]. A. paraphrophilus has emerged as an important cause of brain abscesses [6]. A. paraphrophilus is a small, pleomorphic Gram-negative coccobacilli, it’s slow growing requires enriched culture media and increased carbon dioxide tension [7]. Non motile, facultatively anaerobic with no dependence to X factor but V factor is required for growth [2]. Colonies on chocolate agar are granular, yellowish and opaque [2]. Glucose is fermented, ONPG is hydrolyzed and oxidase is positive [2]. Phenotypic characteristics differentiating A. paraphrophilus from other HACEK group species are shown in Table 1. Fortunately, A. paraphrophilus is sensitive to a wide range of antibiotics [8]. Production of International Journal of Applied Biology, 4(1), 2020 24 beta-lactamase should be tested, while third-generation cephalosporins should be considered drug of choice [9]. Ciprofloxacin and the newer fluoroquinolones have potent activity against A. paraphrophilus, and can be used as alternatives for penicillin allergic individuals, and for those infected with strains resistant to cephalosporins [10]. Our isolated strain was susceptible to all antibiotics tested according to the EUCAST breakpoint standards [11]. Table 1. Phenotypic characteristics differentiating A. paraphrophilus from other HACEK group species [2][6] X V CO2 CAT OX NIT ODC LDC ONPG IND GLU LAC SAC A. aphrophilus - + + - + + - - + - + + + A.paraphrophilus - - + - - + - - + - + + + A. actinomycetemcomitans - - + + - + - - - - + - - Eikenella corrodens - - + - + + + + - - - - - Cardiobacterium hominis - - + - + - - - - + + - + Kingella kingae - - + - + - - - - - + - - Haemophilus influenza + + - + + + v v - v + - - Haemophilus parainfluenzae - + - v + + v - v v + - + X: V-factor-dependence; V: V-factor-dependence; CO2: capnophile; CAT: catalase; OX: oxidase; NIT: nitrate; ODC: ornithine decarboxylase; LDC: Lysine decarboxylase; IND: Indole; GLU: Glucose; LAC: Lactose; SAC: saccharose; v: variable The literature review since 1984 showed only 10 previously reported cases of A. paraphrophilus brain abscess (Table 2). Two of the 10 cases are children (20%) and six are males (60%). 30% have underlying congenital heart disease while no predisposing factor was identified in two cases. Therapy is based on antibiotics combined with surgical drainage in 80% of cases. The mortality rate is 20%. Table 2. Reported cases of A. paraphrophilus brain abscesses Case no. date [R] Age (y) / gender Predisposing factors Therapy Outcome 1. 1984 [12] 49 / F None Antibiotics (cefotaxime, metronidazole) Death 2. 1985 [13] 26 / F Congenital heart disease Antibiotics (Ampicillin, Gentamicin) Death 3. 1987 [14] 47 / M Poor dentition Surgical + antibiotics (ampicillin, metronidazole) Recovery 4. 1988 [15] 51 / M Dental manipulation Surgical + antibiotics (Ampicillin, ceftriaxone) Recovery 5. 1990 [16] 43 / M Congenital heart disease Tooth extraction Surgical + antibiotics (ciprofloxacin, metronidazole) Recovery 6. 1996 [17] 66 / F Toothache Surgical + antibiotics (Penicillin G, metronidazole) Recovery 7. 1998 [18] 42 / M none Surgical + antibiotics (cefotaxime, ciprofloxacin) Recovery 8. 2008 [8] 3 / M Otitis media Surgical + antibiotics (3rd generation cephalosporins, metronidazole) Recovery International Journal of Applied Biology, 4(1), 2020 25 9. 2010 [19] 53 / M Congenital heart disease Dental filling ingestion Surgical + antibiotics (meropenem, metronidazole) Recovery 10. 2013 [20] 6 / F Dental extraction Surgical + antibiotics (ceftriaxone, metronidazole) Recovery 11. 2019 (Present case) 9 / M Sinusitis Surgical + antibiotics (ceftriaxone, metronidazole) Recovery R = Reference; M= male; F= female Conclusions A. paraphrophilus is emerging as a causative agent of brain abscesses in pediatric population. Prevention is therefore crucial and involves good dental hygiene and the treatment of any ENT infection. References [1] W. M. Janda. 2013. Update on the HACEK group of fastidious gram-negative bacilli, Part I. Clin. Microbiol. Newsl. 35(11): 87–92. [2] N. Nørskov-Lauritsen and M. Kilian. 2006. Reclassification of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Haemophilus paraphrophilus and Haemophilus segnis as Aggregatibacter actinomycetemcomitans gen. nov., comb. nov., Aggregatibacter aphrophilus comb. nov. and Aggregatibacter. Int. J. Syst. Evol. Microbiol. 56(9): 2135–2146. [3] Z. Sahbudak Bal et al. 2018. Brain Abscess in Children: A Rare but Serious Infection. Clin. Pediatr. (Phila). 57(5): 574–579. [4] I. Brook. 2017. Microbiology and treatment of brain abscess. J. Clin. Neurosci. 38: 8– 12. [5] M. C. Brouwer et al. 2014. Clinical characteristics and outcome of brain abscess : Systematic review and meta-analysis. Neurology. 82(9): 806–813. [6] N. Nørskov-Lauritsen. 2014. Classification, identification, and clinical significance of Haemophilus and Aggregatibacter species with host specificity for humans. Clin. Microbiol. 27(2): 214–240. [7] F. J. Cooke and M. P. E. Slack. 2016. Gram-Negative Coccobacilli, Fourth Edi. Elsevier Ltd. [8] J. Hoefele et al. 2008. Haemophilus paraphrophilus, a rare cause of intracerebral abscess in children. Eur. J. Pediatr. 167(6): 629–632. [9] A. Wanger et al. 2017. Overview of Bacteria. [10] S. Maraki et al. 2016. Aggregatibacter aphrophilus brain abscess secondary to primary tooth extraction: Case report and literature review. J. Microbiol. Immunol. Infect. 49(1): 119–122. [11] V. Janvier et al. 2019. Comité de l’antibiogramme de la Société Française de Microbiologie Recommandations. France. International Journal of Applied Biology, 4(1), 2020 26 [12] M. Habib et al. 1984. Metastatic Cerebral Abscesses due to Hemophilus paraphrophilus. Arch. Neurol. 41(12): 1290–1291. [13] K. T. Jensen and T. Højbjerg. 1985. Meningitis and brain abscess due to Haemophilus paraphrophilus. Eur. J. Clin. Microbiol. 4(4): 419–421. [14] C. J. Papasian et al. Haemophilus paraphrophilus brain abscess. 1987. Diagn. Microbiol. Infect. Dis. 7(3): 205–209. [15] A. J. Pajeau et al. 1988. Haemophilus paraphrophilus Frontal Lobe Abscess: Case Report. Neurosurgery. 23(5): 643–645. [16] J. P. Visvanathan K. 1991. Ciprofloxacin treatment of Haemophilus paraphrophilus brain abscess. J Infect. 22(3): 306–307. [17] A. J. H. Simpson et al. 1996. Polymicrobial brain abscess involving Haemophilus paraphrophilus and Actinomyces odontolyticus. Postgrad. Med. J. 72(847) : 297–298. [18] A. J. Hart et al. 1998. Haemophilus paraphrophilus; a rare cause of intracranial abscess. J. Infect. 37(1) : 75–76. [19] A. S. et al. 2010. Liver and brain abscess caused by Aggregatibacter paraphrophilus in association with a large patent foramen ovale: A case report. J. Med. Case Rep. 4(1) : 2–5. [20] D. A. D.-S. Dra. María Eugenia Vázquez-Toledo, Dr. René Farfán-Quiroz. 2013. Absceso cerebral por Haemophilus paraphrophilus posterior a tratamiento dental en una niña. Informe de un caso. Acta Pediatr Mex. 34(1) : 33–38.