UNILATERAL AXILLARY LYMPHADENITIS CAUSED BY PSEUDOMONAS AERUGINOSA- A RARE CASE REPORT

1. Associate Professor, Department of Microbiology, Agartala Government Medical College, Agartala, Tripura, India. 2. Post Graduate Trainee (3 Year), Department of Microbiology, Agartala Government Medical College, Agartala, Tripura, India. 3. Professor & HOD, Department of Microbiology, Agartala Government Medical College, Agartala, Tripura, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 20 June 2020 Final Accepted: 24 July 2020 Published: August 2020


ISSN: 2320-5407
Int. J. Adv. Res. 8(08), 691-694 692 cat on right hand. It was painless and associated with mild fever. A clinical diagnosis of 'cat-scratch disease' (infection caused by Bartonella henselae, a gram negative α 2 proteobacteria) was made and he was started on Tab. Doxycycline 100mg BD for 7 days which is the drug of choice.
Three days following the antimicrobial therapy, patient suddenly developed discharge from the swelling. It was greenish in color and it was associated with fever and pain in the right axillary region.
On General physical examination, patient was of average built, febrile, with stable vitals (HR-96/min, regular; BP-130/80mm Hg). Systemic examination was within normal limits. Local examination revealed a large (approx. 5cm diameter), firm, immobile, tender swelling, 5cm anterior to the right midaxillary line. It was associated with greenish white, non-foul smelling, serosanguinous discharge. There was no other enlarged lymph node in other parts of the body

Diagnostic work up:
Routine investigations revealed high total leukocytecounts (14,000/mm 3 ) with neutrophilic predominance, normal Hb% (11.3 g%) and raised ESR level (24mm/hour). His fasting and post prandial blood glucose levels were within normal limits (102mg/dl and 133mg/dl respectively). His LFT, KFT and lipid profile were within normal limits.
Right axillary USG revealed a large (5.2 x 2.7cm) lymph nodal mass lesion with possible central necrosis.
FNAC from the lymph node was performed but it did not reveal any feature of granulomatous inflammation.
The discharge was collected after careful cleaning of the skin surface and then by a sterile inoculating loop in Department of Microbiology, AGMC and was processed as per standard protocol followed in the Department [5,6] . Gram stain was performed which revealed plenty of pus cells per OIF with Gram Negative Bacilli. Ziehl-Neelsen stain was performed but no Acid-Fast Bacilli were seen.His CBNAAT test was also negative. Discharge was inoculated in Blood agar, MacConkey agar, Nutrient agar plates and incubated at 37 0 C under aerobic conditions. Anaerobic culture was also performed after inoculation in Blood agar plate and Robertson's Cooked Meat Broth incubated at 37 0 C. Discharge was inoculated in Tryptic Soya agar plate supplemented with 5% sheep blood, incubated at 37 0 C under 5-10% CO 2 for 21 days to isolate Bartonella henselae. [7] Fungal culture was also performed by inoculation in Sabouraud Dextrose Agar (SDA) with and without antibiotics, incubated at 37 0 C and 25 0 C After 24 hours of aerobic incubation at 37 0 C, growth of bacterial colonies was observed in Blood agar and MacConkey agar plates. Blood agar showed growth of large, grey, irregular, moist colonies and MacConkey agar showed growth of non-lactose fermenting, large, irregular colonies. Growth in nutrient agar showed presence of diffusible green pigment. Colonies were identified as Pseudomonas aeruginosa through colony morphology, biochemical tests, pigment formation and growth at 42 0 C. [8] No growth was observed in anaerobic culture after 5 693 days of incubation or in Tryptic Soya agar plate after 21 days of incubation. No growth was observed in fungal culture after 21 days of incubation.
Antimicrobial susceptibility test was performed using Kirby-Bauer's disc diffusion method [9] as per CLSI protocol M100 ED30:2020. [10] The strain was susceptible to Piperacillin-Tazobactam (100/10µg), Ceftazidime (30µg), Cefepime (30µg) and Imipenem (10µg) and resistant to Amikacin (30µg) and Levofloxacin (5µg).  Follow up-Patient was started on Inj. Ceftazidime 1gm IV 8 hourly for 7 days. His condition improved but discharge was still present. A second culture was obtained and processed as described which yielded the same organism with similar antimicrobial susceptibility profile. He was started on Inj. Piperacillin-Tazobactam 4.5gm IV 8 hourly for 7 days. His further recovery was uneventful.

Discussion:-
Pseudomonas aeruginosa is an opportunistic pathogen, causing serious infection in patients with weakened immune systems, including life threatening ventilator associated pneumonia (VAP), surgical site and urinary tract infections in patients from Intensive Care Units (ICUs). [11] As per ICMR data, 2019, it is the third most common isolate from clinical samples (12%) following Escherichia coli and Klebsiella pneumoniae and carbapenem resistance was seenin 694 50% of the isolates from ICU, followed by 35% from ward and 20% from OPD which is a matter of grave concern. [12] Lymphadenitisis a novel manifestation of Pseudomonas aeruginosa infection. Bacterial causes of axillary lymphadenitis include cat-scratchdisease, staphylococcal or streptococcalinfections, mycobacterialinfections,tularemia and brucellosis. [3] Only one case of axillary lymphadenitis due to Pseudomonal infectionhave been reported till date (Pinninti SG et al, 2008). [3] Our case has a typical history for Cat scratch disease, but it was ruled out by both microbiological and histopathological examinations. Infection caused by Pseudomonas aeruginosa was confirmed by re-isolation of the organism with similar antimicrobial profile. The patient did not have any apparent predisposing conditions and further tests are now being carried out to rule out any other form of immunocompromised state.