LETTERS TO THE EDITOR

www.elsevierhealth.com/journals/jinf

Journal of Infection (2012) 65, 573e592

Aeromonas genitourinary tract infection

Dear Editor,

We read with great interest the recent review article byParker et al who described the clinical and microbiologicalcharacteristics of Aeromonas spp infections.1 In the review,gastrointestinal tract is the most common site of Aeromo-nas spp. infection, but Aeromonas spp. is also involved inextra-intestinal infections, including bacteremia, pneumo-nia, empyema, necrotizing fasciitis, arthritis, endocarditis,cholangitis, meningitis, skin and soft tissue infection.1 Gen-itourinary tract infections caused by Aeromonas spp. hasbeen less frequently described, although such an associa-tion has been noted in case reports and small series.2e7 Bet-ter understanding of the clinical characteristics ofgenitourinary infections caused by this pathogen is needed,therefore, the aim of our study was to investigate the clin-ical manifestations, microbiological characteristics, re-sponse to treatment, and outcome.

This study was conducted at Chi Mei Medical Center,Liouying branch, a 900-bed tertiary care center in southernTaiwan. From the computerized database of the bacteriol-ogy laboratory from July 2004 to December 2011, patientswhose cultures yielded Aeromonas species were identified.The clinical charts of all patients with urinary tract infec-tion caused by Aeromonas species included in this studywere retrospectively reviewed. Information regarding age,gender, underlying immunocompromising conditions includ-ing history of immunosuppressant drug use, diabetes melli-tus, liver cirrhosis, end stage renal disease, and malignancywere collected.

During the study period, a total of 20 clinical isolates wereisolated from genitourinary specimen form 19 patients. Onepatient had concomitant Aeromonas caviae and Aeromonasveronii urinary tract infection at the same time. Aeromonashydrophila was the most common species isolates (n Z 12)in 12 patients, followed by A. caviae (n Z 6) in 6 patients.In addition, each one strain of Aeromonas veronii biovar so-bria and A. veronii was isolated from each one patient. Theantibiotic susceptibilities for all Aeromonas spp. isolateswere various according to different Aeromonas species, andall of the data were summarized in Table 1. Overall, all ofthe clinical isolates were susceptible to amikacin, and imipe-nem had good activity against 90% of isolates. In contrast, allof the isolates were resistant to ampicillin and cefazolin.

The clinical characteristics of 19 patients with Aeromo-nas urinary tract infections are summarized in Table 2.Women comprised 11 of 19 patients (57.9%), and the ageranged from 5 to 88 years. More than half of patientswere elderly with age > 65 years, and there was one childwith age of 5 years. Active cancer was the most commonunderlying disease, followed by liver cirrhosis and diabetesmellitus. Five patients had received immunosuppressantand three patients had genitourinary tract stone. Abouthalf of patients were classified as immunocompromised sta-tus, which was defined as the patient had any one of thefollowing conditions, including conditions including historyof immunosuppressant drug use, diabetes mellitus, livercirrhosis, end stage renal disease, and malignancy. Nine(47.4%) patients had leukocytosis and six (31.6%) patientshad abnormal liver function. C-reactive protein was ele-vated in 17 (89.4%) patients. Three (15.8%) of 19 episodesof Aeromonas infection were classified as nosocomial infec-tion. All of the patients’ conditions response to antibioticwell and had clinical cure of the infections.

Despite the number of case in this study is limited due tothe rare occurrence of Aeromonas species genitourinarytract infections, the present work, to our knowledge, isthe largest series focus on the clinical characteristics of pa-tients with this uncommon clinical entity. In this study, wehave several significant findings. In the English-language ar-ticles, previous reported cases about Aeromonas species re-lated urinary tract infection were caused by A. hydrophila,A. veronii biotype sobria, Aeromonas popoffii, A. caviae,Aeromonas schubertii,2e6 and Mandal et al showed thatA. caviae was the most common species which caused uri-nary tract infection in four patients in their series of 7cases.2 In contrast, A. hydrophila causes more than halfof the infections in this series. Moreover, it is the firsttime to report that mixed genitourinary infection causedby A. caviae and A. veronii at the same time.

Aeromonas infections has been found to developed in pa-tientswith underlying conditions, such as cancer and receivingimmunosuppressive agents.8,9 In this study, there is no excep-tion that about half of caseswere classified in immunocompro-mised status, including cancer, liver cirrhosis, diabetesmellitus, autoimmune disorders, renal failure and receivingimmunosuppressant. However, more than half of episodes de-veloped in immunocompetent patients in the present work.Therefore, clinicians should be keep in mind that althoughAeromonas infections frequently occur in immunocompro-mised patients, genitourinary tract infection caused by Aero-monas spp. can even develop in healthy subjects.

Table 1 Antibiotic susceptible rates of four species of Aeromonade.

Antibiotic susceptible rate (%)

A. hydrophila(n Z 12)

A. caviae(n Z 6)

A. veronii biovarsobria (n Z 1)

A. veronii(n Z 1)

Ampicillin 0.0 0.0 0.0 0.0Ampicillin-sulbactam 0.0 0.0 100.0 0.0Piperacillin-tazobactam 58.33 50.0 100.0 100.0Cefazolin 0.0 0.0 0.0 0.0Cefuroxime 75.0 16.7 0.0 0.0Ceftazidime 83.3 66.7 100.0 0.0Cefepime 83.3 66.7 100.0 100.0Imipenem 83.3 100.0 100.0 100.0Gentamicin 83.3 50.0 100.0 100.0Amikacin 100.0 100.0 100.0 100.0Ciprofloxacin 75.0 66.7 100.0 100.0Trimethoprim-sulfamethoxazole 50.0 66.7 100.0 100.0

574 Letters to the Editor

In this study, three of 19 episodes were classified asnosocomial. The association between Aeromonas speciesand nosocomial infection has been described in previous re-port.9,10 Although the source of infection in nosocomialcases remains unknown, it suggests that Aeromonas spp.should be considered as one of nosocomial pathogens.

The outcomes of the 19 patients with Aeromonasrelated urinary tract infection are favorable in thepresent work. This finding is consistent with previous

Table 2 Clinical manifestations of 19 patients with Aero-monad related urinary tract infection.

No (%) ofpatients (n Z 19)

Age 60.0 � 25.7Female, n (%) 11 (57.9)Underlying diseaseActive cancer 5 (26.3)Liver cirrhosis 4 (21.1)Diabetes mellitus 3 (15.8)Hepatitis B 3 (15.8)Hepatitis C 1 (5.3)End-stage renal disease 1 (5.3)Renal stone 3 (15.8)Receiving immunosuppressant 5 (26.3)Autoimmune disease 1 (5.3)

Immunocompromised status 9 (47.4)Use of catheter 9 (69.2)Percutaneous nephrostomy 2 (10.5)Foley catheter 1 (5.3)

Laboratory findingsWhite blood cell (cell/ul) 11400 � 5154AST(IU/l) 45 � 21.4ALT(IU/l) 40 � 24Creatinine (mg/dl) 1.0 � 0.57C-reactive protein (mg/L) 60 � 54.9Urinary analysis

White blood cell (/HPF) 52 � 54Red blood cell (/HPF) 16 � 27Bacturia 16 (84.2%)

reported cases3e6 that Aeromonas related urinary tract in-fection resolved with antimicrobial therapy. Aeromonasspp. may be a relative low-virulence microorganism as anuropathogen.

The antibiotic susceptibility pattern of clinical isolateswere similar to previous reports.1 All of them were resistantto ampicillin and first-generation cephalosporin, however,amikacin and imipenem still remains good in vitro activityagainst these clinical isolates. Additionally, more than75% of Aeromonas isolates were susceptible to ciprofloxa-cin, gentamicin, and 3rd or 4th generation cephalosporin.Therefore, fluoroquinolones, at least 3rd generation cepha-losporin, or aminoglycosides should be suggested as the an-tibiotic treatment of choice in this clinical setting ofAeromonas urinary tract infection.

In conclusion, Aeromonads can rarely cause genitouri-nary tract infection in both immunocompromised andimmunocompetent patients. Most of the clinical isolatesare susceptible to fluoroquinolones, aminoglycosides, andat least 3rd generation cephalosporin, and the clinicaloutcomes of this clinical entity are favorable.

Transparency declaration

No conflicts of interest to declare.

References

1. Parker JL, Shaw JG. Aeromonas spp. clinical microbiology anddisease. J Infect 2011;62:109e18.

2. Mandal J, Dhodapkar R, Acharya NS, Sastry A, Parija SC. Urinarytract infection due to Aeromonas spp., a lesser known causa-tive bacterium. J Infect Dev Ctries 2010;4:679e81.

3. Al-Benwan K, Abbott S, Janda JM, Huys G. Albert MJ.Cystitiscaused by Aeromonas caviae. J Clin Microbiol 2007;45:2348e50.

4. Hsueh PR, Teng LJ, Lee LN, Yang PC, Chen YC, Ho SW, et al. In-dwelling device-related and recurrent infections due to Aero-monas species. Clin Infect Dis 1998;26:651e8.

5. Bartolome RM, Andreau A, Xercavins M, Elcuaz R, Salcedo S.Urinary tract infection by Aeromonas hydrophila in a neonate.Infection 1989;17:172e3.

The patient was treated ten days before with amoxicillin1 g orally b.i.d. for 6 days for a GAS tonsillitis (positive re-action for rapid streptococcal antigen test). At admission,she presented only ocular symptoms (Fig. 1, day 0): severeloss in visual acuity (20/63 in the right eye and 20/200 inthe left eye) and bilateral, intense, diffuse sclera rednesswith focal chemosis, but no anterior uveitis. Examinationfindings of the vitreous were normal. Fundus examinationshowed bilateral annular choroidal detachment. Intraocu-lar pressure was 30 mmHg in both eyes. B-scan ultrasonog-raphy revealed bilateral increased thickness of theposterior ocular coats of both eyes. Brain CT-scan with con-trast showed no intra-parenchymal abnormality. Laboratoryinvestigations demonstrated ESR 60 mm/h, CRP 120 mg/L,a leukocyte count of 15 � 109/L and an antistreptodornasetiter of 400 (normal < 200). Serum antibodies to syphilis,Borrelia, HIV, hepatitis B and C were all negative. Serumangiotensin-converting enzyme, rheumatoid factor dosage,and urine analysis function tests were within the normalrange. The anti nuclear antibody test was positive ata low titer (1/160), without specificity: anti-Sm, anti-SSA,anti-RO 52, anti-SSB, Scl-70 antibodies, anti-RNP, anti-JO1and anti-ribosomal tests were negative. Anti-CCP andanti-neutrophil cytoplasmic antibodies were negative.Pending the results of bacteriological and immunologicaltests, the patient received penicillin G (5 M IU every 6 hIV) during 3 days, followed by oral treatment with amoxicil-lin (1 g b.i.d.) for 2 days. After 1 day, symptoms had wors-ened and the patient was treated, with 250 mg of IVmethylprednisolone o.d for 3 days. After the first bolus,the patient stated that she became able to discriminateshape and color. After 3 days, the patient described a totalresolution of her ocular pain and was able to read the news-paper headlines (Day 4, Fig. 1). The IV steroid treatmentwas replaced with 50 mg/day of oral prednisolone, tapered

Letters to the Editor 575

6. HuaHT, BolletC,Tercian S,DrancourtM, Raoult D.Aeromonaspo-poffii urinary tract infection. J Clin Microbiol 2004;42:5427e8.

7. Ojeda-Vargas M, Gonz�alez-Fern�andez MA, Alfonso-Rodr�ıguez O,Monz�on-Moreno C. Urinary tract infection caused by bacteriaof the genus Aeromonas. Enferm Infecc Microbiol Clin 2005;23:181e2.

8. Janda JM, Abbott SL. Evolving concepts regarding the genusAeromonas: an expending panorama of species, diseases pre-sentations, and unanswered questions. Clin Infect Dis 1998;27:332e44.

9. Ko WC, Chuang YC. Aeromonas bacteremia: review of 59 epi-sodes. Clin Infect Dis 1995;20:1298e304.

10. Ko WC, Lee HC, Chuang YC, Liu CC, Wu JJ. Clinical fea-tures and therapeutic implications of 104 episodes ofmonomicrobial Aeromonas bacteraemia. J Infect 2000;40:267e73.

Chien-Ming ChaoDepartment of Intensive Care Medicine,

Chi Mei Medical Center, Liouying, Tainan, Taiwan

Shiow-Jen GauDepartment of Laboratory Medicine,

Chi Mei Medical Center, Liouying, Tainan, Taiwan

Chih-Cheng Lai*Department of Intensive Care Medicine,

Chi Mei Medical Center, Liouying, Tainan, TaiwanE-mail address: dtmed141@gmail.com

*Corresponding author.

Accepted 24 June 2012

ª 2012 The British Infection Association. Published by Elsevier Ltd.All rights reserved.

Post-streptococcal scleritis: Corticosteroids avoidvisual acuity loss

Dear Editor,

Scleritis is a sight-threatening disease that can result invisual acuity loss in up to 30% of patients.1 The most com-mon etiologies of scleritis are auto-immune systemic dis-eases such as rheumatoid arthritis and Wegener’sgranulomatosis. Infectious and post-infectious scleritis ac-count for 7.5% of the causes of scleritis in a series of 97cases observed over a 12-year period.2 Viruses (VZV, EBV,etc.), bacteria (tuberculosis, syphilis, etc.), parasites(Toxoplasma, etc.) and fungi (Aspergillus, etc.) have beenreported to cause scleritis.1 Only two cases of group AStreptococcus (GAS) associated scleritis with uveitis havebeen reported in the literature.3 We describe the case ofa 60-year-old woman of 57 kg that presented with painfulred eyes headache and malaise, and severe acuity loss, re-vealing severe scleritis, with no associated uveitis. Scleritisresolved promptly after systemic corticosteroid treatment.

for 3 months. After one month, visual acuity was 20/20 inboth eyes and her CRP was normal and all symptoms had re-solved after 3 months (Fig. 1, day 90). One year later, thepatient had no recurrence of any symptom.

Although most GAS infections are usually mild, seriouscomplications might occur: suppurative complications atearly onset, and immune complications at late onset (acuterheumatic fever or acute post-streptococcal glomerulone-phritis). For unknown reasons, antibiotic treatment canprevent acute rheumatic fever but not acute post-streptococcal glomerulonephritis.4 Post-streptococcal ocu-lar complications are less known than kidney or articular lo-cations.5 Since its first description by Cokingtin and Han6 in1991, cases of post-streptococcal uveitis have been re-ported, associated with scleritis only in two patients.5,7

The diagnosis of a first case of post-streptococcal scleritiswith no other eye disorder was retained because i) the pa-tient had no sign of immune disorder (no symptom in thepast, no significant rate of anti nuclear antibody, and no im-mune disorder one year after corticosteroid treatment wasdiscontinued) ii) the scleritis occurred 10 days after the on-set of a proven GAS tonsilitis, a time difference that is usualfor other post-streptococcal immune disorders iii) the pa-tient presented with hyperacute symptoms and intensechemosis, which are unusual in auto-immune systemic re-lated scleritis. The current case of scleritis occurred de-spite the antibiotic treatment of the precessive GAS