Indian Journal of Medical Microbiology IAMM  | About us |  Subscription |  e-Alerts  | Feedback |  Login   
  Print this page Email this page   Small font sizeDefault font sizeIncrease font size
 Home | Ahead of Print | Current Issue | Archives | Search | Instructions  
Users Online: 2204 Official Publication of Indian Association of Medical Microbiologists 
  Search
 
  
 ~  Similar in PUBMED
 ~  Search Pubmed for
 ~  Search in Google Scholar for
 ~Related articles
 ~  Article in PDF (778 KB)
 ~  Citation Manager
 ~  Access Statistics
 ~  Reader Comments
 ~  Email Alert *
 ~  Add to My List *
* Registration required (free)  

 
 ~  Abstract
 ~ Introduction
 ~ Case Reports
 ~ Discussion
 ~  References
 ~  Article Figures

 Article Access Statistics
    Viewed4955    
    Printed160    
    Emailed1    
    PDF Downloaded161    
    Comments [Add]    
    Cited by others 2    

Recommend this journal

 


 
  Table of Contents  
CASE REPORT
Year : 2011  |  Volume : 29  |  Issue : 4  |  Page : 422-425
 

Isolation of Shewanella algae from rectal swabs of patients with bloody diarrhoea


Department of Microbiology, Assam Medical College and Hospital, Dibrugarh, Assam 786 002, India

Date of Submission05-Mar-2011
Date of Acceptance01-Jul-2011
Date of Web Publication24-Nov-2011

Correspondence Address:
R Nath
Department of Microbiology, Assam Medical College and Hospital, Dibrugarh, Assam 786 002
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0255-0857.90186

Rights and Permissions

 ~ Abstract 

Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. It was infrequently recovered from clinical specimens probably because of inadequate processing of non-fermenting oxidase-positive gram-negative bacilli. We report here isolation of S. algae in pure culture and mixed with E. coli from two cases of acute gastroenteritis with bloody mucous containing diarrhea occurring at the same time. As this organism is not a normal flora of the gut, the possible source of infection may be fish contaminated with the organism. Whether this bacterium can be considered an enteric pathogen needs to be evaluated. The cases were clinically diagnosed as acute bacillary dysentery. The bacterium was identified by 16S r-RNA gene sequence analysis.


Keywords: Dysentery, Shewanella algae, Shewanella spp


How to cite this article:
Nath R, Saikia L, Choudhury G, Das P P. Isolation of Shewanella algae from rectal swabs of patients with bloody diarrhoea. Indian J Med Microbiol 2011;29:422-5

How to cite this URL:
Nath R, Saikia L, Choudhury G, Das P P. Isolation of Shewanella algae from rectal swabs of patients with bloody diarrhoea. Indian J Med Microbiol [serial online] 2011 [cited 2019 Sep 20];29:422-5. Available from: http://www.ijmm.org/text.asp?2011/29/4/422/90186



 ~ Introduction Top


Shewanella is a marine bacteria rarely implicated as a human pathogen. Two species of importance are Shewanella algae and Shewanella putrefaciens. [1] S. algae may cause a variety of clinical symptoms in humans ranging from skin and soft tissue infections to bacteraemia and osteomyelitis. [2],[3],[4],[5],[6],[7] It is an oxidase-positive, hydrogen sulphide producing Gram negative bacilli. It was infrequently recovered from clinical specimens probably because of inadequate processing of non-fermenting oxidase-positive gram-negative bacilli. We report here isolation of S. algae in pure culture and mixed with E. coli from two cases of acute gastroenteritis with bloody mucous containing diarrhoea occurring at the same time. Whether this bacterium can be considered an enteric pathogen needs to be evaluated. The cases were clinically diagnosed as acute bacillary dysentery.


 ~ Case Reports Top


Case 1

A 70-year-old woman along with another member of her family suffered from bloody mucous containing diarrhoea with a frequency of 5-6 times in a day, which started 12 h after consuming dinner in a remote village of Lakhimpur district, Assam, in September 2010. Both of them consumed dinner with rice and fish. There was no history of fever or vomiting. Rectal swab was collected by health personnel in Cary Blair transport medium before starting empirical therapy for acute bacillary dysentery with ciprofloxacin tablet 500 mg 8 hourly. The other family member was unavailable for taking sample and was also treated empirically for bacillary dysentery.

Case 2

We report a case of a 20-year-old man with a history of passing bloody mucous containing stool since last 24 h. There was a history of eating fish and rice for dinner 12 h earlier. No history of fever or vomiting could be found. Both the patients belonged to the same village and the symptoms started at the same time. Other members of his family were not affected. Whether both the patients brought the fish from the same source was not known. There was no history of taking any seafood or visiting any sea side in both the cases. Even though we could not implicate any food directly for lack of microbiological evidence, fish can be suspected as the possible source. In both the families, 7 people consumed fish preparations and 3 persons were affected at the same time with the same symptoms (attack rate 42.8%). Hospitalization was not needed.

As the area is endemic for cholera and shigellosis, these rectal swabs were sent as a routine laboratory investigation for culture and sensitivity to the district level microbiology laboratory. Samples of other household members were not sent. Both the persons were otherwise not suffering from any general disease or local lesion. Source of drinking water was tube well. The samples were inoculated into MacConkey agar (BBL: Becton, Dickinson and Company, Sparks, MD, USA),  Salmonella More Details-Shigella agar (BBL: Becton, Dickinson and Company, Sparks, MD, USA), nutrient agar and also in alkaline peptone water (all; Hi-Media Laboratories Pvt Ltd, Mumbai, Maharashtra, India) to exclude Vibrionaceae group as these cases came from cholera endemic rural Assam and  Vibrio cholerae Scientific Name Search  01 ogawa was reported in that district recently. Culture plates were incubated at 37°C for 18-24 h, alkaline peptone water was incubated for 6-8 h and subcultured thereafter in MacConkey agar, TCBS (BBL: Becton, Dickinson and Company, Sparks, MD, USA) agar and nutrient agar.

In case 1, there was pure growth of non-lactose-fermenting colonies in MacConkey agar (10 4 CFU/plate), yellowish mucoid colonies in nutrient agar [Figure 1]. Colonies produced haemolysis in sheep blood agar media on subculture. Biochemically it was oxidase positive, catalase positive, nonfermenter in Difco oxidation-fermentation media, produced abundant H 2 S on triple sugar iron agar slant, decarboxylated ornithine, urea was hydrolyzed, glucose and maltose oxidized; lactose, mannitol, and sucrose not oxidized. The organism was presumptively identified as Shewanella spp. For confirmation, 16S r-RNA gene sequence analysis was done. DNA was extracted (QIAamp DNA Purification Kit, Qiagen; Hilden, Germany) and its quality was assessed on 1.2% agarose gel, a single band of high molecular weight DNA was observed. PCR amplification of the 16S rRNA-encoding gene was performed by using the universal primer pair 8F (5′ AGA GTT TGA TCC TGG CTC AG 3′) and 1492R (5′ ACG GCT ACC TTG TTA CGA CTT 3′) commercially obtained from Xcelris Labs Ltd, Ahmedabad, India. A single discrete PCR amplicon band of 1500 bp was observed when resolved on agarose gel. The PCR amplicon was purified to remove contaminants. Forward and reverse DNA sequencing reaction of the PCR amplicon was carried out with 8F and 1492R primers using Big Dye Terminator v3.1 Cycle sequencing kit on ABI 3730xl Genetic analyzer (Applied Biosystems Inc, California, USA). Consensus sequence of 1287 bp 16S rDNA gene was generated from forward and reverse sequence data using aligner software. The 16S rDNA gene sequence was used to carry out BLAST with the nr database of NCBI GenBank database. Based on maximum identity score the first 10 sequences were selected and aligned using multiple alignment software programme Clustal W. Distance matrix was generated using RDP database and the phylogenetic tree [Figure 2] was constructed using MEGA 4. The organism was found to have 100% similarity to S. alga (GenBank Accession Number: SA U91544.1).
Figure 1: Shewanella algae colony on nutrient agar. Upper half showing pure growth of transparent and mucoid colony of S. algae from case 1 (blue arrow). Lower half showing S. algae mixed with E. coli (red arrow) from case 2. (Subcultured from the original plate)

Click here to view
Figure 2: Phylogenetic tree; DQ386137.1 Shewanella algae; SAU91544.1 Shewanella algae; HM016087.1  Shewanella algae Scientific Name Search  ATCC 51192; HM016085.1; Shewanella sp.KJW23; FN997636.1 Shewanella algae, strain MS43; GQ372876.1 Shewanella algae strain MAS2740; GQ372875.1 Shewanella algae strain MAS2737; GQ372874.1 Shewanella algae strain MAS2736; FJ210809.1 Shewanella sp. QDHT-14; EU794725.1 Shewanella sp. CC-GIMA-1

Click here to view


Phylogenetic tree (constructed by the maximum likelihood method). The strain from our patient, which is called C33, was compared with other strains of Shewanella spp. already described in the literature.

In case 2,  Escherichia More Details coli colonies mixed with non-lactose-fermenting, mucoid, yellow, oxidase-positive colonies were detected, which were biochemically same as that of case 1. E. coli colonies were tested for the presence of enterotoxigenic pili by serotyping with K88, K99, and 987p and O157: H7 anti-sera (Denka Seikan, Tokyo, Japan), which were found to be negative. Other tests for detection of shiga-like toxin in E. coli isolate were not done. This non-lactose-fermenting bacterium was presumptively identified as S. algae as it was biochemically exactly same as that of case 1 and reported from the same area. Clonality of the strains was not tested. Antibiotic susceptibility was tested by Kirby-Bauer disc diffusion method (Clinical Laboratory Standards Institute), [8] using Mόller-Hinton agar and antibiotic discs from Hi-Media Laboratories Pvt Ltd. The strains were found to be sensitive to gentamicin, cotrimoxazole, amoxicillin-clavulanic acid, ciprofloxacin, norfloxacin, chloramphenicol, azithromycin, ofloxacin, and resistant to nalidixic acid, ceftazidime, and cefotaxime. The MICs to different antibiotics as determined by Hi-Comb (Hi-Media) were azithromycin 0.1 mcg/mL, ciprofloxacin 0.5 mcg/mL, chloramphenicol 0.1 mcg/mL, norfloxacin 2 mcg/mL, ofloxacin 2 mcg/mL, cefotaxime 30 mcg/mL, nalidixic acid ≥240 mcg/mL, and ceftazidime ?240?mcg/mL.≥240 mcg/mL. E coli 25922 was used as the control strain. Both the cases received ciprofloxacin tablet 500 mg 8 hourly as empirical therapy of acute bacillary dysentery after collection of the samples. The symptoms stopped after ciprofloxacin therapy within 24 h in both the cases. Repeat sample after 15 days did not yield the bacteria. Samples of water as well as samples of rectal swabs sent for culture from other patients of the same area did not yield the organism.


 ~ Discussion Top


Shewanella algae is a recently described marine bacterial species, which plays a role in the environment in the turnover of Fe (III) and other metal ions. [9],[10] Originally it was named as S. alga and later on it was changed to S. algae. [11],[12] It can play a role in in situ bioremediation. [13] S. algae may cause a variety of clinical symptoms in humans. [2],[3],[4],[5],[6],[7] Most of the infections are reported from a warm climate. It is not found as a normal flora of the gut and no other sample in the hospital yielded Shewanella spp., excluding laboratory contamination as a possible cause. In case 2, as it was isolated in mixed culture with E coli, the significance of the isolate remained doubtful. But in case 1, as it was in pure culture, the significance of the isolate remains to be seen. We searched for available literature and found only one case of acute gastroenteritis reported from India where the etiological evidence was said to be doubtful as it was mixed with E. coli and the patient later developed haemolytic uremic syndrome. [14] In both our cases though we could not implicate any food directly for lack of microbiological evidence, fish can be suspected as the possible source. Sea water is known to be the most common source though. Dominguez et al. in 1996 reported the presence of this organism in stagnant water. [10] Both our patients did not have any history of travelling to any seaside in the recent past. Shewanella spp., especially Shewanella putrefaciens is known to cause spoilage of marine fish, especially finfish. As it is also isolated from stagnant waters, it can cause spoilage of fish at warm temperature as this organism is mesophilic. S. algae is not found as a normal flora of gut; therefore, probable source of this organism in these two cases of dysentery could have been the contaminated fish. Most of the S. algae infections in man are skin and soft tissue infections. [4],[5] It has also been reported from a case of osteomyelitis. [7] Bacteraemia is also reported to occur with S. algae. [3] The pathogenic potential of the bacteria is said to be conferred by the haemolytic activity of S. algae. [1] No other case of gastroenteritis caused due to this organism could be found in the literature. Even though S. algae was isolated in pure culture in the first case, the possibility of other causes could not be ruled out because of lack of environmental and microbiological evidence of the organism in food material and water. Further environmental and clinical studies will be necessary to know the significance of the organism as an enteric pathogen.

This case report emphasizes the need to further characterize the oxidase-positive, H 2 S-producing non-fermenter gram-negative bacilli to know the prevalence of this organism even in areas not exposed to sea in different clinical specimens, including stool and rectal swab samples from diarrhoea and dysentery cases.

 
 ~ References Top

1.Khashe S, Janda JM. Biochemical and pathogenic properties of Shewanella alga and Shewanella putrefaciens. J Clin Microbiol 1998;36:783-7.  Back to cited text no. 1
    
2.Holt HM, Sogaard P, Gahrn Hansen B. Ear infections with Shewanella alga. A bacteriologic, clinical and epidemiologic study of 67 cases. Clin Microbiol Infect 1997;3:329-34.   Back to cited text no. 2
    
3.Myrug DS, Jung YS, Kang S, Song YA, Park KH, Jung S, et al. Primary Shewanella algae bacterimia mimicking Vibrio septicemia. J Korean Med Sci 2009;24:1192-4.   Back to cited text no. 3
    
4.Chen YS, Liu YC, Yen MY, Wang JH, Wang JH, Wann SR, et al. Skin and soft tissue manifestation of Shewanella putrefaciens infection. Clin Infect Dis 1997;25:225-9.  Back to cited text no. 4
    
5.Domínguez H, Vogel BF, Gram L, Hoffmann S, Schaebel S. Shewanella alga bacteremia in two patients with lower leg ulcers. Clin Infect Dis 1996;22:1036-9.   Back to cited text no. 5
    
6.Nozue H, Hayashi T, Hashimoto Y, Ezaki T, Hamaski K, Ohwada K, et al. Isolation and characterization of Shewanella alga from human clinical specimens and emendation of the description of S. alga Simidu et al., 1990, 335. Int J Syst Bacteriol 1992;42:628-34.   Back to cited text no. 6
    
7.Botelho Nevers E, Gouriet F, Rovery C, Paris P, Roux V, Raoult D, et al. First case of osteomyelitis due to Shewanella algae. J Clin Microbiol 2005;43:5388-90.  Back to cited text no. 7
    
8.National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial susceptibility testing. Approved Standards. 14 th ed. Document M100 S14. Villanova, PA: National Committee for Clinical Laboratory Standards; 2004.   Back to cited text no. 8
    
9.Caccavo F Jr, Blakemore RP, Lovley DR. A hydrogenoxidizing, Fe(III) reducing microorganism from the Great Bay Estuary, New Hampshire. Appl Environ Microbiol 1992;58:3211-6.   Back to cited text no. 9
    
10.Rossello Mora RA, Caccavo F, Osterlehner K, Springer N, Spring S, Schueler D, et al. Isolation and taxonomic characterization of a halotolerant, facultatively iron reducing bacterium. Syst Appl Microbiol 1994;17:569-73.   Back to cited text no. 10
    
11.Simidu U, Kumiko Tsukamoto K, Yasumoto T, Yotsu M. Taxonomy of four marine bacterial strains that produce tetrodotoxin. Int J Syst Bacteriol 1990;40:331-6.   Back to cited text no. 11
    
12.Truper HG, Clari LD. Taxonomic note: Necessary correction of specific epithets formed as substantives (nouns) in apposition. Int J Syst Bacteriol 1997;47:908-9.   Back to cited text no. 12
    
13.Caccavo F Jr, Ramsing N, Costerton JW. Morphological and metabolic responses to starvation by the dissimilatory metal reducing bacterium Shewanella alga BrY. Appl Environ Microbiol 1996;62:4678-82.  Back to cited text no. 13
    
14.Sharma KK, Kalawat U. Emerging infections: Shewanella - A series of five cases. J Lab Physicians 2010;2:61-5.  Back to cited text no. 14
[PUBMED]  Medknow Journal  


    Figures

  [Figure 1], [Figure 2]

This article has been cited by
1 Shewanella: a Marine Pathogen as an Emerging Cause of Human Disease
J. Michael Janda
Clinical Microbiology Newsletter. 2014; 36(4): 25
[Pubmed] | [DOI]
2 The genusShewanella: from the briny depths below to human pathogen
J. Michael Janda,Sharon L. Abbott
Critical Reviews in Microbiology. 2012; : 1
[Pubmed] | [DOI]



 

Top
Print this article  Email this article
 

    

2004 - Indian Journal of Medical Microbiology
Published by Wolters Kluwer - Medknow

Online since April 2001, new site since 1st August '04