Previous Article | Next Article 
Antimicrobial Agents and Chemotherapy, June 2009, p. 2450-2454, Vol. 53, No. 6
0066-4804/09/$08.00+0 doi:10.1128/AAC.01282-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Antimicrobial Susceptibility and Mechanisms of Resistance in Shigella and Salmonella Isolates from Children under Five Years of Age with Diarrhea in Rural Mozambique
Inácio Mandomando,1,2,3*
Dinis Jaintilal,1
Maria J. Pons,3,4
Xavier Vallès,1
Mateu Espasa,1
Laura Mensa,3
Betuel Sigaúque,1,2,3
Sergi Sanz,3
Jahit Sacarlal,1,3,5
Eusébio Macete,1,3,6
Fátima Abacassamo,1,5
Pedro L. Alonso,1,3 and
Joaquim Ruiz3,4
Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique,1 Instituto Nacional de Saúde, Ministério de Saúde, Maputo, Mozambique,2 Centre de Recerca en Salut Internacional de Barcelona (CRESIB), Hospital Clínic/IDIBAPS, Universitat de Barcelona, Barcelona, Spain,3 CIBER, Epidemiologia y Salud Publica (CIBERESP), Barcelona, Spain,4 Faculdade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique,5 Direcção Nacional de Saúde, Ministério de Saúde, Maputo, Mozambique6
Received 24 September 2008/ Returned for modification 22 January 2009/ Accepted 22 March 2009
The antimicrobial susceptibility and mechanisms of resistance of 109 Shigella and 40 Salmonella isolates from children with diarrhea in southern Mozambique were assessed. The susceptibility to seven antimicrobial agents was tested by disk diffusion, and mechanisms of resistance were searched by PCR or colorimetric method. A high proportion of Shigella isolates were resistant to chloramphenicol (Chl) (52%), ampicillin (Amp) (56%), tetracycline (Tet) (66%), and trimethoprim-sulfamethoxazole (Sxt) (84%). Sixty-five percent of the isolates were multidrug resistant. Shigella flexneri isolates were more resistant than those of Shigella sonnei to Amp (66% versus 0.0%, P < 0.001) and Chl (61% versus 0.0%, P < 0.001), whereas S. sonnei isolates presented higher resistance to Tet than S. flexneri isolates (93% versus 64%, P = 0.02). Resistance among Salmonella isolates was as follows: Tet and Chl, 15% each; Sxt, 18%; and Amp, 25%. Only 3% of Salmonella isolates were resistant to nalidixic acid (Nal), and none to ciprofloxacin or ceftriaxone (Cro). Among Salmonella isolates, multiresistance was found in 23%. Among Shigella isolates, antibiotic resistance was related mainly to the presence of oxa-1-like β-lactamases for Amp, dfrA1 genes for Sxt, tetB genes for Tet, and Chl acetyltransferase (CAT) activity for Chl. Among Salmonella isolates, resistance was conferred by tem-like β-lactamases for Amp, floR genes and CAT activity for Chl, tetA genes for Tet, and dfrA1 genes for Sxt. Our data show that Shigella isolates are resistant mostly to the most available, inexpensive antibiotics by various molecular mechanisms but remain susceptible to ciprofloxacin, Cro, and Nal, which is the first line for empirical treatment of shigellosis in the country.
* Corresponding author. Mailing address: Centro de Investigação em Saúde da Manhiça (CISM), Vila da Manhiça, Rua-12, P. O. Box. 1929, Maputo, Mozambique. Phone: 258 21 810 002. Fax: 258 21 810 181. E-mail: inacio.mandomando{at}manhica.net
Published ahead of print on 30 March 2009.
Antimicrobial Agents and Chemotherapy, June 2009, p. 2450-2454, Vol. 53, No. 6
0066-4804/09/$08.00+0 doi:10.1128/AAC.01282-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»