Plasmodium falciparum: Inhibition of Sporogonic Development in Anopheles stephensi by Gram-Negative Bacteria

• Published in: Experimental parasitology Vol. 77; no. 2; pp. 195 - 199
• Main Authors: Pumpuni, C.B., Beier, M.S., Nataro, J.P., Guers, L.D., Davis, J.R.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.09.1993; Elsevier
• Subjects: Animals; Anopheles - microbiology; Anopheles - parasitology; ANOPHELES STEPHENSI; BACTERIA GRAM NEGATIVA; BACTERIE GRAM NEGATIF; Biological and medical sciences; BIOLOGICAL CONTROL; CONTROL BIOLOGICO; CONTROL DE ENFERMEDADES; CONTROLE DE MALADIES; Culicidae; Diptera; DISEASE CONTROL; DISEASE VECTORS; Female; Formaldehyde; Fundamental and applied biological sciences. Psychology; GRAM NEGATIVE BACTERIA; Gram-Negative Bacteria - physiology; Gram-Positive Bacteria - physiology; INFECCIONES POR PROTOZOOS; Invertebrates; Lipopolysaccharides - pharmacology; LUTTE BIOLOGIQUE; MALARIA; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; PLASMODIUM; PLASMODIUM FALCIPARUM; Plasmodium falciparum - drug effects; Plasmodium falciparum - growth & development; PROTOZOAL INFECTIONS; PROTOZOOSE; PUBLIC HEALTH; SALUD PUBLICA; SANTE PUBLIQUE; VECTEUR DE MALADIE; VECTORES; VECTORS; Vectors. Intermediate hosts; Protozoa; Protozoal disease; Malaria; Insecta; Parasite; Infection; Plasmodium falciparum; Anopheles stephensi; Microbiological control; Arthropoda; Culicidae; Development; Bacteria; Inhibition; Invertebrata; Sporozoa; Sporogonia; Vector; Diptera; Gram negative bacteria
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1006/expr.1993.1076

We investigated the effects of bacteria on Plasmodium falciparum sporogonic development in Anopheles stephensi. Four gram-negative (Escherichia coli H243, E. coli HB101. Pseudomonas aeruginosa, and Ewingella americana) and two gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) bacterial strains were used in the study. Tenfold dilutions of bacteria suspended in phosphate-buffered saline were mixed with an infectious meal of gametocyte-enriched cultures and fed to adult mosquitoes. All gram-negative bacteria strains partially or completely inhibited oocyst formation at different concentrations. Additionally, geometric mean number of oocysts showed a correspondingly significant decrease with increasing bacterial concentration (P < 0.001). In contrast, gram-positive bacteria strains did not have any inhibitory effects on oocyst formation even at very high concentrations. Oocyst development was not affected by: (i) culture supernatants of E. americana, (ii) formalin-treated E. coli H243, (iii) lipopolysaccharide of E. coli J5 (mutant of 0111:B4). These studies show that gram-negative but not gram-positive bacteria affect sporogonic-stage development of P. falciparum in A. stephensi. Inhibition of parasite acquisition may be an attribute of specific or nonspecific cytoadherence properties of gram-negative bacteria to the parasites.