Serogroup distribution of Shigella in Ile-Ife, southwest Nigeria.

BACKGROUND: Shigellosis is endemic throughout the world and Shigella spp. is among the most common pathogens responsible for bacterial diarrhoeal diseases. Death attributed to shigellosis is common in developing countries, where affected populations are immunologically compromised due to poor nutrition and background infections. AIM: To investigate the serogroup distribution of Shigella spp. recovered from clinically diagnosed cases of gastroenteritis and acute diarrhoea among children (0-5 years) in Ile-Ife, southwest Nigeria between September 2003 and September 2006. METHODS: The isolates were identified and characterized biochemically and serologically. RESULTS: Out of 102 Shigella isolates identified, 45 (44%) were S. flexneri, 26 (25%) were S. dysenteriae, 19 (19%) were S. boydii, 6 (6%) were S. sonnei and 6 (6%) were untypable strains. CONCLUSIONS: We conclude that Shigella serogroups can be considered an important aetiological agent of acute diarrhoea and mortality among children in Ile-Ife, southwest Nigeria.

Antibiotic resistance and virulence properities in escherichia coli stranins from cases of urinary tract infections

This study determined E. coli resistance to commonly used antibiotics together with their virulence properties in Ile-Ife; Nigeria. A total of 137 E. coli isolates from cases of urinary tract infection were tested for their sensitivity to commonly used antibiotics and possession of virulence factors using standard methods. Their ability to transfer resistance was also determined. The isolates demonstrated a high and widespread resistance (51.1 to 94.3) to all the antibiotics used except Nitrofurantoin (7.3). A total of 50 (36.5 ) of the isolates were resistant to 10 of the eleven antibiotics employed. Sixty three per cent (63) of the 107 trimethoprim resistant E. coli transferred their resistances while amoxicillin; gentamycin; augmentin; tetracycline and erythromycin were co-transferred with trimethoprim. Fifty one (37.2) of these multi-resistant isolates possessed one or more virulent factors. The study concluded that urinary tract infection due to E. coli in Ile-Ife may be difficult to treat empirically except with nitrofurantoin; due to high resistance to commonly used antibiotics. It is imperative that culture and susceptibility tests be carried out on infecting pathogen prior to treatment; in order to avoid treatment failure and reduce selective pressure that could result in the spread of uropathogenic E. coli in the environment

Disinfectants/antiseptics in the management of guinea worm ulcers in the rural areas.

The effectiveness of trichlorophenol (TCP), chlorhexidine gluconate plus cetrimide (Savlon) and Izal in inhibiting the growth of bacterial isolates from guinea worm ulcers was investigated. Using an adaptation of the method of Russell and Furr (Russell, A.D., Furr, J.R., 1977. The antibacterial activity of a new chloroxylenol preparation containing ethylenediamine tetraacetic acid. J. Appl. Bacteriol. 43, 253-260) the minimum inhibitory concentration (MIC) values of the three anti-microbial agents for each of the isolated bacteria was determined. Water drawn from the rural guinea worm endemic sites was autoclaved and used for the various dilutions of the anti-microbial agents. At the manufactures' recommended use-dilutions in cases of wounds/cuts/sores, Savlon showed greater effectiveness than Izal and TCP in this order. Probable organic and inorganic inhibitors in water that is usually employed in diluting anti-microbial agents in the rural areas for the dressing of guinea worm ulcers very likely had greatest effect(s) on TCP and least effect(s) on Savlon.

Unusual recovery of animal staphylococci from septic wounds of hospital patients in Ile-Ife, Nigeria.

Two Staphylococcus species--Staphylococcus gallinarum and Staphylococcus sciuri--previously known to be of animal origin have been isolated from infected wounds of hospital patients in Ile-Ife, Nigeria. These organisms were non-typable at both RTD and 100 x RTD and did not produce beta-lactamase detectable by the normal methods. Their actual involvement in the infection is not immediately clear, but their resistance to most common antibiotics, in addition to the production of DNase and phosphatase, may be indicating that these species could become important skin contaminants in humans and opportunistic zoonotics.

Antimicrobial effectiveness of six paradols. 1: A structure-activity relationship study.

The pattern of antimicrobial effectiveness of (0)-, (2)-, (3)-, (4)-, (8)- and (9)-paradols was studied. (3)- Paradol was more active than the other homologues with a minimum inhibitory concentration (MIC) of 1 mg/ml when tested against Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus and Botryodiplodia theobromae. At 0.2 mg/ml, (3)-paradol completely inhibited the spore germination of Trichophyton mentagrophytes and after 3 h of exposure at 0.5 mg/ml, it inhibited the growth of a heavy inoculum of Staphylococcus aureus (1 X 10(9) cells/ml).

Mechanisms of resistance of staphylococci grown in plasma to polymorph bactericidins.

The mechanisms whereby staphylococcal strains grown in plasma assume increased resistance to polymorph bactericidins were investigated. Observations reported here showed that cultural conditions could determine the path of conversion to resistance. Staphylococcal strains and mutants lacking either free coagulase or clumping factor or both all showed enhanced resistance after 10 h incubation in plasma proteins, thus giving no clear indication that these factors were involved in the interactions. In fact, prolonged incubation in bovine serum albumin (22 h) and ordinary broth medium (24 h) also resulted in increased resistance. A distinction between staphylococcal factors interacting specifically with plasma proteins and such non-specific conversions was obtained in two different ways. Stripping of a hypothetical surface protein by treatment with trypsin or 2 M potassium bromide rendered plasma- but not 24 h-broth organisms susceptible, indicating protein coating of plasma-grown organisms. Also free coagulase-positive strains and mutants incubated in plasma for 30 min were converted while those lacking both or possessing clumping factor alone were not. It therefore appears that one of the mechanisms of acquiring resistance involves a rapid interaction between staphylococcal-free coagulase and fibrinogen, resulting in the deposition of fibrin or fibrin derivatives on the bacterial surface.

Evaluation and use of the drug inhibition method of measuring intracellular killing in differentiating between staphylococci grown in vivo and in vitro.

A Staphylococcus aureus strain grown once in vivo in rabbit pleural cavities was appreciably more resistant to killing by soluble polymorph bactericidins than its broth-grown counterpart. Parallel results were obtained using an adaptation of Solberg's drug-inhibition method of measuring intracellular killing after critical aspects of it had been evaluated and modified. Individual in vivo grown organisms were surrounded by a layer of less dense material which was not capsular in nature but which made the organisms clump together. This surface coating was lost on subculture in vitro, resulting in a reversion to broth-like susceptibility, thus indicating that the surface coating was largely responsible for the enhanced resistance and that it resulted from interactions between staphylococci and components of the rabbits' natural body fluids. Consequently, growth in plasma produced organisms which mimicked in vivo grown organisms in clumping, surface coating and in resistance to killing. The use of plasma-grown staphylococci in further studies of likely resistance mechanisms in vivo is discussed.