Microbial Profile of Wound Infections in a Nigerian Teaching Hospital

Background: This study set out to investigate the aerobic and facultative anaerobic microbial profile of wound infections in the University of Port Harcourt Teaching Hospital. Methods: A total of 202 wound swabs samples were randomly collected from both in and out-patients presenting at the facility. One hundred and thirteen(55.9) of the samples were collected from males while 89(44.6) were from females. The age of the patients ranged from 32 days to 80 years. Samples were processed following standard operating protocols in the microbiology laboratory. Results: Of the 202 samples examined; 164(81.2) had microbial isolates while 38(18.8) yielded no growth. Among the 164 samples with positive microbial growth; 124(75.6) had single isolates while 40(24.4) had polymicrobial growth. Of the 113 males studied; 90(79.7) had microbial growth while 23(20.4) had no growth. Similarly; of the 89 females studied; 74(83.2) had microbial growth while 15(16.9) had no growth. Furthermore; the total microbial isolates from the study was 206. Gram-negative bacterial organisms accounted for 124(60.1) as against 82(39.9) from the Gram-positive's (p

Incidence and biotyping of Aeromonas species from the environment.

A survey was carried out to establish the incidence rate of Aeromonas species in various environmental samples with a view to ascertaining their reservoirs and distinguishing the biotypes. High rates of isolation were obtained from snails and water. This indicates that these samples are likely reservoirs and therefore constitute high sources of human infection. Low incidence rates were realised from poultry, cattle and humans, thus suggesting that these samples may be transient hosts. Two species of Aeromonas were isolated: A. sobria, and A. hydrophila which was further split into two biotypes, viz A. hydrophila subspecies hydrophila and A. hydrophila subspecies anaerogenes. All were involved with infections in humans.

Virulence factors from Aeromonas species.

Isolates (116) of Aeromonas were obtained from various sources and subjected to tests to establish their virulence factors. A high number of the isolates (69.8%) were found to be enterotoxigenic. The isolates from snails had more enterotoxigenic strains (73.3%), while those from cattle faeces had the lowest (33.3%). Haemolysin production was found to be high (60.3%) amongst the isolates, and human isolates gave the highest number of haemolysin producing strains (70.6%), while the least number (33.3%) was obtained from cattle strains. About 50% of the strains produced both enterotoxin and haemolysin. The enzyme profile of the isolates included amylase, lecithinase, lipase and protease. There was no definite pattern in the elaboration of these enzymes and the production of haemolysin and enterotoxin, thus inferring that the production of these factors is not specific to the source. Two isolates were seen to produce none of these enzymes, and one was positive for enterotoxin and haemolysin production, leaving only one isolate which yielded none of these factors. The work adds more support to the pathogenicity of Aeromonas species, and indicates the existence of non-pathogenic strains.

Microbiological and Sensory Quality Changes in Unwrapped and Wrapped Sliced Watermelon.

Experiments were done to determine the major genera and groups of microflora which grow on unwrapped and wrapped slices of watermelon stored at 5 and 25°C for up to 8 d. Changes in sensory qualities of stored watermelon were also monitored. Pseudomonas , Escherichia coli , Enterobacter and micrococci comprised the predominant microflora, regardless of storage temperature. Growth was slower on wrapped watermelon than on unwrapped watermelon. Subjective ratings for color, aroma, appearance, flavor and texture of unwrapped watermelon stored at 5°C decreased more rapidly than ratings for wrapped slices. Results from objective measurements of color suggested that dulling and darkening was most rapid on the surface of unwrapped watermelon, and this was attributed to more rapid oxidation of pigments when exposed to air. Objective measurement of firmness showed that wrapped watermelon retained structural integrity for a longer time than unwrapped watermelon; however, subjective ratings for texture were not correlated with these values, indicating that texture is less critical than color and flavor when overall judgments are made on sensory quality of stored watermelon.

Asymptomatic bacteriuria in the Port Harcourt metropolis of Nigeria.

The Port Harcourt metropolis of Nigeria was screened to establish the prevalence of asymptomatic bacteriuria (ABU) over a 3 year period. An occurrence rate of 15% was detected. The females presented a higher incidence rate (9%) than the males (6%). Previous history of urinary tract infection (UTI) was seen to be contributory to ABU; so also was sexual activity. Of the isolates obtained, Escherichia coli was found to be predominant (45%). An isolation rate of 3.7% was realised for Staphylococcus epidermidis. This emphasizes its role in UTI. The advantages of screening for ABU was examined and it is suggested that individuals should be screened for ABU at least twice a year.

Chemical composition of the cell wall of Cryptostroma corticale: effects of antibiotics on cell morphology.

The chemical composition of the cell wall from four strains of Cryptostroma cortical was examined and was found to be of the chitin-glucan type. The composition was consistent among the four strains. The effects of the antibiotics repamycin, ramihyphin, aculeacin-A, cytochalasin and polyoxin-D on cell morphology were studied, using electron and light microscopy.

Electron microscope study of Cryptostroma corticale.

An ultrastructural study of Cryptostroma corticale has been carried out with scanning and transmission electron microscopes. The usual features in fungi, as well as features characteristic of the family, were shown. It was noted that lomasomes and myelin-type structures were demonstrated by the two fixatives used. Their significance is discussed.