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This was a cross-sectional descriptive study carried out at Mama Lucy Kibaki
Hospital for a period of 6 months, between October 2018 and March 2019.
Mama Lucy Kibaki Hospital is a level 5 public health facility located in the
eastern part of Nairobi city, Kenya.
Study population
These were surgical patients with surgical site infections. These patients were
drawn from the surgical wards, maternity wards and pediatric ward.
Inclusion and exclusion criteria
The study included patients of all age groups with surgical site infection
following general, obstetrics and gynecological surgeries. Those patients who
did not consent were excluded.
Sampling
Patients with surgical site infection were identified by surgeons during routine
ward rounds and the clinical information documented in the patient file. The
same information was relayed to the principal investigator through the
clinicians. The identified patients were taken through the research process
and informed consents obtained. A serialized structured questionnaire was
used to collect additional patient clinical data.
Sample collection
The pus swabs were aseptically obtained from 58 patients with clinical
evidence of surgical site infection (drainage from an incision) within the
research period. After the wound immediate surface exudates and
contaminants were cleansed off with sterile moistened gauze and normal
saline solution. The pus was collected using a moistened sterile cotton swab
from the deep viable tissues of the wound by the Levine method (Cooper,
2010). The collected swab was then placed in a tube with Stuart transport
medium and the replaced cap tightened. Two pus swabs were collected from
each patient, one for gram stain and the other for culture. All the swabs were
carefully labeled and transported immediately to Kenyatta university
laboratory in appropriate leak-proof specimen transport bags.
Bacterial culture and identification
Upon reaching the laboratory, all the pus swabs were carefully checked and
their details entered into the investigator’s booklet. Smears of the pus swabs
were prepared, gram stained and examined microscopically. The other swabs
from each patient were inoculated on MacConkey agar and blood agar and
the inoculated plates incubated at 35 to 37°C for 24 h. After incubation, the
plates were examined for growth. Colony characteristics such as swarming
growth and hemolysis on blood agar, changes in physical appearance in
differential media, and enzymatic activities of the organisms were used for
preliminary bacterial identification. Biochemical tests such as catalase,
coagulase, urease, indole, methyl red, Voges Proskauer and citrate (IMViC)
tests were performed for the identification of the various bacteria.
Antibiotic susceptibility testing
Antibiotic susceptibility testing was performed on Mueller Hinton agar using
various antibiotics by Kirby Bauer disc diffusion method as per standards
prescribed in bacteriology (Hudzicki, 2016). Using a sterile swab, Mueller
Hinton agar surface was uniformly coated with the suspension of the test
organism matching 0.5 McFarland turbidity standard. Following incubation of
test plates and controls at 35°C for 24 h, the plates were examined for
confluent growth. Escherichia coli ATCC 25922 and Staphylococcus
aureus ATCC 25923 were used as control strains. The zones of inhibitions
were determined using breakpoints provided by the Clinical and Laboratory
Standards Institute and British society for antimicrobial chemotherapy (CLSI,
2016;BSAC, 2013). The following antibiotics were tested for resistance;
Chloramphenicol (50 ug), Vancomycin (30 ug), Amoxycillin (30 ug),
Doxycycline (30 ug), Ciprofloxacin (30 ug), Cefepime (30 ug), Ceftriaxone (30
ug), Amikacin (30 ug), Gentamicin (30 ug), Oxacillin (1 ug), Cotrimoxazole (25
ug), Azithromycin (15 ug) and Ampicillin (10 ug). These antibiotics were
selected based on the availability and prescription frequency of these drugs in
the study area.
Data analysis
Data were entered in excel, cleaned, and the information exported to IBM
statistical package for the social sciences version 20.
Descriptive statistics; mean and percentages were determined. Pearson chi-
square test was used to determine the association of social demographic data
and the different bacteria isolates. P-value of < 0.05 was considered to
indicate statistically significant differences. Finally, the results were presented
using tables.
Ethical consideration
Ethical approval was given by Kenyatta University Ethics Review Committee
(KUERC) reference no PKU/700/1772. Informed consent was obtained by the
signing of informed consent forms by adults. For participants below 18 years,
parents or legal guardians would sign the consent forms on their behalf. All
patients’ records were kept anonymous.
RESULTS
https://ir-library.ku.ac.ke/server/api/core/bitstreams/4a429149-3914-4fd0-8003-4f3d7ce8e82c/content
