Antibiotic resistance patterns in bacterial
strains isolated in Ethopia
Jimma Hospital Pharmacy Department, Jimma, Ethiopia
The biological equilibrium between the antimicrobial agents developed
by man and the pathogenic microorganisms being treated is progressively shifting in favor of the pathogenic microorganism.
Darwin's theory of "struggle for existence and survival of the fittest" is a fact that cannot be ignored
with regard to human and animal pathogens.
The greater part of the health hazards of Ethiopia are microbiological
in origin. Yet despite hordes of patients suffering febrile diseases, most hospital laboratories in Ethiopia are
geared to provide determination of hemoglobin, white cell-total and differential counts, blood sedimentation rates,
analysis of urine for sugar and protein and microscopy of saline preparation of stool, but the health laboratories
for microbiological work are not well equipped and staffed.
Ideally, culture and antibiotic susceptibility should be performed
for the proper management of microbial infections. It is not, however, always possible to delay initiation of
treatment until the laboratory reports are available. In such instances and without culture facilities, epidemiological
information and antibiotic sensitivities of the bacterial strains frequently isolated in a particular region are
very important as a guide for empiric treatment.
In Ethiopia where bacteriological laboratory facilities are non-existent
in most hospitals, let alone clinics, studies concerning antibiotic resistances are very few, though very much
needed. The unrestricted use of limited supplies of antibiotics has resulted in higher number of resistances to
antibiotics such as ampicillin, cotrimoxazole, penicillin, streptomycin nd tetracycline. Therefore, some insight
into the patterns of antibiotic resistance in frequently isolated bacterial strains in Ethiopia is necessary before
recommendations for an active antibiotic policy are prepared.
The limited number of studies on drug resistances in Ethiopia are
critically reviewed to get some insight into the patterns of antibiotic resistance. Studies reviewed in this paper
were selected from different locally published journals and newsletters such as Eth. Med. J., Bulletin of JIHS,
Ethiop. J. Health Dev., Eth. Pharm. J., and NRIH Newsletter. Because of unavailability of journals and newsletters,
those studies published outside Ethiopia were excluded. More than two-thirds of the reviewed studies were conducted
in the capital city, Addis Ababa, because the potential health laboratories for microbiological work are not well-equipped
and staffed in peripheral areas of the country so that patients are sent to the capital city for further microbiological
Those studies that could provide not only information on the resistance
patterns of the most commonly isolated microorganisms but also on correctness of therapy, were selected for the
purpose of this paper.
Typical patients' samples in the selected studies include urine,
pus, ear, nose and throat swabs, sputum and blood samples, and face and skin lesions. Antibiotic susceptibility
tests in each study were performed following the Kirby-Bauer procedure (1-14). To summarize the relevant data
available from the selected studies systematically, the following parameters were used, i.e. source, year published,
study samples, types of isolates, prevalence rate and prevalence of microbial resistance rates to antimicrobial
agents such as ampicillin, tetracycline, cotrimoxazole, chloramphenicol, gentamicin, kanamycin and cephalosporins.
(The terms "antibiotic" and "antimicrobial agent" are used interchangeably in this paper).
The selected data were summarized and tabulated. The prevalence
rates were not indicated in the table for those studies which used the actual resistance isolates for antibiotic
The most frequently isolated bacterial strains (Table 1,2) were
E. coli, Klebsiella, and Proteus species among the gram-negative cocci, and staphylococcal group, among gram-positive
cocci, with the mean prevalence rate of 23.5%, 17.5%, 12.2% and 30.5% respectively. Pseudomonas spp., N. gonorrhoeae
and Enterobacter were also reported among the gram-negative species, though they were not as common as the E. coli,
Klebsiella and Proteus spp. (1-14).
Staphylococcal infections are very common because the conditions
that permit the organism to gain access to the tissue are numerous and frequent. It is the etiological agent of
diverse clinical disease and one of the most common bacterial isolates causing bacteremia in hospital patients,
the other two being E. coli and Streptococcus pneumoniae (1,7-15).
The most frequently isolated bacterial strains in this review were
also similar to the recently reported from Hungary (15).
As it has been shown from the tables, the antibiotic resistance rates for respective isolated bacterial strains
increased from time to time. Among gram-negative cocci, a 45.7% and 84.6% resistance rate of E. coli, and Klebsiella
spp. to ampicillin in 1970 (1) were increased to mean resistance rates of 60% and 95% between 1980-92 respectively
(6-13). About 2% of resistance rates of E. coli, Klebsiella and Proteus spp. for gentamicin in 1980-83 (6-8) increased
in 1990-93 (12-14).
Of gram-positive cocci, the staphylococcus group, which was having
a less resistant rate in 1970, were also shown to increase to a high resistance rate between 1980-903 to penicillin,
gentamicin, erythromycin, cotrimoxazole and cephalosporins. Similarly, an increased resistance rate also recorded
to other antimicrobial drugs such as chloramphenicol, tetracycline, cotrimoxazole and cephalosporins for both gram-negative
and gram-positive cocci (1-14).
As compared with data from other countries, there is a bacterial
high antimicrobial resistance rate in Ethiopia (15).
Whatever the mechanisms of resistance, different studies agreed that, the major reason for the emergence of antibiotic
resistance in Ethiopia is the use of antibiotics (1-14). The background to this is a rather complex maze of circumstances
and interests. Any housewife with a sick child may go into a pharmacy and take home a flavored syrup of antibiotics.
The transactions differ not all from buying can of beans, and it is clear that the various flavors may determine
the choice of antibiotics.
Apologists explain that until doctors are more numerous and easily
accessible, it is ethical to allow the public direct access to most drugs. They appear again to explain that until
there is enough healthy personnel, nothing can be done about establishing standards of local medical practices.
it is also said that enforcing pharmacy regulations would be difficult and financially impossible (16).
In the absence of easy access to bacteriology laboratories, doctors
are more carefree or careless than they might otherwise be, embark prematurely on broad spectrum antibiotic therapy,
then jump as required from one antibiotic to another in search of magic resolution of unidentified disease for
too many occasions.
The unrestricted availability of antibiotics in many parts of the country which encourage self-medication with
subtherapeutic dosages, dispensing of such drugs for prophylactic use, and to meet patients wishes that the original
complaints and also taking antibiotics over the counter (OTC) are other factors that have contributed to a high
resistance rate. Therefore a policy aiming at the rational use of drugs needs to emphasize appropriate drug use,
if sound prescribing practices and the informed use of drugs by patients and public are to be achieved.
These limited studies confirmed that the knowledge of the incidence
and spread of resistant drugs, both current and discontinued for the possible influences they may have on subsequent
therapy should need further study to prepare a compiled guideline on the use of antibiotics. Antibiotic strategy
that will permit the availability and supply of antibiotics in accordance to the level of institution and education
as to their proper use within the framework of clinical expectations and economy of the country is also necessary.
It would certainly not be too early to consider with priority the investigation of microbial drug-resistance, and
the control of the present misuse of antibiotics should be given in the list of nationally-financed health programs.
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