Keywords
antibacterial agent - amoxicillin-potassium clavulanate combination - bacteria - anaerobic
- sinusitis
Introduction
Chronic rhinosinusitis (CRS) is a clinical disorder that encompasses a heterogeneous
group of infections and inflammatory conditions affecting the nose and the paranasal
sinuses.[1]
[2]
[3] Chronic rhinosinusitis is a common disease in otorhinolaryngologic practice worldwide.[2] Antibiotics are prescribed empirically, which could result in treatment failure
and in the development of antimicrobial resistance.[4]
[5]
In 1996, the multidisciplinary Rhinosinusitis Task Force of the American Academy of
Otolaryngologists, Head and Neck Surgeons (AAO-HNS)[6] proposed a clinical diagnosis of CRS as a continuous inflammation of the mucosa
of the nose and of the paranasal sinuses with at least 2 major and 1 minor criteria
or 2 minor and 1 major criteria for at least 12 consecutive weeks.[7] The major criteria include nasal obstruction/blockage, nasal discharge/purulence/discolored
postnasal drainage, hyposmia/anosmia, facial pain/pressure, and purulence in the nasal
cavity on examination. The minor criteria are headache, fever, halitosis, dental pain,
cough and ear pain/pressure/fullness.
The Sinus and Allergy Health Partnership (SAHP)[8] upheld the proposal of the AAO-HNS and put forward that objective evidence of inflammation
must be present and identified in association with the ongoing symptoms. Hence, a
nasal endoscopy and a computed tomography (CT) scan of the paranasal sinuses or a
plain occipitomental (OM) view sinus radiograph should be necessary as means of supporting
the diagnosis of adult CRS.
Bacteria, fungi or viruses may be involved in many cases, but there may be some cases
with no identifiable pathogenic organism. Generally, pathogen-positive cultures are
recovered in 50 to 60% of the patients with CRS.[9]
[10] In Nigeria, while a study in Ilorin[4] showed that 45% of the patients with CRS had pathogenic isolates using a posterior
nasal swab, another study in Sokoto[5] showed that infective causes accounted for 67.1% of the cases of CRS. The study
from Ilorin[4] showed sensitivity to ofloxacin, cefuroxime and resistance to penicillins. Amoxicillin-clavulanate
was also shown to be effective in CRS.
Antibiotics are by far the most commonly prescribed drugs for CRS.[1]
[11] The selection of these antibiotics is usually empirical, sometimes with inadequate
dose and duration of treatment. To treat patients adequately and to prevent the development
of resistance, it is necessary to prescribe the appropriate antimicrobial for the
appropriate duration based on the antibiotic sensitivity of the pathogens involved.
Therefore, the identification of these pathogens should form the basis of prescribing
antibiotics. The present study aims to determine the antibiotic sensitivity pattern
in patients with CRS seen at the study center.
Methods
This was a prospective cross-sectional descriptive study aimed at determining the
sensitivity pattern of bacterial isolates associated with CRS among patients suffering
from this condition. The research was conducted at the study center in the the National
Ear Care Centre from samples collected by endoscopically-guided middle meatal swabs
(Karl Storz, Germany). Ethical clearance was obtained from the institutional Health
Research Ethics Committee (HREC). Middle meatal swabs from 130 patients with CRS were
analyzed microbiologically to determine the common pathogens. The study population
included male and female patients attending the clinic of the study center who met
the diagnostic criteria of CRS according to the multidisciplinary Rhinosinusitis Task
Force of the AAO-HNS[6] as modified by the Sinus and Allergy Health Partnership (SAHP).[8] A plain OM view sinus radiograph of the paranasal sinuses was used for supporting
the diagnosis of CRS. Consecutive patients seen by the researchers in the study center
with diagnosis of CRS from November 2013 to May 2014 who satisfied the inclusion criteria
were recruited.
A structured questionnaire based on the research questions was employed for the present
study. A DARAY HL 550 medical examination headlight (Daray Ltd., Derbyshire, UK) served
as the light source for the physical examination. A Thudicum nasal speculum was used
for anterior rhinoscopy; rigid endoscopes in sizes 2.7 mm and 4 mm, 0° and 30° were
used for nasal endoscopy, and an endoscopically-guided middle meatal swab was used
for the collection of samples. Local anesthesia, vasoconstriction, and decongestion
were achieved with 10% xylocaine spray and 2% lignocaine in adrenalin at 1:200,000
dilution.
A 10-milliliters syringe filled with normal saline solution was then used to irrigate
the nasal cavities, and then a sterile swab stick was used to take the swab from the
middle meatus. The collected swab was inoculated on to the culture media: Chocolate
agar and macConkey agar for aerobic cultures; cooked meat agar and blood agar for
anaerobic cultures.
An oxygen absorbing and carbon-dioxide generating Master Anaerobic GasPak (Micromaster
Laboratories PVT, Maharashtra, India) was used for anaerobic culture, while an Equitron
anaerobic jar (Equitron Medica Private Limited, Mumbai, India) was used for the incubation
and the rearing of anaerobes.
The antibiotic sensitivity test was performed by the diffusion method[12] using a Multidisk maxidisc high profile +ve (Maxicare medical laboratory, Nigeria),
including Peflacine (10 µg), gentamycin (10 µg), Ampiclox (30 µg), Zinacef (20 µg),
Rocephin (25 µg), ciprofloxacin (10 µg), streptomycin (30 µg), Septrin (30 µg), erythromycin
(10 µg), and negative including Septrin (30 µg), chloramphenicol (30 µg), sparfloxacin
(10 µg), ciprofloxacin (10 µg), amoxicillin (30 µg), gentamycin (10 µg), pefloxacin
(30 µg), Tarivid (10 µg) and streptomycin (30 µg). Other single-disc antibiotic-sensitivity
tests included metronidazole and Augmentin. The reading was based on the zone of inhibition
measured in millimeters using a calibrated ruler, using an interpretative chart of
zone sizes according to the antibiotics, and were graded as sensitive (++ + ), intermediate
(++), or resistant.
Results
A total of 130 patients with CRS were studied. The age range was between 18 and 55
years old, with a mean age of 31.87 ± 8.60 years old. The sample consisted of 67 (51.5%)
males and 63 (48.5%) females, with a male to female ratio of 1.1:1, as shown in [Table 1].
Table 1
Age and gender distribution of study group
Group age (years)
|
Gender
|
Total
|
Male
|
Female
|
11–20
|
4
|
13
|
17
|
21–30
|
34
|
17
|
51
|
31–40
|
19
|
25
|
44
|
41–50
|
8
|
8
|
16
|
51–60
|
2
|
−
|
2
|
Total
|
67 (51.5%)
|
63 (48.5%)
|
130 (100%)
|
The history of empirical treatment of the CRS patients with antibiotics in the last
6 months prior to the ear, nose, and throat (ENT) consultation is shown in [Table 2]. About 57% of the patients admitted to the use of antibiotics (mostly Ampiclox and
amoxicillin) before the ENT consultation, as shown in [Table 2]
Table 2
History of antibiotic usage for chronic rhinosinusitis by the patients studied
Types of Antibiotic
|
Frequency
|
Percentage (%)
|
Ampiclox
|
28
|
21.5
|
Amoxicilin
|
23
|
17.7
|
Augmentin
|
11
|
8.5
|
Metronidazole
|
5
|
3.8
|
Ciprofloxacin
|
4
|
3.1
|
Cefuroxime
|
3
|
2.3
|
Total
|
74
|
56.9
|
***Missing System
|
56
|
43.1
|
Total
|
130
|
100.0
|
*** Those without empirical treatment with antibiotics in the last 6 months prior
to the otolaryngology consultation.
[Table 3] shows the distribution of various bacterial isolates. There were 74 (56.92%) positive
bacterial growths among the 130 subjects, out of which 55 (74.32%) were aerobic and
19 (25.68%) were anaerobic. About 18% of these positive bacterial growths yielded
a mixed growth of aerobic and anaerobic isolates. The most common bacterial isolates
were Staphylococcus aureus (35.14%), Haemophilus influenzae (12.16%), Streptococcus viridians (10.81%) and Streptococcus pneumonia 5 (6.76%).
Table 3
Distribution of various isolates in participants
Species
|
Swab specimen of patients
|
Frequency (%)
|
Bacterial isolates
|
(n = 74)
|
Aerobic bacterial isolates
|
|
Gram positive
|
|
Staphylococcus aureus
|
26 (35.14%)
|
Coagulase negative staphylococcus
|
4 (5.41%)
|
Streptococcus viridans
|
8 (10.81%)
|
Streptococcus pneumonia
|
5 (6.76%)
|
Gram negative
|
|
Haemophilus influenzae
|
9 (12.16%)
|
Pseudomonas aeruginosa
|
1 (1.35%)
|
Neisseria specie
|
2 (2.70%)
|
Total aerobic bacteria
|
55 (74.32%)
|
Anaerobic bacterial isolates
|
|
Gram positive
|
|
Peptostreptococcus
|
8 (10.81%)
|
Anaerobic bacillus
|
5(6.76%)
|
Gram negative
|
|
Bacteroides spp
|
6 (8.11%)
|
Total anaerobic bacterial isolates
|
19 (25.68%)
|
Total bacterial isolates
|
74 (100%)
|
[Tables 4] and [5] show the antibiotic sensitivity pattern of the studied bacterial isolates. Augmentin,
ciprofloxacin, and Peflacine were found to be the most effective, with 100% sensitivity,
followed by levofloxacin, Rocephin, erythromycin, and Zinat, in that order, showing
intermediate sensitivity. Most isolates were resistant to Ampiclox, Amoxil and Septrin.
Table 4
Sensitivity pattern of bacterial isolates in chronic rhinosinusitis
Isolates tested
|
Freq
|
Au
|
Cp
|
Pef
|
E
|
R
|
Z
|
Staphylococcus aureus
|
27
|
27s
|
27s
|
27s
|
15s,12i
|
20s,7i
|
15s,12i
|
CONS
|
27
|
27s
|
27s
|
27s
|
12s,15i
|
22s, 5i
|
16s,11i
|
Streptococcus viridians
|
8
|
8s
|
8s
|
8s
|
7i, 1s
|
6s, 2i
|
5s,3i
|
Streptococcus pneumonia
|
5
|
5s
|
5s
|
5s
|
5s
|
4s,1i
|
5s
|
Haemophilus influenzae
|
9
|
9s
|
9s
|
9s
|
9s
|
9s
|
9i
|
Pseudomonas aeruginosa
|
1
|
1s
|
1s
|
1s
|
1r
|
1r
|
1r
|
Neisseria specie
|
3
|
3s
|
3s
|
3s
|
3s
|
3s
|
3s
|
Peptostreptococcus
|
8
|
8s
|
8s
|
8s
|
8r
|
8r
|
8r
|
Anaerobic bacillus
|
5
|
5s
|
5s
|
5s
|
5r
|
5r
|
5r
|
Bacteroides spp
|
6
|
6s
|
6s
|
6s
|
6r
|
6r
|
6r
|
Total
|
99
|
99s
|
99s
|
99s
|
45s,34i,20r
|
64s,15i,20r
|
44s,35i,20r
|
Abbreviations: Au, Augmentin; CONS, coagulase negative staphylococcus species; Cp,
ciprofloxacin; E, erythromycin; i, intermediate sensitivity; Pef, Peflacine; r, resistant;
R, Rocephin; s, sensitive; Z, Zinat.
Table 5
Sensitivity pattern of bacterial isolates in chronic rhinosinusitis
Isolates tested
|
Freq
|
Ax
|
Am
|
S
|
M
|
L
|
Staphylococcus aureus
|
27
|
10i,17r
|
27i
|
10s,17i
|
27i
|
21s,6i
|
CONS
|
27
|
7i, 20r
|
20i, 7r
|
6s,21i
|
27i
|
23s, 4i
|
Streptococcus viridians
|
8
|
4i, 4r
|
8i
|
8i
|
6i,2r
|
6s, 2i
|
Streptococcus pneumonia
|
5
|
3i, 2r
|
4i,1r
|
5i
|
5i
|
4s, 1s
|
Haemophilus influenzae
|
9
|
2i, 7r
|
7i, 2r
|
4i,5r
|
9i
|
7s, 2i
|
Pseudomonas aeruginosa
|
1
|
1r
|
1r
|
1r
|
1s
|
1i
|
Neisseria specie
|
3
|
1i, 2r
|
3s
|
3i
|
3i
|
2s,1i
|
Peptostreptococcus
|
8
|
8r
|
8r
|
8r
|
8s
|
6s, 2i
|
Anaerobic bacillus
|
5
|
5r
|
5r
|
5r
|
5s
|
3s, 2i
|
Bacteroides spp
|
6
|
6r
|
6r
|
6r
|
6s
|
3s, 3i
|
Total
|
99
|
27i, 72r
|
3s, 66i, 30r
|
16s, 58i, 25r
|
20s, 77i, 2r
|
75s, 24i
|
Abbreviations: Am, Amoxil; Ax, Ampiclox; CONS, coagulase negative staphylococcus species;
i, intermediate sensitivity; L, levofloxacin; M, metronidazole; r, resistant; s, sensitive;
S, Septrin.
Discussion
Culture targeted therapy based on the antibiotic sensitivity of the pathogens identified
in patients with CRS remains the gold standard if cure is the primary aim of the treatment.
In the present study, there were 74 (56.92%) bacterial growths, of which 55 (74.32%)
were aerobic, and 19 (25.68%) were anaerobic. This falls within the global average
rate of between 50 and 60% in the recovery of bacterial growth in CRS.[9]
[10] However, this is higher than the findings of Ologe et al in Ilorin, who reported
a prevalence of 45% of bacterial growth in patients with CRS.[4] The difference could be either because only aerobic bacteria were evaluated in that
study or due to a difference in the geopolitical area.
The most common bacterial isolates were S. aureus (35.14%), H. influenzae (12.16%), S. viridians (10.81%) and S. pneumonia 5 (6.76%). These findings are similar to those reported in the study by Araujo et
al,[13] in Brazil, in which S. aureus (31%) was the most common aerobe found. However, it is lower than the prevalence
of 48.1% reported by Ologe et al,[4] who used swabs from the posterior nasal fossa instead of the middle meatal swab
used in the present study.
In the present study, Augmentin, ciprofloxacin and Peflacine were found to be most
effective. Rocephin, levofloxacin, erythromycin and Zinat were effective but not as
effective as the first three. This suggests that levofloxacin may not be as effective
as other quinolones in the treatment of CRS. Therefore, there is a need for further
studies to verify its efficacy in CRS. In the present study, Zinat showed intermediate
sensitivity to most isolates. There was resistance to Ampiclox, Amoxil and Septrin.
The penicillins were similarly found to be least sensitive in a study by Ologe et
al[4] in Ilorin, where ofloxacin had 100% sensitivity. Kamau et al[14] reported that erythromycin, cefadroxil, chloramphenicol and amoxicillin have high
sensitivity, while ampicillin, cotrimoxazole, and pefloxacin had poor sensitivity
in Kenya, showing both comparable and contrasting features with the present study.
This may be due to a difference in the antibiotic resistance pattern in different
geographical regions in the country. The fact that the isolates in the present study
are less susceptible to cephalosporins than to ciprofloxacin, Peflacin and Augmentin
may be due to the anaerobes and gram-negative aerobes, but cross-resistance with penicillins
might be a possibility. This resistance is of public health importance because the
history of antibiotic usage by the patients revealed that ∼ 40% of the patients with
CRS used either Ampiclox or Amoxil prior to the ENT consultation in the present study.
Conclusion
In the present study, Augmentin, ciprofloxacin and Peflacine have 100% sensitivity,
while most of the organisms show resistance to Ampiclox, amoxicillin and Septrin.