Khartoum Medical Journal (2008) Vol. 01, No. 03, pp. 129 - 132 129
Correlation between surface swab
culture and tonsillar core culture in
patients with recurrent tonsillitis
Motassim Al-Roosan, Nemer Al-Khtoum*, Hussein Al-Said
االرتباط بني زراعة املسحة السطحيّة وزراعة لب اللوزة في مرضى التهاب اللوزتني املتكرّر
ِ ِ ِ ِ
.الهدف: تقرير االرتباط بني زراعة املسحة السطحية وزراعة لب اللوزة في مرضى التهاب اللوزتني املتكرر
ّ ِ ِ ِ ّ ِ ِ ْ
.املرضى والطرق: متت دراس��ة مائة مريض من كال اجلنس��ني فوق عمر 3 سنوات الذين تقرر لهم استئصال اللوزتني
.كان هناك 83 أنثى و26 ذكر بني أعمار 3 -53 سنة. متت زراعة عينات من كال السطح ولب اللوز
النتائج: في 63 حالة، مت عزل مسببات مرضية بزراعة لب اللوزة لكن لَيس بزراعة املسحة السطحية. في 24 حالة
ِ ِ َ
مس��ببات مرضية دقيقة مت عزلها بزراعة لب اللوزة، تختلف عن البكتيريا الس��طحية. تناقض بني زراعة املس��حة
الس��طحية وزراعة لب اللوزة بالنس��بة إلى وجود أَو غياب املسببات املرضية ا للبية كان في 26 حالة )26 %( بينما
.(% 38) كان مماثالً في 83 حالة
في 02 حالة )02 %( ا ملسببات املرضية كانت موجودة على زراعة املسحة السطحية بينما زراعة لب اللوزة كانت
.طبيعية. 41 حالة )41 %( من اجملموعة الدراسية أظهرت جراثيم طبيعية
املسببات املرضية الرئيسية التي مت عزلها من كال املسحة السطحية ولب اللوزة كانت املكورة العنقودية البرتقالية
بيتا املكورة االنحاللية. املكورة ذات الرئة، إنفلونزا اجملزأة احملبة للدم، اجلراثيم العصوية واملكورةA يليها مجموعة
اخلامتة: تش��ير الدراسة بأن زراعة املس��حة البلعومية ال ت َعكس وجود األسباب املرضية بشكل موثوق في لب لوزة
احللق. س��طح لوزة احللق يعكس بشكل رئيسي جراثيم طبيعية في احللق، بينما لب لوزة احللق يظهر منو الكائنات
.احلية التي نادرا ً ما تظهر في زراعة املسحة السطحية
Objective: To determine the correlation between surface culture swab and culture of tonsillar core in patients
with recurrent tonsillitis.
Patients and Methods: One hundred patients booked for elective tonsillectomy were studied. There were 38
females and 62 males between the ages of 3 and 35 years. Specimens from both surface and core of tonsils
Results: Pathogens were isolated by core culture but not by the surface culture in 36 cases. In 42 cases
pathogenic micro flora were identified from the core of tonsils differing from the surface bacteria. Discrepancy
between surface and core culture as to the presence or absence of core pathogens was in 62 cases (62%) while
it was identical in 38 cases (38%). In 20 cases (20%) pathogenic microflora was present on surface culture with
normal core flora. 14 cases (14%) of the study group showed normal flora.
The principal isolate from both the tonsillar surface and core were Staphylococcus aureus followed by Group A
beta hemolytic streptococci, S. pneumonia, Haemophilus influenza, Escherichia coli, Pseudomonas aeruginosa
and S. viridans.
Conclusion: The study indicates that pharyngeal swab cultures do not reliably reflect the presence of pathogens
in the tonsil core. The tonsil surface reflected mainly the normal flora of the oropharynx, whereas tonsil core
showed growth of organisms like Hemophilus and Staph aureus, which were rarely reflected in the surface
Introduction may occur in great numbers. A high tissue concentration
of these bacteria correlates with clinical parameters of
Acute tonsillitis is a common disease. Repeated antibiotic infection and hyperplasia of the tonsils(2).
treatment may fail leading to tonsillectomy. Superficial
swab cultures do not sufficiently represent the core The diagnostic test of swabbing the surface of the
tonsil as a culture specimen for the determination of
the organism responsible for the tonsil infection is
In recurrent tonsillitis, the tonsil core harbours still in practice despite controversy (3).
numerous bacteria, some of which are pathogenic and In many cases, pathogenic organisms were found in
*Corresponding author: PO Box 1834 Amman 11910 the tonsil core, despite the fact that surface cultures
Jordan. revealed only normal respiratory flora(4). Differences
130 Motassim Al-Roosan, Nemer Al-Khtoum*, Hussein Al-Said
between tonsil surface and core bacterial flora may during the 3 weeks prior to tonsillectomy.
explain the increasing failure rate in the eradication After the patient was intubated a tonsillar surface
of the infection from the tonsil particularly by the swab was obtained by rotating a sterile cotton wool
penicillin group of antibiotics leading to chronic stage, swab over the surface of the tonsil not touching other
therefore the rationale of treating chronic tonsillitis parts of the oropharynx. Following this, tonsillectomy
medically should be based on the knowledge of the was performed by dissection technique. Immediately
common core pathogen(5). after excision, the tonsil was immersed in povidine-
Identifying the bacterial organism within the infected iodine solution for 30 seconds. Then it was thoroughly
tonsil for appropriate antibiotic therapy could rinsed with sterile saline, placed in sterile tray and
revolutionize the management of chronic tonsillitis(6). sectioned into two pieces with the help of sterile
The aim of the present study was to determine the scalpel under strict aseptic condition. The same
correlation between surface culture swab and culture procedure of rubbing a sterile swab was applied to the
of tonsillar core. core of the excised tonsils avoiding its outer surface.
Paired samples from individual patients were put in
Material and Methods
the thioglycollate broth immediately for transport to
This study was conducted in the Department of
the laboratory. In the laboratory the specimens were
Otorhinolaryngology, Princess Haya hospital
cultured on 5% sheep blood agar, chocolate agar and
(Aqaba-Jordan). After institutional ethical committee
in Robertson cooked meat medium. The plates were
clearance and written informed consent, one hundred
incubated at 37°C in the presence of 5-10% CO for
patients of both sexes above 3 years of age booked
24-48 h. All the isolates were identified by standard
for elective tonsillectomy were studied. The group
included 38 females and 62 males between the age of
3 and 35 years.
The indication for tonsillectomy was recurrent
tonsillitis defined as at least five attacks of acute Results of cultures from both the surface and the
inflammation of the tonsil during a single year. Recent core of tonsils were compared. A large percentage
upper respiratory tract infection was ruled out. The of the patients had no correlation between organisms
diagnosis was made on the basis of history of recurrent cultured simultaneously from the two sites. See Table
attacks of sore throat, odynophagia and pyrexia. On 1 below.
physical examination, the patients revealed erythema
and debris in tonsil crypts with palpable juglo-digastric
lymph nodes. The patients received no antibiotics
Table 1: Comparison between surface and core cultures in 100 cases
Surface culture Core culture No. of cases
Normal flora Pathogen present 36
Pathogen present Pathogen present (same) 24
Pathogen present Pathogen present (different) 6
Pathogen present Normal flora 20
Normal flora Normal flora 14
In a large group constituting 36 cases, pathogens were cultures.
isolated by the core culture but not by the surface The principal isolate from both the tonsillar surface
culture, thus surface culture did not reliably reflect and core were Staphylococcus aureus followed
the core pathogens. In 42 cases pathogenic microflora by Group A beta haemolytic streptococci, S.
were identified from the core of tonsil, differing from pneumonie, Haemophilus influenza, Escherichia coli,
the surface bacteria. Pseudomonas aeruginosa and S. viridans. See Table
Discrepancy between surface and core culture as to 2.
the presence or absence of core pathogens was in 62
cases (62%) while in 38 cases (38%) it was identical.
Therefore, one should question the value of the surface
culture in predicting the real pathogens in recurrent
In 20 cases (20%) pathogenic microflora were present
on surface culture with normal core flora. 14 cases
(14%) of the study group showed normal flora in both
Correlation between surface swab culture and tonsillar core culture in patients with recurrent tonsillitis 131
Table 2: Pathogenic microflora isolated from the tonsils in 100 cases
Pathogenic microflora Tonsillar surface Tonsillar core
Staphylococcus aureus 14 20
Group A beta haemolytic streptococci 12 18
S. pneumonia 10 14
Haemophilus influenza 2 6
Escherichia coli 4 2
Pseudomonas aeruginosa 2 2
S. viridans 2 0
In core cultures, staphylococcus aureus was the most and Haemophilus sp.
common pathogen. Another important organism In the present study in a large group constituting 36
found in core culture, which was rarely predicated in cases, pathogens were isolated by the core culture but
surface culture was Hemophilus influenze. Four cases not by the surface culture. Similar observations were
of polymicrobial infection were encountered in the noted in other studies (4).
study. In these cases the causative agent was S. aureus Overall surface culture was in variance as to the
and beta haemolytic streptococci. presence or absence of core pathogens in 62 cases
(62%). Similarly, Rosen et al(15) found 48% variance
Discussion between surface and core micro-organisms.
The pathogenesis of recurrent tonsillitis is largely These findings may explain recurrence of tonsillitis
unknown. Selection of appropriate antibiotic therapy and makes the reliability of the conventional tonsillar
for patients with recurrent tonsillitis is difficult because culture questionable. Surgical extirpation of the tonsils
of the limitations of traditional methods of sampling seems to be the only treatment since deep bacteria
tonsillar microflora and the increasing incidence of remain unidentified and resist the antibiotic therapy
beta-lactamase producing bacteria in the tonsil(7). that may affect only the surface microflora.
In the present study, the commonest indication for
tonsillectomy was recurrent tonsillitis. The current Conclusion
widely accepted criteria for surgery are of the order of The study indicates that pharyngeal swab cultures do
seven episodes of tonsillitis in the preceding year, five not reliably reflect the presence of pathogens in the
episodes in each of the preceding two years or three tonsil core. Routine culture of the throat by surface
episodes in each of the preceding three years, these swab for the accurate diagnosis of bacterial flora in
were arrived at arbitrarily(8,9). chronic tonsillitis is neither reliable nor valid.
There is near unanimity regarding this indication The tonsil surface reflected mainly the normal flora of
among various authors(10,11). Cable et al(12) found no the oropharynx, whereas tonsil core showed growth of
correlation between the size of the tonsils and the organisms like Hemophilus and Staph aureus which
indication for tonsillectomy. Barr et al(11) echoed a were rarely reflected in the surface culture.
similar view. References
In our study, the tonsillar surface and core culture 1. Inci E, Karakullukcu B, Aygun G, Yasar H,
swabs showed S. aureus in 14 and 20 cases, while Enver O, Yagiz C. Fine-needle aspiration as
Group A beta haemolytic streptococci was found in a diagnostic tool for recurrent tonsillitis. J Int
12 and 18cases. These findings were comparable to Med Res 2003; 4:307-11
the findings of Ozek et al(13) who identified S. aureus 2. Lindroos R. Bacteriology of the tonsil core in
in 33% and beta haemolytic streptococci in 30% recurrent tonsillitis and tonsillar hyperplasia--
isolates. a short review. Acta Otolaryngol Suppl 2000;
In a study by Surow et al(4), the tonsils of 97 543:206-8.
children undergoing tonsillectomy were studied to 3. Kurien M, Stanis A, Job A, Brahmadathan,
determine the correlation between surface culture Thomas K. Throat swab in the chronic
swab and culture of tonsillar core, Staphylococcus tonsillitis: how reliable and valid is it?
was the most common isolate from both surface Singapore Med J 2000 Jul; 41:324-6.
and core. 4. Surow JB, Handler SD, Telian SA, Fleisher
In the study by Brook et al(14) specimens from both GR, Baranak CC. Bacteriology of tonsil
the surface and the core of tonsils from 23 children surface and core in children. Laryngoscope
with recurrent tonsillitis were cultured for aerobic 1989; 99:261-6.
and anaerobic microorganisms. The predominant 5. Kindo AJ, Somu L, Srikanth P, Varadrajan M,
aerobic isolates were alpha-hemolytic streptococci, Lakshmanan K. Role of surface swab, core
Staphylococcus aureus, beta-hemolytic streptococci, swab and fine needle aspiration in isolating
132 Motassim Al-Roosan, Nemer Al-Khtoum*, Hussein Al-Said
the core bacteria in inflammed tonsils. Indian
J Pathol Microbiol 2001; 44:293-5.
6. Kurien M, Sheelan S, Jeyaseelan L,
Bramhadathan, Thomas K. Fine needle
aspiration in chronic tonsillitis: reliable and
valid diagnostic test. J Laryngol Otol 2003;
7. Gaffney RJ, Cafferkey MT. Bacteriology of
normal and diseased tonsils assessed by fine-
needle aspiration: Haemophilus influenzae
and the pathogenesis of recurrent acute
tonsillitis. Clin Otolaryngol Allied Sci 1998;
8. Donnelly MJ, Quraishi MS, Shane MC.
Indications for paediatric tonsillectomy GP
versus Consultant perspective. J Laryngol
Otol 1994; 108:131-4.
9. Paradise JL, Bluestone CD, Bachman R, et al.
Efficacy of tonsillectomy for recurrent throat
infection in severely affected children. N Engl
J Med 1984; 310:674-83.
10. Thomas R. Discussion: is the removal of
tonsils and adenoids necessary? J R Soc Med
11. Geoffrey SB, Iain CK. Comparison of size
of tonsils in children with recurrent tonsillitis
and in controls. BMJ 1989; 298:804.
12. Cable HR, Batch AG, Stevens DJ. The
relevance of physical signs in recurrent
tonsillitis in children. J Laryngol Otol 1986;
13. Ozek O, Egilmcz S, Ang O, Savas I. A
bacteriologic study of chronic tonsillitis. Acta
OtoLaryngologica 1967; 63:455-61.
14. Brook I, Yocum P, Shah K. Surface v/s
core tonsillar aerobic and anaerobic flora in
recurrent tonsillitis. JAMA 1980; 244:1696-8.
15. Rosen G, Samuel J, Vered I. Surface tonsillar
microflora versus deep tonsillar microflora in
recurrent tonsillitis. J Laryngol Otol 1977;