Incidence of Bacteremia and Antibiotic Sensitivity Associated with Oral Surgical Procedures

Incidence of Bacteremia and Antibiotic Sensitivity Associated with Oral Surgical Procedures
Shazia Akbar Ansari 1 , Rakhshanda Baqai 2 , Hassan Mehdi3 , Ghulam Sughra Sahito4 , Gulnaz Ali 5

How to CITE:

Ansari SA, Baqai R, Mehdi H, Sahito GS, Ali G. Incidence of bacteremia and antibiotic sensitivity associated with oral surgical procedures. J Pak Dent Assoc. 2012;21(4):228-234.


The objectives of this research were to evaluate the incidence of bacteremia associated with oral surgical and invasive procedures and determine the antibiotic sensitivity pattern.


A Total of 250 patients between 20 to 50 years of age were selected for this study who underwent different oral and maxillofacial surgical procedures for treatment of dental or periodontal disease. Clinical history was recorded from these patients. Blood samples were collected in blood cultures bottles with Tryptic Soy Broth (TSB) and incubated at 37°C for 7 days. After incubation sub culturing was done on a suitable media for bacterial growth and plates were incubated for 24-48 hours at 37°C. Colonies were identified by colony morphology, gram’s staining and standard biochemical tests. Antibiotic sensitivity was done by disc diffusion method.


Bacteremia was detected in 90 % of cases most commonly affecting the females. Tooth extraction (55%) was major cause of bacteremia. Major isolates were Staphylococcus aureus 56%, Escherichia .coli 25%, Pseudomonas aeruginosa 13%, Salmonella typhi 4% and Shigella spp.2%. Antibiotic sensitivity test revealed that all microbial isolates were sensitive to commonly used antibiotics.


Majority of the patients have post treatment bacteremia. Female gender and Tooth extraction, were associated with increased incidence of bacteremia. Most of the antibiotics were sensitive for different microorganisms isolated from oral surgical procedure.


Bacteremia, Antibiotic resistance, oral surgical procedures


Dental diseases are caused by microorganisms in the mature plaque and are part of the oral flora1 .Gingivitis, periodontitis, dental caries, pulpitis, pulp necrosis, peripheral abscess, cellulites and pericoronitis are the most common dental diseases2.

Bacteremia can be defined as presence of possible bacteria in the blood circulation,sup>3 . Invasive oral surgical and dental procedures favor the bacterial transmission into the blood stream, causing transient bacteremia. Transient bacteremia can not be eluded, but its possible complications can be avoided by controlling the severity, time duration of bacteremia in blood stream, patient’s tendency with un¬derlying diseases, and susceptible site of infection4. The bacteria that gets access to the blood circulation throughout the body can be removed by the host reticuloendothelial system with in few minutes. In patients with history of cardiac disease, bacteremia can be a potential cause of infective endocarditis, myocardial or cerebral infection. Brain abscess and implantitis related to oral and other micro biota are other common sequel of infections5. Bacteremia may be caused by different conservative dental procedures like fillings or root canal6. After different dental procedures wide range of bacteria have been isolated from blood cultures of patients. Bacteremia was most likely associated with treatment of diseases like gingivitis or periodontitis7. Extractions are the most likely cause of bacteremia. The incidence, nature, and duration (IND) of bacteremia are mainly enhanced by the increased invasion8. After dental procedures the oral bacteremia is rare in children9 However, a study reported an incidence of bacteremia as high as 65% in children.10,11,12

The isolation of micro-organisms sharply decreased between 10 and 30 minutes after invasive oral surgical and dental procedures13. After dental treatment, the impact of prophylactic antibiotic on the IND of bacteremia is controversial 14,15,16.

Distribution of oral microbes into the blood circulation is very common, even within few seconds after an oral or dental procedure, microbes from the site of infection may reach the lungs, heart, and peripheral circulation17. With good oral hygiene and dental care, only small numbers of facultative bacteria gain entrance to the circulating blood. With improper oral hygiene, the large numbers of bacteria colonizing the teeth and other surfaces, thus possibly introduce increased number of bacterias into tissues and can increase the prevalence and magnitude of bacteremia,sup>18.

The objectives of this study were to evaluate the incidence of bacteremia associated with various oral and maxillofacial surgical procedures and we will determine the antibiotic sensitivity pattern in a sample Pakistani population.

Material and Methods

A total of 250 patients between 20 to 50 years of age undergoing oral and maxillofacial surgical procedures at Fatima Jinnah Dental College and Hospital Karachi between July 2007 to December 2008 were selected for this study. Use of systemic or local antibiotics within the previous 15 days, use of prophylaxis antibiotic according to current practice guidelines, history of active viral disease, Immunocompromised patients, uncontrolled systemic disease and conditions, penicillin allergy, facial cellulitis and advanced age were exclusion criteria. The study was approved by the Ethical Committee of Fatima Jinnah Dental College & hospital Karachi. All participating individuals completed a questionnaire including personal data and medical history. Informed consent was taken from every patient after introducing study protocol.

Dental and periodontal disease parameters included mean periodontal pocket depths, calculus scores (range 0 to 3), and periodontal status was assessed according to the WHO Community Index for Periodontal treatment Need (CPITN). Basic oral health status of all patients was evaluated using DMFT (decayed, missing, filled teeth). Dental plaque accumulation, gingivitis, gingival bleeding and the dental abscess were recorded and their relationship to bacteremia was assessed with poor oral hygiene. 1.8ml of 2% lidocaine with 1:100 000 epinephrine was injected 15 minutes before surgery. The procedures were performed under local anesthesia included surgical dental extractions, scaling, impaction removal, cyst enucleation, alveoloplasty and apicectomies. Blood samples were collected for bacteriological examination immediately after the essential steps of the oral surgical procedures had been performed. Thirty blood samples were collected to determine the frequency of bacteremia before the surgical procedures (baseline bacteremia), 5ml of blood was obtained after the administration of local anesthesia. Samples of venous blood were collected from the antecubital vein of each patient using 18-22 G sterile needle with disposable syringe after the site was scrubbed with alcohol. Blood sample was inoculated in the blood culture bottles filled with 20ml Tryptic Soya broth and incubated at 37°C for 7 days.

Subculturing was done on blood agar and MacConkey’s agar. The plates were incubated at 37°C aerobically for 24-48 hours after which growth was observed. Colonial morphology was observed on blood agar and MacConkey’s agar plates. Morphologically different colonies were stained by Gram’s staining and identified by different biochemical tests. Antibiotic susceptibility test was performed by disc diffusion technique on isosensitivity agar according to the clinical laboratory Standard Institute (CLSI) guidelines. Penicillins: ampicillin (10mcg), amoxycillin (20mcg), cephalosporins: cephalexin (30 mcg), cefotaxime (30mcg), ceftazidime (30mcg), ceftizoxime (30mcg), Aminoglycosides: gentamicin (10 mcg), tetracyclines: doxycycline (30mcg) and chloramphenicol (30 mcg) were used to determine the antibiotic resistance. Plates were incubated at 37°C for 24 hours. The diameter of the zone of inhibition were measured to determine the susceptibility of antibiotic.


A total of 250 dental patients undergoing different dental and oral surgical procedures were included in this study. There were (118) 47% males and (132) 53% females. Only one out of the 30 blood samples obtained before the start of surgery was positive for bacteremia,

Fig. 1 indicates the distribution of dental patients according to age and gender. Dental infections were found to be more common in females between the age group of 20-29 years and 40-49 years. WHO Community Index for Periodontal treatment Need (CPITN) was used to assessed dental and periodontal disease status. Dental plaque deposits, gingivitis, spontaneous gingival bleeding and the periodontal pockets depth were recorded for evaluation of dental health.

Fig. 2 shows Basic oral health status of all patients that was obtained by using CPITN (community periodontal indices treatment need), Calculus was found in 215 patients (86%), pockets were between 4-5mm in 195 (78%), bleeding in 128 (51.2%) and 6mm or more pockets were present in 46 patients (18.6%) due to poor oral hygiene.

Fig. 3 indicates the incidence of bacteremia associated with different oral surgical procedures. Bacteremia was most commonly found after dental extraction(122) 49%, dental scaling can cause (91)38% and endodontic treatment can induce (37) 13% bacteremia.

Fig.4 indicates the bacterial growth in blood samples obtained from patients undergoing oral surgical procedures. 90% blood samples were positive for bacterial growth only 10% samples were negative for microbial growth as few samples were taken before surgical procedures to determine baseline bacteremia. The blood samples were obtained within 10 minutes after the surgical procedures so there are high chances of transient bacteremia.

Figure. 5 indicates frequency of the bacterial isolates from blood cultures associated with oral surgical procedures. S.aureus 56%, E.coli 25%, Pseudomonas spp.13%, S.typhi 4% and Shigella spp. 2% were major isolates. Antibiotic sensitivity tests were done by disc diffusion technique on isosensitivity agar and performed according to the clinical laboratory Standard Institute (CLSI) guidelines.

Figure 6. Indicates the antibiotic sensitivity pattern of S.aureus against different antibiotics. Ampicillin sensitivity was (98%), clindamycin (79%), vancomycin (77%), tetracycline (77%), cephalexin (71%), and cefoxime (47%) sensitive.

Figure 7. Shows the antibiotic sensitivity pattern of E.coli against different antibiotics. E.coli was sensitive to ciprofloxacin (46%), tetracycline (37%), cephalexime (33%), gentamycin (29%) and ceftazidin (28%).

Figure 8. indicates the sensitivity pattern of Pseudomonas spp. against different antibiotics. Pseudomonas spp. (24%) were sensitive to tetracycline, gentamycin (20%), cephalexin(20%) and ceftazidin (19%).


Dental infections are often reported in our country. Microorganisms are part of normal flora and can be a cause of a variety of dental infections and periodontal diseases. Various conservative and surgical procedures can result in significant bleeding which leads to bacteremia19. Oral surgical procedures can cause the spread of bacteria into the blood stream during dental treatments20. In this study, only one patient had a positive blood culture before the oral surgical procedure. This low baseline incidence would therefore support the argument of the surgical procedure being the cause of any consequent bacteremia. Bacteremia can be significantly reduced with proper sterilization techniques and improved instrumentation21,22. In the present study females between the age of 20-29 years and 40-49 years had more incidence of bacteremia associated with oral surgical procedures. In the present study Calculus was present in 215 (86%) patients, pockets were measured between 4-5mm in 195 (78%) patients, bleeding on probing was present in 128 patients (51.2%) and 6mm or more pockets were observed in 46(18.4%) patients.

The incidence of bacteremia has been well documented with different dental procedures such as extraction of a tooth, conservative management, periodontal treatment, root planning and scaling23,24. In another study 100% bacteremia was observed in patients after dental extraction, 70% after dental scaling, 55% after surgery of third-molar, 20% after conservative management and 55% after bilateral tonsillectomy. Another study on 735 children undergoing treatment for extensive dental decay reported 9% of the children with bacteremia before oral and dental procedures. Some what similar results were found in our study. We observed (131) 52% bacteremia after dental extraction which was the major cause of bacteremia.

Bacteremia also results from different conservative and dental procedures. Like placements of matrix band and rubber dam placement have caused bacteremia in patients during dental treatment26. In the present study we observed (102) 42% bacteremia after dental scaling and (15) 6% bacteremia after endodontic treatment. Local anesthetic injection by normal buccal infiltration technique has been reported to cause bacteremia in 16% of children27. In this study only 10 % blood samples were negative for bacterial growth as few samples were taken to detect the base line bacteremia before the surgical procedures and 90% patient had bacteremia after oral surgical procedures. In this study bacterial isolates from blood cultures were S.aureus 58%, E.coli 25%, Pseudomonas spp. 13%, S.typhi 4% and Shigella spp. 2% .Other reports indicates a high frequency of Staphylococci with infective endocarditis and other conditions28. Our research is most likely similar to other reported findings as the tooth extraction is the most common cause of bacteremia and the major isolates resemble with other studies.

Endodontic infections are usually mixed micro biota with a predominance of anaerobic bacteria and P. aeruginosa which is in accordance with previous study29. In asymptomatic endodontic infections the micro biota was facultative anaerobic and aerobic30. In the presence of caries and periodontitis the microorganism which reaches the pulpal and periapical tissue causes pulpitis or periapical periodontitis. In these cases even the administration of prophylactic antibiotics does not drastically reduce the incidence or degree of bacteremia after tooth removal31. It is highly recommended that patients with pre-existing high-risk heart disorders undergoing different dental or oral surgical procedures must be treated with prophylactic antibiotics32. A single dose of prophylactic antibiotic should be given but when the procedure takes more than two hours, another dose should be administered. In patients with history of allergy to β-lactamase, clindamycin or clarithromycin is recommended33. Most common cause of bacteremia is dental extractions. Simple tooth brushing may affect the surface area of gingival crevicular tissue that may be a cause of bacteremia but the nature and incidence of bacteremia are not same as a dental extraction, and the risk of bacteremia with tooth brushing is similar to dental extraction34.

Bacteremia can not be avoided, but its possible complications can be evaded by controlling the severity, time duration of bacteremia in blood stream, patient’s tendency with un¬derlying diseases and susceptible site of infections.


1. Bacteremia was detected in majority of patients undergoing different oral surgical procedures but it was transient in nature.
2. Bacteremia was found to be more common in females between the age group of 20-29 years and 40- 49 years.
3. Dental extractions were found to be a major cause of bacteremia when compared with other oral surgical procedures.
4. Most of the antibiotics were sensitive for different micro-organisms isolated from oral surgical procedures.


Simple infection control precautions, use of protective barriers like mask and gloves, proper sterilization of instruments, proper care of dental unit water supply, good oral hygiene and proper hand washing technique will reduce the incidence of bacteremia before and after the oral surgical procedures. Its recommended prophylactic antibiotics should be administered in patients with a history of congenital or acquired disorders undergoing tooth extraction and invasive dental treatment.


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