When Does Blood Culture Become Necessary for Oral Infections?
The oral physician must indicate blood cultures when radiographic modalities and nuclear imaging techniques, such as radionuclide imaging, indicate chronic infections in the orofacial cavity or the jaw region. The dental or oral surgical operators commonly advocate this because, although radiography would show the extent of the pathology, oral pathologists must first identify the primary causative organism causing the dental or systemic infection. This is made possible by the development of modern three-dimensional technology, such as CBCT (cone beam computed tomography) and multidetector CT (computed tomography) scans, or even by PET (positron emission tomography) scans, bone scintigraphy, etc.
This brings us to the necessity of initiating a blood culture or exudate test, especially when the general or oral physician suspects most chronic infections, either bacteremia (bacteria entering the bloodstream causing bloodstream infections) or septicemia (bacteria entering the bloodstream causing systemic infections). Some common bacteremia or septicemia-causing pathogens in the orofacial cavity are Streptococci, Staphylococci, or Pneumococci.
For example, the classic cases of osteomyelitis (bone inflammation) of the jaw with multiple scattered mandibular (lower jaw) lesions usually reveal blood cultures of streptococcal infections that result in the causative for septicemia.
Hence, many such underlying or immunocompromising infections can be revealed, primarily to determine the aerobic or anaerobic nature, the potential, and the inflicting capacity of the bacterial, viral, or fungal pathogens through blood culture. Generally, oral pathologists recommend that in the case of chronic infections, at least one ounce of blood should be obtained from the affected or suspected patient indicated for the blood culture test, while in the case of acute infections, around 0.16 ounces of blood is indicated. A blood sample from one of the patients would be adequate.
What Are the Common Culture Tests in Dentistry and Maxillofacial Surgery?
Let us examine what the blood or exudate culture of common jaw and orofacial infections looks like:
Examination of the Exudates in Actinomycosis Infections:
In a blood culture test, when actinomyces infections need to be confirmed, the discharge that would be pressed out from the fistula in the patient's oral cavity or jaw would typically comprise the sulfur granules. Also, when these granules are soft, they can be easily pressed by the oral pathologists or the technician between the two slides before the histopathologic examination (slide preparation). These can be subsequently examined even without staining. The granules in Actinomyces infections usually appear like rosette masses with dense centers histopathologically, with a characteristic mycelium network. Further, many bulbous clubs extend from the lesions' periphery, confirming the diagnosis of actinomyces jaw infections.
Blood Culture for Candida Albicans:
Oral pathologists usually use moist preparations when oral thrush or primary/secondary orofacial infection with the fungal species of Candida albicans is suspected. The scrapings from the patient's sample, the alleged lesion, are usually directly placed on a microscopic slide alongside a 10 percent potassium hydroxide solution. The pathologist then heats the slide slightly and inspects the sample under the microscope. The slide is typically examined to confirm the branching mycelia and spores of Candida albicans, which, when present, clearly indicate the fungal infection.
Examination of the Cystic Fluid Contents:
Most orofacial or dental cysts usually comprise a fluid or semi-fluid material. These are best used for diagnostic purposes because they can be easily aspirated for culture using a glass syringe and a basic hypodermic needle. The operating dental surgeon thoroughly prepares the anesthetized segment or the lesion spot where the needle is inserted or the bone is to be perforated with the help of a sterilizing agent. The affected area is then isolated with sterile gauze. The cystic content from the lesions would be aspirated and examined on the prepared slide or culture medium. This gives a clear insight into the nature of the cyst and can provide the oral pathologist with a confirmative or final diagnosis of the specific type of dental or orofacial cyst.
Bacteriologic Tests of Pulp Canals:
The common culture technique from dental pulp canals that are suspected of causing bacteremia or septicemia (uncontrolled endodontic or extensive cavitated infections) is as follows:
The dentist or the endodontist primarily first dries up the root canal with sterile absorbent points. After using these points, the operator usually ensures that the tip is moistened by the pulpal or root canal exudate for around one minute.
On the other hand, the tip is removed with the help of cotton pliers, and with the test tube, the operator carefully isolates the sample from the patient's dental pulp. This is beneficial to detect pulpal anaerobes or pathogens that may be causing bacterial infections of the head and neck, especially in uncontrolled and dentally non-treated cases.
Examination or Culture of Exudates From Inflammatory Lesions:
This is usually done from the oral soft tissues or gingival pockets (abnormal deepening of the gingiva surrounding the tooth), where inflammatory soft tissue lesions commonly manifest. While the discharge from a common gingival abscess (pus forms in the gum tissue), for instance, contains a variety of pyogenic bacteria, including Streptococcus pyogenes, Pneumococcus species, and Staphylococcus, the discharge from chronic high-grade infections, like fistulae, dental or orofacial antrulas, or cysts, typically shows a higher number of leukocytes or white blood cells. Plaque deposits can similarly be used to analyze tooth surface lesions.
Conclusion:
In all the above situations, the laboratory that examines the culture sample must always strictly adhere to proper transport, disinfection, and correct examination methods. The laboratory technician must follow several protocols while handling the culture or the exudate sample to ensure that the oral pathologist receives the ideal sample for examination.
Blood culture and exudate tests for oral microorganisms have the potential to prevent life-threatening bacteremia or septicemia caused by undesirable systemically involving pathogens affecting dentition or oral cavity by properly labeling patient oral specimens, preventing cross-contamination during shipping or while handling the sample until it reaches the laboratory from the dental clinic or the hospital setting, and using an adequate amount of fixative or preservative to prevent sample contamination before examination. These protocols are crucial in today's blood culture examination to ensure that the maxillofacial or oral surgeon makes the correct diagnosis.
