Bacteroides is a genus of Gram-negative, obligate anaerobic bacteria. Bacteroides species are non endospore-forming bacilli, may be either motile or nonmotile, depending on the species; the DNA base composition is 40–48% GC. Unusual in bacterial organisms, Bacteroides membranes contain sphingolipids, they contain meso-diaminopimelic acid in their peptidoglycan layer. Bacteroides species are mutualistic, making up the most substantial portion of the mammalian gastrointestinal microbiota, where they play a fundamental role in processing of complex molecules to simpler ones in the host intestine; as many as 1010–1011 cells per gram of human feces have been reported. They can use simple sugars. Studies indicate that long-term diet is associated with the gut microbiome composition—those who eat plenty of protein and animal fats have predominantly Bacteroides bacteria, while for those who consume more carbohydrates the Prevotella species dominate. One of the most important clinically is Bacteroides fragilis.
Bacteroides melaninogenicus has been reclassified and split into Prevotella melaninogenica and Prevotella intermedia. Bacteroides species benefit their host by excluding potential pathogens from colonizing the gut; some species are opportunistic human pathogens, causing infections of the peritoneal cavity, gastrointestinal surgery, appendicitis via abscess formation, inhibiting phagocytosis, inactivating beta-lactam antibiotics. Although Bacteroides species are anaerobic, they are transiently aerotolerant and thus can survive in the abdominal cavity. In general, Bacteroides are resistant to a wide variety of antibiotics—β-lactams and many species have acquired resistance to erythromycin and tetracycline; this high level of antibiotic resistance has prompted concerns that Bacteroides species may become a reservoir for resistance in other, more pathogenic bacterial strains. It is susceptible to clindamycin. An alternative fecal indicator organism, has been suggested because they make up a significant portion of the fecal bacterial population, have a high degree of host specificity that reflects differences in the digestive system of the host animal Over the past decade, real-time polymerase chain reaction methods have been used to detect the presence of various microbial pathogens through the amplification of specific DNA sequences without culturing bacteria.
One study has measured the amount of Bacteroides by using qPCR to quantify the host-specific 16S rRNA genetic marker. This technique allows quantification of genetic markers that are specific to the host of the bacteria Bacteroides and allow detection of recent contamination. A recent report found temperature plays a major role in the amount of time the bacteria will persist in the environment, the life span increases with colder temperatures. Early research suggests. "A new study has found that there is a three-way relationship between a type of gut bacteria and brain metabolites. This relationship, the researchers hypothesize, may lead to further insight into autism, but more in-depth studies are needed." Bacteroides species' main source of energy is fermentation of a wide range of sugar derivatives from plant material. These compounds are common in the human colon and are toxic. Bacteroides converts these sugars to fermentation products. Bacteroides have the ability to remove side chains from bile acids, thus returning bile acids to the hepatic circulation.
There is data suggesting that members of Bacteroides affect the obese phenotype in humans. In this article, one human twin is obese; when their fecal microbiota is transplanted into germ-free mice, the phenotype in the mouse model corresponds to that in humans. Although breast-fed infants do not show appreciable numbers in their stool until after they are weaned, Bacteroides spp. are part of the normal, healthy placental microbiome. CrAssphage Cytophaga Flavobacterium Bacteroides infections in E Medicine Bacteroides in detail
Peptostreptococcus is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small and can occur in short chains, in pairs or individually, they move using cilia. Peptostreptococcus are slow-growing bacteria with increasing resistance to antimicrobial drugs. Peptostreptococcus is a normal inhabitant of the healthy lower reproductive tract of women. Peptostreptococcus species are commensal organisms in humans, living predominantly in the mouth, gastrointestinal and urinary tracts, are members of the gut microbiota. Under immunosuppressed or traumatic conditions these organisms can become pathogenic, as well as septicemic, harming their host. Peptostreptococcus can cause brain, liver and lung abscesses, as well as generalized necrotizing soft tissue infections, they participate in mixed anaerobic infections, a term, used to describe infections that are caused by multiple bacteria that do not require or may be harmed by oxygen. Peptostreptococcus species are susceptible to beta-lactam antibiotics.
They are isolated with high frequency from all specimen sources. Anaerobic gram-positive cocci such as Peptostreptococcus are the second most recovered anaerobes and account for one quarter of anaerobic isolates found. Most Anaerobic gram-positive cocci are recovered mixed in with other anaerobic or aerobic bacteria from various infections at different sites of the human body; this contributes to the difficulty of isolating Peptostreptococcus organisms. Peptostreptococcus species that are found in clinical infections were once part of the genus known as Peptococcus. Peptostreptococcus is the only genus among anaerobic gram-positive cocci, encountered in clinical infections; as such, Peptostreptococcus species are viewed as being clinically significant anaerobic cocci. Other similar clinically significant anaerobic cocci include Veillonella species, microaerophilic streptococci. Anaerobic gram-positive cocci include various clinically significant species of the genus Peptostreptococcus; some clinically significant Peptostreptococcus species are, Gaffkya anaerobia, renamed Peptostreptococcus tetradius.
The species of anaerobic gram-positive cocci isolated most include Peptostreptococcus magnus, Peptostreptococcus asaccharolyticus, Peptostreptococcus anaerobius, Peptostreptococcus prevotii, Peptostreptococcus micros. Anaerobic gram-positive cocci that produce large amounts of lactic acid during the process of carbohydrate fermentation were reclassified as Streptococcus parvulus and Streptococcus morbillorum from Peptococcus or Peptostreptococcus. Most of these organisms are anaerobic. Due to a large amount of new research done on the human microbe and more information on bacteria, many species of bacteria have been renamed and re-classified. Based on DNA homology and whole-cell polypeptide-pattern study findings supported by phenotypic characteristics, the DNA homology group of microaerobic streptococci, known as Streptococcus anginosus or Streptococcus milleri is now composed of three distinct species: S anginosus, Streptococcus constellatus, Streptococcus intermedius; the microaerobic species S morbillorum was transferred into the genus Gemella.
A new species within the genus Peptostreptococcus is Peptostreptococcus hydrogenalis. Peptostreptococcus infections occur in/on all body sites, including the CNS, neck, abdomen, skin, bone and soft tissues. Adequate therapy must be taken against infections. Peptostreptoccocci are overlooked and they are difficult to isolate, appropriate specimen collection is required. Peptostreptococci grow which makes them resistant to antimicrobrials; the most common Peptostreptococcus species found in infections are P. magnus, P asaccharolyticus, P anaerobius, P prevotii, P micros, Peptostreptococcus saccharolyticus, Peptostreptococcus intermedius. P magnus were recovered in bone and chest infections. P asaccharolyticus and P anaerobius and the highest recovery rate in obstetrical/gynecological and respiratory tract infections and wounds; when anaerobic and facultative cocci were recovered most of the infection were polymicrobial. Most patients from whom microaerophilic streptococci were recovered in pure culture had abscesses, meningitis, or conjunctivitis.
P. Magnus is the most isolated anaerobic cocci and is recovered in pure culture. Other common Peptostreptococci in the different infectious sites are P anaerobius which occurs in oral infections. Many infections caused by peptostreptococcus bacteria are synergistic. Bacterial synergy, the presence of, determined by mutual induction of sepsis enhancement, increased mortality, increased abscess inducement, enhancement of the growth of the bacterial components in mixed infections, is found between anaerobic gram-positive cocci and their aerobic and anaerobic counterparts; the ability
Not to be confused with Haemophilia. Haemophilus is a genus of Gram-negative, coccobacilli bacteria belonging to the family Pasteurellaceae. While Haemophilus bacteria are small coccobacilli, they are categorized as pleomorphic bacteria because of the wide range of shapes they assume; these organisms inhabit the mucous membranes of the upper respiratory tract, mouth and intestinal tract. The genus includes commensal organisms along with some significant pathogenic species such as H. influenzae—a cause of sepsis and bacterial meningitis in young children—and H. ducreyi, the causative agent of chancroid. All members are facultatively anaerobic; this genus has been found to be part of the salivary microbiome. Members of the genus Haemophilus will not grow on blood agar plates, as all species require at least one of these blood factors for growth: hemin and/or nicotinamide adenine dinucleotide, they are unable to synthesize important parts of the cytochrome system needed for respiration, they obtain these substances from the heme fraction, known as the X factor, of blood hemoglobin.
The culture medium must supply the cofactor nicotinamide adenine dinucleotide, known as the V factor. Clinical laboratories use tests for the requirement of the X and V factors to identify the isolates as Haemophilus species.<Chocolate agar is an excellent Haemophilus growth medium, as it allows for increased accessibility to these factors. Alternatively, Haemophilus is sometimes cultured using the "Staph streak" technique: both Staphylococcus and Haemophilus organisms are cultured together on a single blood agar plate. In this case, Haemophilus colonies will grow in small "satellite" colonies around the larger Staphylococcus colonies because the metabolism of Staphylococcus produces the necessary blood factor byproducts required for Haemophilus growth. Haemophilus chapter in Baron's Medical Microbiology. Raw Living Radio Interviews Dr Robert Cassar as part of a 3 Show Series in HD 2014 from the EarthShiftProject.com, an educational and informational research organization
Medical diagnosis is the process of determining which disease or condition explains a person's symptoms and signs. It is most referred to as diagnosis with the medical context being implicit; the information required for diagnosis is collected from a history and physical examination of the person seeking medical care. One or more diagnostic procedures, such as diagnostic tests, are done during the process. Sometimes posthumous diagnosis is considered a kind of medical diagnosis. Diagnosis is challenging, because many signs and symptoms are nonspecific. For example, redness of the skin, by itself, is a sign of many disorders and thus does not tell the healthcare professional what is wrong, thus differential diagnosis, in which several possible explanations are compared and contrasted, must be performed. This involves the correlation of various pieces of information followed by the recognition and differentiation of patterns; the process is made easy by a sign or symptom, pathognomonic. Diagnosis is a major component of the procedure of a doctor's visit.
From the point of view of statistics, the diagnostic procedure involves classification tests. The first recorded examples of medical diagnosis are found in the writings of Imhotep in ancient Egypt. A Babylonian medical textbook, the Diagnostic Handbook written by Esagil-kin-apli, introduced the use of empiricism and rationality in the diagnosis of an illness or disease. Traditional Chinese Medicine, as described in the Yellow Emperor's Inner Canon or Huangdi Neijing, specified four diagnostic methods: inspection, auscultation-olfaction and palpation. Hippocrates was known to make diagnoses by smelling their sweat. A diagnosis, in the sense of diagnostic procedure, can be regarded as an attempt at classification of an individual's condition into separate and distinct categories that allow medical decisions about treatment and prognosis to be made. Subsequently, a diagnostic opinion is described in terms of a disease or other condition, but in the case of a wrong diagnosis, the individual's actual disease or condition is not the same as the individual's diagnosis.
A diagnostic procedure may be performed by various health care professionals such as a physician, physical therapist, healthcare scientist, dentist, nurse practitioner, or physician assistant. This article uses diagnostician as any of these person categories. A diagnostic procedure does not involve elucidation of the etiology of the diseases or conditions of interest, that is, what caused the disease or condition; such elucidation can be useful to optimize treatment, further specify the prognosis or prevent recurrence of the disease or condition in the future. The initial task is to detect a medical indication to perform a diagnostic procedure. Indications include: Detection of any deviation from what is known to be normal, such as can be described in terms of, for example, physiology, pathology and human homeostasis. Knowledge of what is normal and measuring of the patient's current condition against those norms can assist in determining the patient's particular departure from homeostasis and the degree of departure, which in turn can assist in quantifying the indication for further diagnostic processing.
A complaint expressed by a patient. The fact that a patient has sought a diagnostician can itself be an indication to perform a diagnostic procedure. For example, in a doctor's visit, the physician may start performing a diagnostic procedure by watching the gait of the patient from the waiting room to the doctor's office before she or he has started to present any complaints. During an ongoing diagnostic procedure, there can be an indication to perform another, diagnostic procedure for another concomitant, disease or condition; this may occur as a result of an incidental finding of a sign unrelated to the parameter of interest, such as can occur in comprehensive tests such as radiological studies like magnetic resonance imaging or blood test panels that include blood tests that are not relevant for the ongoing diagnosis. General components which are present in a diagnostic procedure in most of the various available methods include: Complementing the given information with further data gathering, which may include questions of the medical history, physical examination and various diagnostic tests.
A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. Diagnostic tests can be used to provide prognostic information on people with established disease. Processing of the answers, findings or other results. Consultations with other providers and specialists in the field may be sought. There are a number of methods or techniques that can be used in a diagnostic procedure, including performing a differential diagnosis or following medical algorithms. In reality, a diagnostic procedure may involve components of multiple methods; the method of differential diagnosis is based on finding as many candidate diseases or conditions as possible that can cause the signs or symptoms, followed by a process of elimination or at least of rendering the entries more or less probable by further medical tests and other processing until, aiming to reach the point where only one candidate disease or condit
Cervical lymphadenopathy refers to lymphadenopathy of the cervical lymph nodes. The term lymphadenopathy speaking refers to disease of the lymph nodes, though it is used to describe the enlargement of the lymph nodes; the term lymphadenitis refers to inflammation of a lymph node, but it is used as a synonym of lymphadenopathy. Cervical lymphadenopathy is a symptom, not a diagnosis; the causes are varied, may be inflammatory, degenerative, or neoplastic. In adults, healthy lymph nodes can be palpable, in the axilla and groin. In children up to the age of 12 cervical nodes up to 1 cm in size may be palpable and this may not signify any disease. If nodes heal by resolution or scarring after being inflamed, they may remain palpable thereafter. In children, most palpable cervical lymphadenopathy is infective. In individuals over the age of 50, metastatic enlargement from cancers of the aerodigestive tract should be considered. Cervical lymphadenopathy can be thought of as local where only the cervical lymph nodes are affected, or general where all the lymph nodes of the body are affected.
Pericoronitis Staphylococcal lymphadenitis Mycobacterial lymphadenitis Rubella Cat scratch fever Infectious mononucleosis Streptococcal pharyngitis Viral respiratory infection Toxoplasmosis Tuberculosis Brucellosis Primary herpes simplex infection Syphilis Cytomegalovirus Human immunodeficiency virus Histoplasmosis Chicken pox Lymph nodes may become enlarged in malignant disease. This cervical lymphadenopathy may be metastatic. Alternatively, enlarged lymph nodes may represent a primary malignancy of the lymphatic system itself, such as lymphoma, lymphocytic leukemia,Metastatic lymph nodes are enlarged because tumor cells have detached from the primary tumor and started growing in the lymph node. Since cancer occurs more in older people, this kind of lymphadenopathy is more common in older persons. Metastatic lymph nodes tend to feel hard and may be fixed to underlying tissues and may or may not be tender; the lymph nodes that directly drain the area of the cancer are affected by the spread.
In such cases, this discovery leads to a search for the primary malignancy, firstly in the nearby area with endoscopy, "blind" biopsies, tonsillectomy on the side of the lymphadenopathy. If no tumor is found the rest of the body is examined, looking for lung cancer or other possible sites. If still no primary tumor is detected, the term "occult primary" is used. In lymphoma there are multiple enlarged nodes which feel rubbery to palpation. Rhabdomyosarcoma Neuroblastoma Surgical trauma, e.g. following a biopsy in the mouth Kawasaki disease, Kikuchi-Fujimoto disease Rosai-Dorfman disease Castleman disease sarcoidosis Lupus erythematosus Cyclic neutropenia Orofacial granulomatosis In possible malignancy, it is routine to perform a throat examination including mirror and/or endoscopy. On ultrasound, B-mode imaging depicts lymph node morphology, whilst power Doppler can assess the vascular pattern. B-mode imaging features that can distinguish metastasis and lymphoma include size, calcification, loss of hilar architecture, as well as intranodal necrosis.
Soft tissue edema and nodal matting on B-mode imaging suggests tuberculous cervical lymphadenitis or previous radiation therapy. Serial monitoring of nodal size and vascularity are useful in assessing treatment response. Fine needle aspiration cytology has a sensitivity and specificity percentages of 81% and 100% in the histopathology of malignant cervical lymphadenopathy. PET-CT has proven to be helpful in identifying occult primary carcinomas of the head and neck when applied as a guiding tool prior to panendoscopy, may induce treatment related clinical decisions in up to 60% of cases
Otorhinolaryngology is a surgical subspecialty within medicine that deals with conditions of the ear and throat and related structures of the head and neck. Doctors who specialize in this area are called otorhinolaryngologists, otolaryngologists, ENT doctors, ENT surgeons, or head and neck surgeons. Patients seek treatment from an otorhinolaryngologist for diseases of the ear, throat, base of the skull, for the surgical management of cancers and benign tumors of the head and neck; the term is a combination of New Latin combining forms derived from four Ancient Greek words: οὖς ous, "ear", ῥίς rhis, "nose", λάρυγξ larynx, "larynx" and -λογία logia, "study". Otorhinolaryngologists are physicians who, in the United States, complete at least five years of surgical residency training; this is composed of six months of general surgical training and four and a half years in specialist surgery. In Canada and the United States, practitioners complete a five-year residency training after medical school.
Following residency training, some otolaryngologist-head & neck surgeons complete an advanced sub-specialty fellowship, where training can be one to two years in duration. In the United States and Canada, otorhinolaryngology is one of the most competitive specialties in medicine in which to obtain a residency position following medical school. In the United Kingdom entrance to otorhinolaryngology higher surgical training is competitive and involves a rigorous national selection process; the training programme consists of 6 years of higher surgical training after which trainees undertake fellowships in a sub-speciality prior to becoming a consultant. In this type of surgery, a surgeon harvests a muscle from the back or from the abdominal region for reconstruction of the skull or the cranial vault. Latissimus is another word for back in the medical field as well as rectus abdominis, your abdominal area; the muscle is sometimes useful for sealing off the central nervous system in ones body and allowing it to heal the complex wounds.
A study was down with five patients who underwent the free muscle transfer for a smile reconstruction. Two of the five patients prior to this surgery had failed their first free muscle transfer; the next two patients had vascular anomalies and one had a previous distal ligation of the facial vessels. In three of the cases, they used a submental vein, in all the cases they used a donor submental artery. “In all 5 the gracilis vascular pedicle comprised a muscular branch of the profunda femoris together with its venae comitantes, with the artery and vein ranging in size from 1.0 to 1.5 mm and 2.0 to 2.5 mm, respectively. The submental artery provided an excellent size match in all cases, ranging in size from 1.0 to 1.5 mm”. The first patient was a 45 year old woman who developed a dense flaccid right facial paralysis at the age of 33; the second patient was an 8 year old girl who had developed dense flaccid left facial paralysis after a laser treatment at four weeks for, “bilateral infantile segmental hemangiomas in the distribution of the mandibular division of the trigeminal nerve.
“. The third case was a 19 year old male who had developed a segmental right facial paralysis after a excision of a infantile parotid hemangioma at the age of 2; the fourth case was a 20 year old woman who had developed dense flaccid right facial paralysis after a biopsy of a pontomedullary junction tumor at the age of 2. Lastly, case five was a 19 year old woman. Bone defects are the most difficult reconstructions as it requires precise alignment. Bone transfer is used for the mandibular reconstruction, but it now allows surgeons to use it for the midface and the orbito maxillary. If for some reason the fibula is not available for transfer, another option the team may go is using the back rib free flap; this allows the transfer to give the bone volume for the patients. The earliest first bone transfer was done all the way back in 2000 BCE when the Peruvian priest implanted a metallic plate to reconstruct the contour defects of the religious trephination. In 1668, a man by the name of Jobs van Meekeren reported the use of dog bone grafts to reconstruct the calvarium in the soldier.
“…the ideal of the future: the insertion of a piece of living bone which will fill the gap and will continue to live without absorption.”. The radial forearm is the most dominant use of flap to be used to coverage up damages. Today, the anterolateral thigh flap is being used on patients for the head and the neck because it has an ideal match for the site and it is easy to harvest. If a surgeon chose to remove/harvest the tissue, safe places are the following. Microvascular reconstruction repair is a common operation, done on patients who see a Otorhinolaryngologist. Microvascular reconstruction repair is a surgical procedure that involves moving a composite piece of tissue from the patient's body and moves it to the head and or neck. Microvascular head and neck reconstruction is used to treat head and neck cancers, including those of the larynx and pharynx, oral cavity, salivary glands, calvarium, sinuses and skin; the tissue, most common moved during this procedure is from the arms, legs and can come from the skin, fat, or muscle.
When doing this procedure, the decision on, moved is determined on the reconstructive needs. T
Metronidazole, marketed under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease and bacterial vaginosis, it is effective for dracunculiasis, giardiasis and amebiasis. It is an option for a first episode of mild-to-moderate Clostridium difficile colitis if vancomycin or fidaxomicin is unavailable. Metronidazole is available by mouth, as a cream, by injection into a vein. Common side effects include nausea, a metallic taste, loss of appetite, headaches. Seizures or allergies to the medication may occur; some state that metronidazole should not be used in early pregnancy, while others state doses for trichomoniasis are safe. It should not be used. Metronidazole began to be commercially used in 1960 in France, it is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. It is available in most areas of the world.
The pills are inexpensive, costing between 0.01 and 0.10 USD each. In the United States, it is about 26 USD for ten days of treatment. In 2016, it was the 71st most prescribed medication in the United States, with more than 11 million prescriptions. Metronidazole is used to treat: bacterial vaginosis, pelvic inflammatory disease, pseudomembranous colitis, aspiration pneumonia, fungating wounds, intra-abdominal infections, lung abscess, amoebiasis, oral infections, giardiasis and infections caused by susceptible anaerobic organisms such as Bacteroides, Clostridium, Peptostreptococcus, Prevotella species, it is often used to eradicate Helicobacter pylori along with other drugs and to prevent infection in people recovering from surgery. Metronidazole is bitter and so the liquid suspension contains metronidazole benzoate; this requires hydrolysis in the stomach and so may be unsuitable in people with diarrhea or feeding-tubes in the duodenum or jejunum. Drugs of choice for the treatment of bacterial vaginosis include clindamycin.
The treatment of choice for bacterial vaginosis in nonpregnant women include metronidazole oral twice daily for seven days, or metronidazole gel intravaginally once daily for five days, or clindamycin intravaginally at bedtime for seven days. For pregnant women, the treatment of choice is metronidazole oral three times a day for seven days. Data does not report routine treatment of male sexual partners; the 5-nitroimidazole drugs are the mainstay of treatment for infection with Trichomonas vaginalis. Treatment for both the infected patient and the patient's sexual partner is recommended if asymptomatic. Therapy other than 5-nitroimidazole drugs is an option, but cure rates are much lower. Oral metronidazole is a treatment option for giardiasis, the increasing incidence of nitroimidazole resistance is leading to the increased use of other compound classes. In the case of Dracunculus, metronidazole just eases worm extraction rather than killing the worm. Initial antibiotic therapy for less-severe Clostridium difficile colitis consists of metronidazole, vancomycin, or fidaxomicin by mouth.
In 2017 the IDSA recommended vancomycin and fidaxomicin over metronidazole. Vancomycin by mouth has been shown to be more effective in treating people with severe C. difficile colitis. Entamoeba histolytica invasive amebiasis is treated with metronidazole for eradication, in combination with diloxanide to prevent recurrence. Metronidazole has been used in women to prevent preterm birth associated with bacterial vaginosis, amongst other risk factors including the presence of cervicovaginal fetal fibronectin. Metronidazole was ineffective in preventing preterm delivery in high-risk pregnant women and, the incidence of preterm delivery was found to be higher in women treated with metronidazole. Common adverse drug reactions associated with systemic metronidazole therapy include: nausea, weight loss, abdominal pain, headache and metallic taste in the mouth. Intravenous administration is associated with thrombophlebitis. Infrequent adverse effects include: hypersensitivity reactions, dizziness, glossitis, dark urine, paraesthesia.
High doses and long-term systemic treatment with metronidazole are associated with the development of leucopenia, increased risk of peripheral neuropathy, central nervous system toxicity. Common adverse drug reaction associated with topical metronidazole therapy include local redness and skin irritation. Metronidazole has been associated with cancer in animal studies; some evidence from studies in rats indicates the possibility it may contribute to serotonin syndrome, although no case reports documenting this have been published to date. Metronidazole is listed by the US National Toxicology Program as reasonably anticipated to be a human carcinogen. Although some of the testing methods have been questioned, oral exposure has been shown to cause cancer in experimental animals and has demonstrated some mutagenic effects in bacterial cultures; the relationship between exposure to metronidazole and human cancer is unclear. One study found an excess in lung cancer among women, while other studies found either no increased risk, or a statistically insignificant risk.
Metronidazole is listed as a possible carcin