The diagnosis of actinomycosis can be a difficult one to make. In addition to microbiological examinations, magnetic resonance imaging and immunoassays may be helpful.

"Actinomyces" bacteria are generally sensitive to penicillin, which is frequently used to treat actinomycosis. In cases of penicillin allergy, doxycycline is used.

Sulfonamides such as sulfamethoxazole may be used as an alternative regimen at a total daily dosage of 2-4 grams. Response to therapy is slow and may take months.

Hyperbaric oxygen therapy may also be used as an adjunct to conventional therapy when the disease process is refractory to antibiotics and surgical treatment.

The affected areas are treated with iodine solutions. A common method to achieve this is to give the cattle sodium iodide orally on a regular treatment schedule. Antibiotics such as Tetracyclines are also used. These two treatment methods can be used alone or together; simultaneous use is considered more aggressive. Killing the bacteria that cause the infection is the ultimately purpose of these treatment methods. However, they are seldom effective unless treatment is started very early.

It is notable that surgery is not typically considered for treatment of cattle as it is in extreme human cases.

Recovery from an anaerobic infection depends on adequate and rapid management. The main principles of managing anaerobic infections are neutralizing the toxins produced by anaerobic bacteria, preventing the local proliferation of these organisms by altering the environment and preventing their dissemination and spread to healthy tissues.

Toxin can be neutralized by specific antitoxins, mainly in infections caused by Clostridia (tetanus and botulism). Controlling the environment can be attained by draining the pus, surgical debriding of necrotic tissue, improving blood circulation, alleviating any obstruction and by improving tissue oxygenation. Therapy with hyperbaric oxygen (HBO) may also be useful. The main goal of antimicrobials is in restricting the local and systemic spread of the microorganisms.

The available parenteral antimicrobials for most infections are metronidazole, clindamycin, chloramphenicol, cefoxitin, a penicillin (i.e. ticarcillin, ampicillin, piperacillin) and a beta-lactamase inhibitor (i.e. clavulanic acid, sulbactam, tazobactam), and a carbapenem (imipenem, meropenem, doripenem, ertapenem). An antimicrobial effective against Gram-negative enteric bacilli (i.e. aminoglycoside) or an anti-pseudomonal cephalosporin (i.e. cefepime ) are generally added to metronidazole, and occasionally cefoxitin when treating intra-abdominal infections to provide coverage for these organisms. Clindamycin should not be used as a single agent as empiric therapy for abdominal infections. Penicillin can be added to metronidazole in treating of intracranial, pulmonary and dental infections to provide coverage against microaerophilic streptococci, and Actinomyces.

Oral agents adequate for polymicrobial oral infections include the combinations of amoxicillin plus clavulanate, clindamycin and metronidazole plus a macrolide. Penicillin can be added to metronidazole in the treating dental and intracranial infections to cover "Actinomyces" spp., microaerophilic streptococci, and "Arachnia" spp. A macrolide can be added to metronidazole in treating upper respiratory infections to cover "S. aureus" and aerobic streptococci. Penicillin can be added to clindamycin to supplement its coverage against "Peptostreptococcus" spp. and other Gram-positive anaerobic organisms.

Doxycycline is added to most regimens in the treatment of pelvic infections to cover chlamydia and mycoplasma. Penicillin is effective for bacteremia caused by non-beta lactamase producing bacteria. However, other agents should be used for the therapy of bacteremia caused by beta-lactamase producing bacteria.

Because the length of therapy for anaerobic infections is generally longer than for infections due to aerobic and facultative anaerobic bacteria, oral therapy is often substituted for parenteral treatment. The agents available for oral therapy are limited and include amoxacillin plus clavulanate, clindamycin, chloramphenicol and metronidazole.

In 2010 the American Surgical Society and American Society of Infectious Diseases have updated their guidelines for the treatment of abdominal infections.

The recommendations suggest the following:

For mild-to-moderate community-acquired infections in adults, the agents recommended for empiric regimens are: ticarcillin- clavulanate, cefoxitin, ertapenem, moxifloxacin, or tigecycline as single-agent therapy or combinations of metronidazole with cefazolin, cefuroxime, ceftriaxone, cefotaxime, levofloxacin, or ciprofloxacin. Agents no longer recommended are: cefotetan and clindamycin ( Bacteroides fragilis group resistance) and ampicillin-sulbactam (E. coli resistance) and ainoglycosides (toxicity).

For high risk community-acquired infections in adults, the agents recommended for empiric regimens are: meropenem, imipenem-cilastatin, doripenem, piperacillin-tazobactam, ciprofloxacin or levofloxacin in combination with metronidazole, or ceftazidime or cefepime in combination with metronidazole. Quinolones should not be used unless hospital surveys indicate >90% susceptibility of "E. coli" to quinolones.

Aztreonam plus metronidazole is an alternative, but addition of an agent effective against gram-positive cocci is recommended. The routine use of an aminoglycoside or another second agent effective against gram-negative facultative and aerobic bacilli is not recommended in the absence of evidence that the infection is caused by resistant organisms that require such therapy.

Empiric use of agents effective against enterococci is recommended and agents effective against methicillin-resistant "S. aureus" (MRSA) or yeast is not recommended in the absence of evidence of infection due to such organisms.

Empiric antibiotic therapy for health care-associated intra-abdominal should be driven by local microbiologic results. Empiric coverage of likely pathogens may require multidrug regimens that include agents with expanded spectra of activity against gram-negative aerobic and facultative bacilli. These include meropenem, imipenem-cilastatin, doripenem, piperacillin-tazobactam, or ceftazidime or cefepime in combination with metronidazole. Aminoglycosides or colistin may be required.

Antimicrobial regimens for children include an aminoglycoside-based regimen, a carbapenem (imipenem, meropenem, or ertapenem), a beta-lactam/beta-lactamase-inhibitor combination (piperacillin-tazobactam or ticarcillin-clavulanate), or an advanced-generation cephalosporin (cefotaxime, ceftriaxone, ceftazidime, or cefepime) with metronidazole.

Clinical judgment, personal experience, safety and patient compliance should direct the physician in the choice of the appropriate antimicrobial agents. The length of therapy generally ranges between 2 and 4 weeks, but should be individualized depending on the response. In some instances treatment may be required for as long as 6–8 weeks, but can often be shortened with proper surgical drainage.

Diagnosis can be achieved through blood cultures, or cultures of other bodily fluids such as sputum. Bone marrow culture can often yield an earlier diagnosis, but is usually avoided as an initial diagnostic step because of its invasiveness.

Many people will have anemia and neutropenia if bone marrow is involved. MAC bacteria should always be considered in a person with HIV infection presenting with diarrhea.

The diagnosis requires consistent symptoms with two additional signs:

- Chest X-ray or CT scan showing evidence of right middle lobe (or left lingular lobe) lung infection

- Sputum culture or bronchoalveolar lavage culture demonstrating the infection is caused by MAC

Disseminated MAC is most readily diagnosed by one positive blood culture. Blood cultures should be performed in patients with symptoms, signs, or laboratory abnormalities compatible with mycobacterium infection. Blood cultures are not routinely recommended for asymptomatic persons, even for those who have CD4+ T-lymphocyte counts less than 100 cells/uL.

Diagnosis of nocardiosis can be done by a doctor using various techniques. These techniques include, but are not limited to: a chest x-rays of the lung, a bronchoscopy, a brain/lung/skin biopsy, or a sputum culture.

However, diagnosis may be difficult. Nocardiae are gram positive weakly acid-fast branching rod-shaped bacteria and can be visualized by a modified Ziehl–Neelsen stain like Fite-Faraco method. In the clinical laboratory, routine cultures may be held for insufficient time to grow nocardiae, and referral to a reference laboratory may be needed for species identification. Infiltration and pleural effusion are usually seen via x-ray.

The prognosis of nocardiosis is highly variable. The state of the host's health, site, duration, and severity of the infection all play parts in determining the prognosis. As of now, skin and soft tissue infections have a 100% cure rate, and pleuropulmonary infections have a 90% cure rate with appropriate therapy. The cure rate falls to 63% with those infected with dissemented nocardiosis, with only half of those surviving infections that cause brain abscess. Additionally, 44% of people who are infected in the spinal cord/brain die, increasing to 85% if that person has an already weakened immune system. Unfortunately, there is not a preventative to nocardiosis. The only recommendation is to protect open wounds to limit access.

A skin and skin structure infection (SSSI), also referred to as skin and soft tissue infection (SSTI) or acute bacterial skin and skin structure infection (ABSSSI), is an infection of skin and associated soft tissues (such as loose connective tissue and mucous membranes). The pathogen involved is usually a bacterial species. Such infections often requires treatment by antibiotics.

Until 2008, two types were recognized, complicated skin and skin structure infection (cSSSI) and uncomplicated skin and skin structure infection (uSSSI). "Uncomplicated" SSSIs included simple abscesses, impetiginous lesions, furuncles, and cellulitis. "Complicated" SSSIs included infections either involving deeper soft tissue or requiring significant surgical intervention, such as infected ulcers, burns, and major abscesses or a significant underlying disease state that complicates the response to treatment. Superficial infections or abscesses in an anatomical site, such as the rectal area, where the risk of anaerobic or gram-negative pathogen involvement is higher, should be considered complicated infections. The two categories had different regulatory approval requirements. The uncomplicated category (uSSSI) is normally only caused by "Staphylococcus aureus" and "Streptococcus pyogenes", whereas the complicated category (cSSSI) might also be caused by a number of other pathogens. In cSSSI, the pathogen is known in only about 40% of cases.

Because cSSSIs are usually serious infections, physicians do not have the time for a culture to identify the pathogen, so most cases are treated empirically, by choosing an antibiotic agent based on symptoms and seeing if it works. For less severe infections, microbiologic evaluation via tissue culture has been demonstrated to have high utility in guiding management decisions. To achieve efficacy, physicians use broad-spectrum antibiotics. This practice contributes in part to the growing incidence of antibiotic resistance, a trend exacerbated by the widespread use of antibiotics in medicine in general. The increased prevalence of antibiotic resistance is most evident in methicillin-resistant "Staphylococcus aureus" (MRSA). This species is commonly involved in cSSSIs, worsening their prognosis, and limiting the treatments available to physicians. Drug development in infectious disease seeks to produce new agents that can treat MRSA.

Since 2008, the U.S. Food and Drug Administration has changed the terminology to "acute bacterial skin and skin structure infections" (ABSSSI). The Infectious Diseases Society of America (IDSA) has retained the term "skin and soft tissue infection".

As is often the case, there are diseases/conditions with signs and symptoms that are similar to actinomycosis. As such, misdiagnoses can occur. Some examples include abscesses caused by grass seeds, woody tongue, bottle jaw, cancerous growths, and irritation caused by lodged objects.

In a normal umbilical stump, you first see the umbilicus lose its characteristic bluish-white, moist appearance and become dry and black After several days to weeks, the stump should fall off and leave a pink fleshy wound which continues to heal as it becomes a normal umbilicus.

For an infected umbilical stump, diagnosis is usually made by the clinical appearance of the umbilical cord stump and the findings on history and physical examination. There may be some confusion, however, if a well-appearing neonate simply has some redness around the umbilical stump. In fact, a mild degree is common, as is some bleeding at the stump site with detachment of the umbilical cord. The picture may be clouded even further if caustic agents have been used to clean the stump or if silver nitrate has been used to cauterize granulomata of the umbilical stump.

In addition to hand washing, gloves play an important role in reducing the risks of transmission of microorganisms. Gloves are worn for three important reasons in hospitals. First, they are worn to provide a protective barrier for personnel, preventing large scale contamination of the hands when touching blood, body fluids, secretions, excretions, mucous membranes, and non-intact skin. In the United States, the Occupational Safety and Health Administration has mandated wearing gloves to reduce the risk of bloodborne pathogen infections. Second, gloves are worn to reduce the likelihood that microorganisms present on the hands of personnel will be transmitted to patients during invasive or other patient-care procedures that involve touching a patient's mucous membranes and nonintact skin. Third, they are worn to reduce the likelihood that the hands of personnel contaminated with micro-organisms from a patient or a fomite can transmit those micro-organisms to another patient. In this situation, gloves must be changed between patient contacts, and hands should be washed after gloves are removed.

Wearing gloves does not replace the need for handwashing, because gloves may have small, undtectable defects or may be torn during use, and hands can become contaminated during removal of gloves. Failure to change gloves between patient contacts is an infection control hazard.

Female genital tract infections caused by anaerobic bacteria are polymicrobial and include: soft-tissue perineal, vulvar and Bartholin gland abscesses; bacterial vaginosis; endometritis; pyometra; salpingitis; adnexal abscess; tubo-ovarian abscesses; intrauterine contraceptive device-associated infection; pelvic inflammatory disease, which may include pelvic cellulitis and abscess; amnionitis; septic pelvic thrombophlebitis; septic abortion; and postsurgical obstetric and gynecologic infections., Getting adequate microbiological cultures is essential. It is important to avoid contaminating the culture with the normal genital flora. Methods that can ensure adequate cultures are laparoscopy, culdocentesis, or obtaining quantitative endometrial cultures employing a telescoping catheter.

The anaerobes often recovered include "Prevotella bivia, Prevotella disiens", and "Peptostreptococcus, Porphyromonas" and "Clostridium" spp. "Bacteroides fragilis" group is rarely recovered in these infections compared to intra-abdominal infection." Actinomyces" spp. and "Eubacterium nodatum" are often recovered in infections associated with intrauterine devices. Mobiluncus spp. can be associated with bacterial "vaginosis". The aerobic bacteria also found mixed with these anaerobic bacteria include Enterobacteriaceae, "Streptococcus" spp. (including groups A and B), "Neisseria gonorrhoeae", "Chlamydia" spp. and "Mycoplasma hominis". Free gas in the tissues, abscess formation and foul-smelling discharge is commonly associated with the presence of anaerobic bacteria. Treatment of these infections includes the use of antimicrobials active against all of the potential aerobic and anaerobic bacterial pathogens. Antimicrobials against sexually transmissible pathogens should also be administered.

Opportunistic infections caused by Feline Leukemia Virus and Feline immunodeficiency virus retroviral infections can be treated with Lymphocyte T-Cell Immune Modulator.

The methods used differ from country to country (definitions used, type of nosocomial infections covered, health units surveyed, inclusion or exclusion of imported infections, etc.), so the international comparisons of nosocomial infection rates should be made with the utmost care.

MAC in patients with HIV disease is theorized to represent recent acquisition rather than latent infection reactivating (which is the case in many other opportunistic infections in immunocompromised patients).

The risk of MAC is inversely related to the patient's CD4 count, and increases significantly when the CD4 count decreases below 50 cells/mm³. Other risk factors for acquisition of MAC infection include using an indoor swimming pool, consumption of raw or partially cooked fish or shellfish, bronchoscopy and treatment with granulocyte stimulating factor.

Disseminated disease was previously the common presentation prior to the advent of highly active antiretroviral therapy (HAART). Today, in regions where HAART is the standard of care, localized disease presentation is more likely. This generally includes a focal lymphadenopathy/lymphadenitis.

Bumblefoot is so named because of the characteristic "bumbles" or lesions, as well as swelling of the foot pad, symptomatic of an infection. Topical antiseptics in addition to oral or injected antibiotics may be used to combat the infection, which if left untreated may be fatal.

During the 1950s there were outbreaks of omphalitis that then led to anti-bacterial treatment of the umbilical cord stump as the new standard of care. It was later determined that in developed countries keeping the cord dry is sufficient, (known as "dry cord care") as recommended by the American Academy of Pediatrics. The umbilical cord dries more quickly and separates more readily when exposed to air However, each hospital/birthing center has its own recommendations for care of the umbilical cord after delivery. Some recommend not using any medicinal washes on the cord. Other popular recommendations include triple dye, betadine, bacitracin, or silver sulfadiazine. With regards to the medicinal treatments, there is little data to support any one treatment (or lack thereof) over another. However one recent review of many studies supported the use of chlorhexidine treatment as a way to reduce risk of death by 23% and risk of omphalitis by anywhere between 27-56% in community settings in underdeveloped countries. This study also found that this treatment increased the time that it would take for the umbilical stump to separate or fall off by 1.7 days. Lastly this large review also supported the notion that in hospital settings no medicinal type of cord care treatment was better at reducing infections compared to dry cord care.

Individuals at higher risk are often prescribed prophylactic medication to prevent an infection from occurring. A patient's risk level for developing an opportunistic infection is approximated using the patient's CD4 T-cell count and sometimes other markers of susceptibility. Common prophylaxis treatments include the following:

Among individuals being treated in intensive care units, the mortality rate is about 30-50% when systemic candidiasis develops.

Treatment of AIT involves antibiotic treatment. Based on the offending organism found on microscopic examination of the stained fine needle aspirate, the appropriate antibiotic treatment is determined. In the case of a severe infection, systemic antibiotics are necessary. Empirical broad spectrum antimicrobial treatment provides preliminary coverage for a variety of bacteria, including "S. aureus" and "S. pyogenes." Antimicrobial options include penicillinase-resistant penicillins (ex: cloxacillin, dicloxacillin) or a combination of a penicillin and a beta-lactamase inhibitor. However, in patients with a penicillin allergy, clindamycin or a macrolide can be prescribed. The majority of anaerobic organisms involved with AIT are susceptible to penicillin. Certain Gram-negative bacilli (ex: "Prevotella", "Fusobacteria", and "Porphyromonas") are exhibiting an increased resistance based on the production of beta-lactamase. Patients who have undergone recent penicillin therapy have demonstrated an increase in beta-lactamase-producing (anaerobic and aerobic) bacteria. Clindamycin, or a combination of metronidazole and a macrolide, or a penicillin combined with a beta-lactamase inhibitor is recommended in these cases. Fungal thyroiditis can be treated with amphotericin B and fluconazole. Early treatment of AIT prevents further complications. However, if antibiotic treatment does not manage the infection, surgical drainage is required. Symptoms or indications requiring drainage include continued fever, high white blood cell count, and continuing signs of localized inflammation. The draining procedure is also based on clinical examination or ultrasound/CT scan results that indicate an abscess or gas formation. Another treatment of AIT involves surgically removing the fistula. This treatment is often the option recommended for children. However, in cases of an antibiotic resistant infection or necrotic tissue, a lobectomy is recommended. If diagnosis and/or treatment is delayed, the disease could prove fatal.

The abscesses within the muscle must be drained surgically (not all patient require surgery if there is no abscess). Antibiotics are given for a minimum of three weeks to clear the infection.

The decision to treat bacteriuria depends on the presence of accompany symptoms and comorbidities.

In 2016, thermography was used to identify and evaluate bumblefoot lesions in 67 captive penguins from three species.

Symptoms of vaginal candidiasis are also present in the more common bacterial vaginosis; aerobic vaginitis is distinct and should be excluded in the differential diagnosis. In a 2002 study, only 33% of women who were self-treating for a yeast infection actually had such an infection, while most had either bacterial vaginosis or a mixed-type infection.

Diagnosis of a yeast infection is done either via microscopic examination or culturing. For identification by light microscopy, a scraping or swab of the affected area is placed on a microscope slide. A single drop of 10% potassium hydroxide (KOH) solution is then added to the specimen. The KOH dissolves the skin cells, but leaves the "Candida" cells intact, permitting visualization of pseudohyphae and budding yeast cells typical of many "Candida" species.

For the culturing method, a sterile swab is rubbed on the infected skin surface. The swab is then streaked on a culture medium. The culture is incubated at 37 °C (98.6 °F) for several days, to allow development of yeast or bacterial colonies. The characteristics (such as morphology and colour) of the colonies may allow initial diagnosis of the organism causing disease symptoms.

Respiratory, gastrointestinal, and esophageal candidiasis require an endoscopy to diagnose. For gastrointestinal candidiasis, it is necessary to obtain a 3–5 milliliter sample of fluid from the duodenum for fungal culture. The diagnosis of gastrointestinal candidiasis is based upon the culture containing in excess of 1,000 colony-forming units per milliliter.

Risk factors have been identified which indicate what women will be more likely to develop TOA. These are: increased age, IUD insertion, chlamydia infection, and increased levels of certain proteins (CRP and CA-125) and will alert clinicians to follow up on unresolved symptoms of PID.