Two sets of blood cultures (aerobic and anaerobic) should be taken without delaying the initiation of antibitoics. Cultures from other sites such as respiratory secretions, urine, wounds, cerebrospinal fluid, and catheter insertion sites (in-situ more than 48 hours) can be taken if infections from these sites are suspected. In severe sepsis and septic shock, broad-spectrum antibiotics (usually two, a β-lactam antibiotic with broad coverage, or broad-spectrum carbapenem combined with fluoroquinolones, macrolides, or aminoglycosides) are recommended. However, combination of antibiotics is not recommended for the treatment of sepsis but without shock and immuno-compromised persons unless the combination is used to broaden the anti-bacterial activity. The choice of antibiotics is important in determining the survival of the person. Some recommend they be given within one hour of making the diagnosis, stating that for every hour of delay in the administration of antibiotics, there is an associated 6% rise in mortality. Others did not find a benefit with early administration.

Several factors determine the most appropriate choice for the initial antibiotic regimen. These factors include local patterns of bacterial sensitivity to antibiotics, whether the infection is thought to be a hospital or community-acquired infection, and which organ systems are thought to be infected. Antibiotic regimens should be reassessed daily and narrowed if appropriate. Treatment duration is typically 7–10 days with the type of antibiotic used directed by the results of cultures. In case the culture result is negative, antibiotics should be de-escalated according to person's clinical response or stopped altogether if infection is not present to decrease the chances that the person is infected with multiple drug resistance organisms. In case of people having high risk of being infected with multiple drug resistance organisms such as "Pseudomonas aeruginosa", "Acinetobacter baumannii", addition of antibiotic specific to gram-negative organism is recommended. For Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin and teicoplanin is recommanded. For Legionella infection, addition of macrolide or fluoroquinolone is chosen. If fungal infection is suspected, echinocandin (caspofungin and micafungin) is chosen for people with severe sepsis, followed by triazole (fluconazole and itraconazole) for less ill people. Prolonged antibiotic prophylaxis is not recommended in people who has SIRS without any infectious origion such as acute pancreatitis and burns unless sepsis is suspected.

Once daily dosing of aminoglycoside is sufficient to achieve peak plasma concentration for clinical response without kidney toxicity. Meanwhile, for antibiotics with low volume distribution (vancomycin, teicoplanin, colistin), loading dose is required to achieve adequate therapeutic level to fight infections. Frequent infusions of beta-lactam antibiotics without exceeding total daily dose would help to keep the antibiotics level above minimum inhibitory concentration (MIC), thus providing better clinical response. Giving beta-lactam antibiotics continuously may be better than giving them intermittently. Access to therapeutic drug monitoring is important to ensure adequate drug therapeutic level while at the same time preventing the drug from reaching toxic level.

General anaesthesia is recommended for people with sepsis who require surgical procedures to remove the infective source. Inhalational and intravenous anaesthetics are used. Requirements for anaesthetics may be reduced. Inhalational anaesthetics can reduce the level of proinflammatory cytokines, altering leukocyte adhesion and proliferation, inducing apoptosis (cell death) of the lymphocytes, possibly with a toxic effect on mitochondrial function. Although etomidate has a minimal effect on the cardiovascular system, it is often not recommended as a medication to help with intubation in this situation due to concerns it may lead to poor adrenal function and an increased risk of death. The small amount of evidence there is, however, has not found a change in the risk of death with etomidate.

It is recommended that the head of the bed be raised if possible to improve ventilation. Paralytic agents should be avoided unless ARDS is suspected.

Antibiotics are usually prescribed, with the agent selected based on suspected organism and presence or absence of purulence, although the best treatment choice is unclear. If an abscess is also present, surgical drainage is usually indicated, with antibiotics often prescribed for co-existent cellulitis, especially if extensive. Pain relief is also often prescribed, but excessive pain should always be investigated, as it is a symptom of necrotizing fasciitis. Elevation of the affected area is often recommended.

Steroids may speed recovery in those on antibiotics.

Antibiotics choices depend on regional availability, but a penicillinase-resistant semisynthetic penicillin or a first-generation cephalosporin is currently recommended for cellulitis without abscess. A course of antibiotics is not effective in between 6 and 37% of cases.

Immediate treatment is very important for someone with orbital cellulitis. Treatment typically involves intravenous (IV) antibiotics in the hospital and frequent observation (every 4–6 hours). Along with this several laboratory tests are run including a complete blood count, differential, and blood culture.

- Antibiotic therapy – Since orbital cellulitis is commonly caused by "Staphylococcus" and "Streptococcus" species both penicillins and cephalosporins are typically the best choices for IV antibiotics. However, due to the increasing rise of MRSA (methicillin-resistant "Staphylococcus aureus") orbital cellulitis can also be treated with Vancomycin, Clindamycin, or Doxycycline. If improvement is noted after 48 hours of IV antibiotics, healthcare professions can then consider switching a patient to oral antibiotics (which must be used for 2–3 weeks).

- Surgical intervention – An abscess can threaten the vision or neurological status of a patient with orbital cellulitis, therefore sometimes surgical intervention is necessary. Surgery typically requires drainage of the sinuses and if a subperiosteal abscess is present in the medial orbit, drainage can be performed endoscopically. Post-operatively, patients must follow up regularly with their surgeon and remain under close observation.

Although orbital cellulitis is considered an ophthalmic emergency the prognosis is good if prompt medical treatment is received.

High-dose antibiotics are administered by the intravenous route to maximize diffusion of antibiotic molecules into vegetation(s) from the blood filling the chambers of the heart. This is necessary because neither the heart valves nor the vegetations adherent to them are supplied by blood vessels. Antibiotics are typically continued for two to six weeks depending on the characteristics of the infection and the causative microorganisms.

In acute endocarditis, due to the fulminant inflammation empirical antibiotic therapy is started immediately after the blood has been drawn for culture. This usually includes vancomycin and ceftriaxone IV infusions until the microbial identification and susceptibility report with the minimum inhibitory concentration becomes available allowing for modification of the antimicrobial therapy to target the specific microorganism. It should be noted that the routine use of gentamicin to treat endocarditis has fallen out of favor due to the lack of evidence to support its use (except in infections caused by "Enterococcus" and nutritionally variant "streptococci") and the high rate of complications.

In subacute endocarditis, where patient's hemodynamic status is usually stable, antibiotic treatment can be delayed till the causative microorganism can be identified.

The most common organism responsible for infective endocarditis is "Staphylococcus aureus", which is resistant to penicillin in most cases. High rates of resistance to oxacillin are also seen, in which cases treatment with vancomycin is required.

Viridans group "streptococci" and "Streptococcus bovis" are usually highly susceptible to penicillin and can be treated with penicillin or ceftriaxone.

Relatively resistant strains of viridans group "streptococci" and "Streptococcus bovis" are treated with penicillin or ceftriaxone along with a shorter 2 week course of an aminoglycoside during the initial phase of treatment.

Highly penicillin resistant strains of viridans group "streptococci", nutritionally variant "streptococci" like "Granulicatella sp.", "Gemella sp." and "Abiotrophia defectiva", and "Enterococci" are usually treated with a combination therapy consisting of penicillin and an aminoglycoside for the entire duration of 4–6 weeks.

Selected patients may be treated with a relatively shorter course of treatment (2 weeks) with benzyl penicillin IV if infection is caused by viridans group "streptococci" or "Streptococcus bovis" as long as the following conditions are met:

- Endocarditis of a native valve, not of a prosthetic valve

- An MIC ≤ 0.12 mg/l

- Complication such as heart failure, arrhythmia, and pulmonary embolism occur

- No evidence of extracardiac complication like septic thromboembolism

- No vegetations > 5mm in diameter conduction defects

- Rapid clinical response and clearance of blood stream infection

Additionally oxacillin susceptible "Staphylococcus aureus" native valve endocarditis of the right side can also be treated with a short 2 week course of a beta-lactam antibiotic like nafcillin with or without aminoglycosides.

Surgical debridement of infected material and replacement of the valve with a mechanical or bioprosthetic artificial heart valve is necessary in certain situations:

- Patients with significant valve stenosis or regurgitation causing heart failure

- Evidence of hemodynamic compromise in the form of elevated end-diastolic left ventricular or left atrial pressure or moderate to severe pulmonary hypertension

- Presence of intracardiac complications like paravalvular abscess, conduction defects or destructive penetrating lesions

- Recurrent septic emboli despite appropriate antibiotic treatment

- Large vegetations (> 10 mm)

- Persistently positive blood cultures despite appropriate antibiotic treatment

- Prosthetic valve dehiscence

- Relapsing infection in the presence of a prosthetic valve

- Abscess formation

- Early closure of mitral valve

- Infection caused by fungi or resistant Gram negative bacteria.

The guidelines were recently updated by both the American College of Cardiology and the European Society of Cardiology. There was a recent meta-analysis published that showed surgical intervention at 7 days or less is associated with lower mortality .

Infective endocarditis is associated with 18% in-hospital mortality.

Antibiotics have been used to prevent and treat these infections however the misuse of antibiotics is a serious problem for global health. It is recommended that guidelines be followed which outline when it is appropriate to give antibiotics and which antibiotics are most effective.

Atelectasis: mild to moderate fever, no changes or mild rales on chest auscultation.

Management: pulmonary exercises, ambulation (deep breathing and walking)

Urinary tract infection : high fever, malaise, costovertebral tenderness, positive urine culture.

Management: antibiotics as per culture sensitivity (cephalosporine).

Endometritis: moderate fever, exquisite uterine tenderness, minimal abdominal findings.

Management: multiple agent IV antibiotics to cover polymicrobial organisms: clindamycin, gentamicin, addition of ampicillin if no response, no cultures are necessary.

Wound infection: persistent spiking fever despite antibiotics, wound erythema or fluctuance, wound drainage.

Management: antibiotics for cellulitis, open and drain wound, saline-soaked packing twice a day, secondary closure.

Septic pelvic thrombophlebitis: persistent wide fever swings despite antibiotics, usually normal abdominal or pelvic exams.

Management: IV heparin for 7–10 days at rates sufficient to prolong the PTT to double the baseline values.

Mastitis: unilateral, localized erythema, edema, tenderness.

Management: antibiotics for cellulitis, open and drain abscess if present.

"S. pneumonia" can be treated with a combination of penicillin and ampicillin.

In cases of herpes simplex virus-derived meningitis, antiviral therapy (acyclovir or vidarabine) must be started immediately for a favorable outcome. Acyclovir is a better antiviral because it shows a similar effect on the infection as vidarabine and is safer to use in the neonate. The recommended dosage is 20 mg/kg every six hours for 21 days.

When infection attacks the body, "anti-infective" drugs can suppress the infection. Several broad types of anti-infective drugs exist, depending on the type of organism targeted; they include antibacterial (antibiotic; including antitubercular), antiviral, antifungal and antiparasitic (including antiprotozoal and antihelminthic) agents. Depending on the severity and the type of infection, the antibiotic may be given by mouth or by injection, or may be applied topically. Severe infections of the brain are usually treated with intravenous antibiotics. Sometimes, multiple antibiotics are used in case there is resistance to one antibiotic. Antibiotics only work for bacteria and do not affect viruses. Antibiotics work by slowing down the multiplication of bacteria or killing the bacteria. The most common classes of antibiotics used in medicine include penicillin, cephalosporins, aminoglycosides, macrolides, quinolones and tetracyclines.

Not all infections require treatment, and for many self-limiting infections the treatment may cause more side-effects than benefits. Antimicrobial stewardship is the concept that healthcare providers should treat an infection with an antimicrobial that specifically works well for the target pathogen for the shortest amount of time and to only treat when there is a known or highly suspected pathogen that will respond to the medication.

Large doses of glucocorticoids are the treatment of choice, and are administered until the signs have resolved. In uncomplicated cases, this can take up to a month. If dogs are not treated promptly and with high doses of steroids, severe scarring may occur. If there is evidence of secondary bacterial infection, treatment with antibiotics is required.

Among the categories of bacteria most known to infect patients are the category MRSA (resistant strain of "S. aureus"), member of gram-positive bacteria and "Acinetobacter" ("A. baumannii"), which is gram-negative. While antibiotic drugs to treat diseases caused by gram-positive MRSA are available, few effective drugs are available for "Acinetobacter". "Acinetobacter" bacteria are evolving and becoming immune to existing antibiotics, so in many cases, polymyxin-type antibacterials need to be used. "In many respects it’s far worse than MRSA," said a specialist at Case Western Reserve University.

Another growing disease, especially prevalent in New York City hospitals, is the drug-resistant, gram-negative "Klebsiella pneumoniae". An estimated more than 20% of the "Klebsiella" infections in Brooklyn hospitals "are now resistant to virtually all modern antibiotics, and those supergerms are now spreading worldwide."

The bacteria, classified as gram-negative because of their reaction to the Gram stain test, can cause severe pneumonia and infections of the urinary tract, bloodstream, and other parts of the body. Their cell structures make them more difficult to attack with antibiotics than gram-positive organisms like MRSA. In some cases, antibiotic resistance is spreading to gram-negative bacteria that can infect people outside the hospital. "For gram-positives we need better drugs; for gram-negatives we need any drugs," said Dr. Brad Spellberg, an infectious-disease specialist at Harbor-UCLA Medical Center, and the author of "Rising Plague", a book about drug-resistant pathogens.

One-third of nosocomial infections are considered preventable. The CDC estimates 2 million people in the United States are infected annually by hospital-acquired infections, resulting in 20,000 deaths. The most common nosocomial infections are of the urinary tract, surgical site and various pneumonias.

Treatments involve antibiotics that cover for "Pseudomonas aeruginosa". Antipseudomonal penicillins, aminoglycosides, fluoroquinolones, third generation cephalosporins or aztreonam can be given. Usually, the antibiotics are changed according to the culture and sensitivity result. In patients with very low white blood cell counts, Granulocyte-macrophage colony-stimulating factor may be given. Depending on the causal agents, antivirals or antifungals can be added.

Surgery will be needed if there is extensive necrosis not responding to medical treatments.

Treatment for gastroenteritis due to "Y. enterocolitica" is not needed in the majority of cases. Severe infections with systemic involvement (sepsis or bacteremia) often requires aggressive antibiotic therapy; the drugs of choice are doxycycline and an aminoglycoside. Alternatives include cefotaxime, fluoroquinolones, and co-trimoxazole.

Not all people with heart disease require antibiotics to prevent infective endocarditis. Heart diseases have been classified into high, medium and low risk of developing IE. Those falling into high risk category require IE prophylaxis before endoscopies and urinary tract procedures.

Diseases listed under high risk include:

1. Prior endocarditis

2. Unrepaired cyanotic congenital heart diseases

3. Completely repaired congenital heart disease in their first 6 months

4. Prosthetic heart valves

5. Incompletely repaired congenital heart diseases

6. Cardiac transplant valvulopathy

Following are the antibiotic regimens recommended by the American Heart Association for antibiotic prophylaxis:

In the UK, NICE clinical guidelines no longer advise prophylaxis because there is no clinical evidence that it reduces the incidence of IE and there are negative effects (e.g. allergy and increased bacterial resistance) of taking antibiotics that may outweigh the benefits.

Antibiotics were historically commonly recommended to prevent IE in those with heart problems undergoing dental procedures (known as dental antibiotic prophylaxis). They are less commonly recommended for this procedure.

Antibiotics to combat the streptococcal infection are the mainstay of treatment for scarlet fever. Prompt administration of appropriate antibiotics decreases the length of illness. Peeling of the outer layer of skin however will happen despite treatment. One of the main goals of treatment is to prevent the child from developing one of the suppurative or nonsuppurative complications, especially acute rheumatic fever. As long as antibiotics are started within 9 days, it is very unlikely for the child to develop acute rheumatic fever. Antibiotic therapy has not been shown to prevent the development of poststreptococcal glomerulonephritis. Another important reason for prompt treatment with antibiotics is the ability to prevent transmission of the infection between children. An infected individual is most likely to pass on the infection to another person during the first 2 weeks. A child is no longer contagious (able to pass the infection to another child) after 24 hours of antibiotics.

The antibiotic of choice is penicillin V which is taken by mouth in pill form. Children who are not able to take pills can be given amoxicillin which comes in a liquid form and is equally effective. Duration of treatment is 10 days. Benzathine Penicillin G can be given as a one time intramuscular injection as another alternative if swallowing pills is not possible. If the patient is allergic to the family of antibiotics which both penicillin and amoxicillin are a part of (beta-lactam antibiotics), a first generation cephalosporin is used. Cephalosporin antibiotics however can still cause adverse reactions in patients whose allergic reaction to penicillin is a Type 1 Hypersensitivity reaction. In those cases it is appropriate to choose clindamycin or erythromycin instead.

Tonsillectomy, although once a reasonable treatment for recurrent streptococcal pharyngitis, is not indicated. This is due to the fact that a person can still be infected with group A streptococcus without their tonsils.

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.

A number of other conditions can cause fevers following delivery including: urinary tract infections, breast engorgement, atelectasis and surgical incisions among others.

Treatment is supportive and based upon symptoms, with fluid and electrolyte replacement as the primary goal. Dehydration caused by diarrhea and vomiting is the most common complication. To prevent dehydration, it is important to take frequent sips of a rehydration drink (like water) or try to drink a cup of water or rehydration drink for each large, loose stool.

Dietary management of enteritis consists of starting with a clear liquid diet until vomiting and diarrhea end and then slowly introduce the BRATT diet. The BRATT diet consists of bananas, rice, applesauce, tea, and toast. It is also important to avoid foods that are high in fiber or are possibly difficult to digest.

The severity of this disease frequently warrants hospitalization. Admission to the intensive care unit is often necessary for supportive care (for aggressive fluid management, ventilation, renal replacement therapy and inotropic support), particularly in the case of multiple organ failure. The source of infection should be removed or drained if possible: abscesses and collections should be drained. Anyone wearing a tampon at the onset of symptoms should remove it immediately. Outcomes are poorer in patients who do not have the source of infection removed.

Antibiotic treatment should cover both "S. pyogenes" and "S. aureus". This may include a combination of cephalosporins, penicillins or vancomycin. The addition of clindamycin or gentamicin reduces toxin production and mortality.

The main organism associated with ecthyma gangrenosum is "Pseudomonas aeruginosa". However, multi-bacterial cases are reported as well. Prevention measures include practicing proper hygiene, educating the immunocompromised patients for awareness to avoid possible conditions and seek timely medical treatment.

Broadspectrum antibiotic to cover mixed flora is the mainstay of treatment. Pulmonary physiotherapy and postural drainage are also important. Surgical procedures are required in selective patients for drainage or pulmonary resection.

The mainstay of treatment for SSSS is supportive care along with eradication of the primary infection. Conservative measures include rehydration, antipyretics (e.g., ibuprofen, aspirin, and paracetamol), management of thermal burns, and stabilization. Parenteral antibiotics to cover "S. aureus" should be administered. Most strains of "S. aureus" implicated in SSSS have penicillinases, and are therefore penicillin resistant. Therefore, treatment with Nafcillin, oxacillin, or vancomycin is typically indicated. Clindamycin is sometimes also used because of its inhibition of exotoxins.

Antibiotic creams are the preferred treatment for mild cases of impetigo, despite their limited systemic absorption. Such prescribed ointments include neosporin, fusidic acid, chloramphenicol and mupirocin. More severe cases of impetigo however (especially bullous impetigo) will likely require oral agents with better systemic bioavailability, such as cephalexin. Cases that do not resolve with initial antibiotic therapy or require hospitalization may also be indicative an MRSA infection, which would require the use of agents specifically able to treat it, such as clindamycin.

Antibiotic treatment typically last 7–10 days, and although highly effective some cases of methicillin resistant S. aureus (MRSA) may require longer therapy depending on the severity of infection and how much it has spread.