Skin and skin structure infections in the patient at risk: carrier state of Staphylococcus aureus

Microbiome as a tool and a target in the effort to address antimicrobial resistance

Reciprocal, intimate relationships between the human microbiome and the host immune system are shaped by past microbial encounters and prepare the host for future ones. Antibiotics and other antimicrobials leave their mark on both the microbiome and host immunity. Antimicrobials alter the structure of the microbiota, expand the host-specific pool of antimicrobial-resistance genes and organisms, degrade the protective effects of the microbiota against invasion by pathogens, and may impair vaccine efficacy. Through these effects on the microbiome they may affect immune responses. Vaccines that exert protective or therapeutic effects against pathogens may reduce the use of antimicrobials, the development and spread of antimicrobial resistance, and the harmful impacts of these drugs on the microbiome. Other strategies involving manipulation of the microbiome to deplete antibiotic-resistant organisms or to enhance immune responses to vaccines may prove valuable in addressing antimicrobial resistance as well. This article describes the intersections of immunity, microbiome and antimicrobial exposure, and the use of vaccines and other alternative strategies for the control and management of antimicrobial resistance.

The Role of the Environment and Colonization in Healthcare-Associated Infections

Healthcare-associated infections (HAIs) can be caused by endogenous host microbial flora or by exogenous microbes, including those found in the hospital environment. Efforts to decrease endogenous pathogens via decolonization and skin antisepsis may decrease the risk of infection in some settings. Controlling the spread of potential pathogens from the environment requires meticulous attention to cleaning and disinfection practices. In addition to selection of the appropriate cleaning agent, use of tools that assess the adequacy of cleaning and addition of no-touch cleaning technology may decrease environmental contamination. Hand hygiene is also a critical component of preventing transmission of pathogens from the environment to patients via healthcare worker hands.

Identification of nucleoid associated proteins (NAPs) under oxidative stress in Staphylococcus aureus

Background

Bacterial nucleoid consists of genome DNA, RNA, and hundreds of nucleoid-associated proteins (NAPs). Escherichia coli nucleoid is compacted towards the stationary phase, replacing most log-phase NAPs with the major stationary-phase nucleoid protein, Dps. In contrast, Staphylococcus aureus nucleoid sustains the fiber structures throughout the growth. Instead, the Dps homologue, MrgA, expresses under oxidative stress conditions to clump the nucleoid, but the composition of the clumped nucleoid was elusive.

Results

The staphylococcal nucleoid under oxidative stress was isolated by sucrose gradient centrifugation, and the proteins were analyzed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). We identified 299 proteins in the nucleoid under oxidative stress, including 113 csNAPs (contaminant-subtracted NAPs). Comparison with the previously identified csNAPs in log- and stationary phase indicated that one fifth of the csNAPs under oxidative stress were the constitutive nucleoid components; importantly, several factors including HU, SarA, FabZ, and ribosomes were sustained under oxidative stress. Some factors (e.g. SA1663 and SA0092/SA0093) with unknown functions were included in the csNAPs list specifically under oxidative stress condition.

Conclusion

Nucleoid constitutively holds Hu, SarA, FabG, and ribosomal proteins even under the oxidative stress, reflecting the active functions of the clumped nucleoid, unlikely to the dormant E. coli nucleoid compacted in the stationary phase or starvation.

Electronic supplementary material

The online version of this article (10.1186/s12866-017-1114-3) contains supplementary material, which is available to authorized users.

Surgical Site Infections: An Update

Surgical site infections (SSIs) lead to adverse patient outcomes, including prolonged hospitalization and death. Wound contamination occurs with each incision, but proven strategies exist to decrease the risk of SSI. In particular, improved adherence to evidence-based preventative measures related to appropriate antimicrobial prophylaxis can decrease the rate of SSI. Aggressive surgical debridement and effective antimicrobial therapy are needed to optimize the treatment of SSI.

Chronic wound infections: the role of Pseudomonas aeruginosa and Staphylococcus aureus

Chronic leg ulcers affect 1-2% of the general population and are related to increased morbidity and health costs. Staphylococcus aureus and Pseudomonas aeruginosa are the most common bacteria isolated from chronic wounds. They can express virulence factors and surface proteins affecting wound healing. The co-infection of S. aureus and P. aeruginosa is more virulent than single infection. In particular, S. aureus and P. aeruginosa have both intrinsic and acquired antibiotic resistance, making clinical management of infection a real challenge, particularly in patients with comorbidity. Therefore, a correct and prompt diagnosis of chronic wound infection requires a detailed knowledge of skin bacterial flora. This is a necessary prerequisite for tailored pharmacological treatment, improving symptoms, and reducing side effects and antibiotic resistance.

Breast abscess, an early indicator for diabetes mellitus in non-lactating women: a retrospective study from rural India

INTRODUCTION

Breast abscess is commonly seen in lactating and non-lactating women. Diabetes mellitus (DM) frequently predisposes to soft tissue infections and has many different presentations. But DM presenting in the form of breast abscess is yet to be studied, and we believe our study is the first to explore this connection.

METHODS

We collected 30 cases of breast abscess in women who presented to our hospital from May 2010 to June 2011 retrospectively. They were classified into lactating and non-lactating women, and their glycemic status was evaluated, together with length of hospital stay, management, recurrence, and follow-up status after 6 months.

RESULTS

We found that of the 30 patients in our study, 20% had high blood sugar levels. And 37.5% of the non-lactating women were diagnosed newly with DM.

CONCLUSIONS

This study shows that DM can present as breast abscess in non-lactating women. Therefore, non-lactating women with a breast abscess should be evaluated for DM.

Reduced neutrophil apoptosis in diabetic mice during staphylococcal infection leads to prolonged Tnfα production and reduced neutrophil clearance

Diabetes is a frequent underlying medical condition among individuals with Staphylococcus aureus infections, and diabetic patients often suffer from chronic inflammation and prolonged infections. Neutrophils are the most abundant inflammatory cells during the early stages of bacterial diseases, and previous studies have reported deficiencies in neutrophil function in diabetic hosts. We challenged age-matched hyperglycemic and normoglycemic NOD mice intraperitoneally with S. aureus and evaluated the fate of neutrophils recruited to the peritoneal cavity. Neutrophils were more abundant in the peritoneal fluids of infected diabetic mice by 48 h after bacterial inoculation, and they showed prolonged viability ex vivo compared to neutrophils from infected nondiabetic mice. These differences correlated with reduced apoptosis of neutrophils from diabetic mice and were dependent upon the presence of S. aureus and a functional neutrophil respiratory burst. Decreased apoptosis correlated with impaired clearance of neutrophils by macrophages both in vitro and in vivo and prolonged production of proinflammatory tumor necrosis factor alpha by neutrophils from diabetic mice. Our results suggest that defects in neutrophil apoptosis may contribute to the chronic inflammation and the inability to clear staphylococcal infections observed in diabetic patients.

Prevention of chronic furunculosis with low‐dose azithromycin

BACKGROUND

Chronic furunculosis is a recurrent staphylococcal abscess of the hair follicle. Besides ensuring personal hygiene, the management consists of long-term treatment with topical and systemic antibiotics.

OBJECTIVE

An open-labeled, prospective study was conducted to assess the clinical and in vitro efficacy of azithromycin in the long-term suppressive treatment of chronic furunculosis.

METHODS

Patients with a history of three or more episodes of furuncles were assigned to receive 12 weeks of suppressive treatment with azithromycin at a weekly dosage of 500 mg. In vitro susceptibility of azithromycin was evaluated with E-test. The primary efficacy parameter was complete absence of furuncles during the 3 months of azithromycin treatment. The secondary efficacy parameter was further absence of furuncles during the 3-month follow-up period.

RESULTS

At the end of 3 months of therapy, azithromycin was found to be effective in 19 (79.2%) of 24 patients; 18 of these patients remained in remission during the 3 months of follow-up. All of the strains were methicillin-sensitive. The results of the E-test showed that 15 of 18 strains (83.3%) were susceptible to azithromycin.

CONCLUSION

The results of this study indicate that azithromycin is an effective and safe alternative in the treatment of chronic furunculosis caused by methicillin-sensitive Staphylococcus aureus.

Staphylococcal surgical site infections

Staphylococcus aureus is the leading cause of surgical site infections (SSI) in the United States. In particular, SSI caused by methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a devastating complication, leading to increased mortality rates, increased length of hospitalization, and increased costs. Proven strategies for prevention of SSI caused by S aureus include addressing modifiable risk factors and correct choice and timing of antimicrobial prophylaxis. Other strategies, including decolonization and the use of vancomycin, remain controversial.

The emergence of meticillin-resistant Staphylococcus aureus among injecting drug users

OBJECTIVE

To quantify an observed increase in meticillin-resistant Staphylococcus aureus (MRSA) infections in injecting drug users (IDUs) and, using genetic analysis and clinical presentation, contrast findings with those from previous studies in Brighton to further understanding of the clinical epidemiology and underlying molecular biology associated with the increase.

METHODS

From 2006 to 2008, isolates of S. aureus were collected, together with clinical details from infected IDUs. Isolates were characterised using antibiotic susceptibilities, multilocus-sequence typing (MLST) and spa typing. The molecular epidemiology and patterns of clinical presentation were compared with results from 1999-2000 to 2000-2003.

RESULTS

From 2006 to 2008, 18/37 (49%) of clinical isolates from IDUs were MRSA compared with 4/59 (7%) in 2000-2003 and 0/48 (0%) in 1999-2000. Despite this increase, hospital attendances by IDUs for treatment of infection dropped from 3.2 to 1.1 patients per month. MLST showed a shift in population structure towards a single MRSA clone, ST1, rather than epidemic hospital-associated strains.

CONCLUSION

In IDUs between 2000-2003 and 2006-2008, an increase occurred in the percentage of community-associated S. aureus isolates showing meticillin-resistance, but hospital attendances decreased. IDUs may act as a focus for the emergence of resistant S. aureus strains.

Skin and Soft Tissue Infections in Older Adults

Skin and soft tissue infections (SSTIs) are a common cause of morbidity in older patients. Because of changes in skin consistency, immunosenescence, and the presence of underlying skin conditions and comorbid conditions, elderly persons are at high risk for SSTIs. Specific community- and hospital-associated SSTIs are reviewed in this article with particular emphasis on the epidemiology, prevention, risk factors, and treatment of SSTIs in older patients.

Increased risk of common infections in patients with type 1 and type 2 diabetes mellitus

BACKGROUND

Clinical data on the association of diabetes mellitus with common infections are virtually lacking, not conclusive, and often biased. We intended to determine the relative risks of common infections in patients with type 1 and type 2 diabetes mellitus (DM1 and DM2, respectively).

METHODS

In a 12-month prospective cohort study conducted as part of the Second Dutch National Survey of General Practice, we compared 705 adult patients who had DM1 and 6712 adult patients who had DM2 with 18,911 control patients who had hypertension without diabetes. Outcome measures were medically attended episodes of infection of the respiratory tract, urinary tract, and skin and mucous membranes. We applied multivariable and polytomous logistic regression analysis to determine independent risks of infections and their recurrences in patients with diabetes, compared with control patients.

RESULTS

Upper respiratory infections were equally common among patients with diabetes and control patients. Patients with diabetes had a greater risk of lower respiratory tract infection (for patients with DM1: adjusted odds ratio [AOR], 1.42 [95% confidence interval {CI}, 0.96-2.08]; for patients with DM2: AOR, 1.32 [95% CI, 1.13-1.53]), urinary tract infection (for patients with DM1: AOR, 1.96 [95% CI, 1.49-2.58]; for patients with DM2: AOR, 1.24 [95% CI, 1.10-1.39]), bacterial skin and mucous membrane infection (for patients with DM1: AOR, 1.59 [95% CI, 1.12-2.24]; for patients with DM2: AOR, 1.33 [95% CI, 1.15-1.54]), and mycotic skin and mucous membrane infection (for patients with DM1: AOR, 1.34 [95% CI, 0.97-1.84]; for patients with DM2: AOR, 1.44 [95% CI, 1.27-1.63]). Risks increased with recurrences of common infections.

CONCLUSIONS

Patients with DM1 and DM2 are at increased risk for lower respiratory tract infection, urinary tract infection, and skin and mucous membrane infection. Studies are warranted into management of such infections in patients with diabetes.

Infections in diabetes

Diabetics are predisposed to infections because of various immune deficiencies, including neutrophil and monocyte dysfunction. Some of these immune deficiencies are improved by tight glucose control. This article is a review of the immune deficiencies seen in diabetes and an overview of selected infections that are commonly or predominantly seen in diabetics.

Guidelines for the management of intravascular catheter-related infections

These guidelines from the Infectious Diseases Society of America (IDSA), the American College of Critical Care Medicine (for the Society of Critical Care Medicine), and the Society for Healthcare Epidemiology of America contain recommendations for the management of adults and children with, and diagnosis of infections related to, peripheral and nontunneled central venous catheters (CVCs), pulmonary artery catheters, tunneled central catheters, and implantable devices. The guidelines, written for clinicians, contain IDSA evidence-based recommendations for assessment of the quality and strength of the data. Recommendations are presented according to the type of catheter, the infecting organism, and the associated complications.

Intravascular catheter-related infections are a major cause of morbidity and mortality in the United States. Coagulase-negative staphylococci,Staphylococcus aureus, aerobic gram-negative bacilli, andCandida albicansmost commonly cause catheter-related bloodstream infection. Management of catheter-related infection varies according to the type of catheter involved. After appropriate cultures of blood and catheter samples are done, empirical iv antimicrobial therapy should be initiated on the basis of clinical clues, the severity of the patient's acute illness, underlying disease, and the potential pathogen (s) involved. In most cases of nontunneled CVC-related bacteremia and fungemia, the CVC should be removed.

Epidemic spread of a single clone of methicillin-resistant Staphylococcus aureus among injection drug users in Zurich, Switzerland

We describe an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) among injection drug users (IDUs). From August 1994 through December 1999, we registered 31 IDUs with MRSA infections (12 with soft-tissue infection, 7 with pneumonia [fatal in 1], 7 with endocarditis [fatal in 1], 2 with osteomyelitis, 2 with septic arthritis, and 1 with ulcerative tonsillitis), with a marked increase in the number of IDUs registered during 1998 and 1999. Of 31 patients, 15 (48%) were infected with human immunodeficiency virus. A point-prevalence study among IDUs who frequented outpatient facilities in Zurich revealed an MRSA carriage rate of 10.3% (range, 0%-28.6%) in various facilities. In all but 1 case, pulsed-field gel electrophoresis banding patterns of isolates obtained from these patients were indistinguishable from isolates of the initial 31 IDUs registered. Risk factors for MRSA carriage were disability and prior hospitalization in a hospice. In summary, MRSA became endemic in IDUs in Zurich as a result of the spread of a single clone. This clone caused major morbidity and was responsible for a lethal outcome in 2 cases.

[Staphylococcus nasal carriage and infection of central venous ports in oncology]

OBJECTIVE

To assess the risk of infection of either subcutaneously implanted central venous access devices or percutaneous central venous catheters inserted via a subcutaneous tunnel in cancer patients with a positive staphylococcal nasal carriage.

STUDY DESIGN

Prospective study.

PATIENTS

The study included 266 patients undergoing cancer chemotherapy.

METHOD

A nasal swab was taken prior to insertion of the venous access device and the patients were followed over 30 days for the occurrence of a staphylococcal infection (hemoculture and device or site of insertion).

RESULTS

A nasal staphylococcal nasal carriage was found in 227 patients. Out of the 15 developing a device infection, a staphylococcal nasal colonization was existing in nine patients. Bacteriological screening a sensitivity of 60% and a specificity of 13%.

CONCLUSION

Bacteriological screening at the time of device insertion of a central venous access device is of no value for the detection of patients at risk of staphylococcal infection of the device.

Head-injured patients who are nasal carriers of Staphylococcus aureus are at high risk for Staphylococcus aureus pneumonia

OBJECTIVE

To determine if head-injured patients with premorbid nasal colonization with Staphylococcus aureus are at increased risk for S. aureus infection.

DESIGN

Patients admitted over a 2-yr period were enrolled if they met the following criteria: Injury Severity Score > or = 9, intensive care unit (ICU) admission, hospitalization in another hospital < 24 hrs, no recent use of antibiotics.

SETTING

Acute care trauma facility.

PATIENTS

Any patient sustaining acute, blunt, or penetrating injury and meeting the enrollement criteria were eligible.

INTERVENTIONS

Swab cultures of both internal nares were performed within 72 hrs of readmission and cultured for S. Aureus. Patients were prospectively monitored for S. Aureus infections until discharge.

MEASUREMENTS AND MAIN RESULTS

Admission nasal cultures were positive (NC+) for S. aureus in 144 of the 776 patients cultured. Forty of the 144 NC+ patients had isolated head (37) or high cervical spine (3) injury, and 11 of that group (27.5%) developed S. aureus infections. The remaining 104 patients positive for S. aureus on admission had no head injury (74) or head combined with torso and extremity injuries (30). S. aureus infection was diagnosed in 11 of the 104 patients (10.6%). The difference in incidence of infections is significant (p <.01), as is the difference in incidence of pneumonia (20% vs. 3.8%, respectively [p <.01]). Organisms causing pneumonia were often the same organisms isolated from the nares on admission.

CONCLUSIONS

Nasal colonization with S. aureus at the time of severe head injury increases the risk of S. aureus pneumonia during hospitalization. Prophylactic measures against S. aureus pneumonia may help reduce the length and cost of hospitalization.

Incidence of postoperative infection or positive culture after facial laser resurfacing: a pilot study, a case report, and a proposal for a rational approach to antibiotic prophylaxis

BACKGROUND

Laser skin resurfacing (LSR) has emerged as a popular procedure for facial rejuvenation; however, there are no clear guidelines regarding systemic antibiotic prophylaxis.

OBJECTIVE

We attempt to provide practical guidelines for antibiotic prophylaxis in LSR based on our experiences, pharmacology, and a review of the literature.

METHODS

In a pilot study, four consecutive full-face LSR patients were treated without oral or topical antibiotics. The next four patients received oral prophylaxis with a narrow spectrum antibiotic. We also report the case of a severe gram-negative infection after LSR.

RESULTS

For full-face LSR, 2 of 4 consecutive patients without antibiotic prophylaxis experienced focal Staphylococcus aureus infection. The next 4 consecutive patients, who had received gram-positive oral prophylaxis, were all culture negative after 2 days. All test sites (5 of 5) were culture negative despite the absence of systemic or topical antibiotics. One patient not in the pilot study receiving gram-positive antibiotic prophylaxis experienced a gram-negative infection.

CONCLUSION

We recommend narrow-spectrum gram-positive oral antibiotic coverage for full-face and regional LSR.

Staphylococcus aureus nasal colonization in HIV-seropositive and HIV-seronegative drug users

Nasal colonization plays an important role in the pathogenesis of Staphylococcus aureus infections. To identify characteristics associated with colonization, we studied a cross-section of a well-described cohort of HIV-seropositive and -seronegative active and former drug users considered at risk for staphylococcal infections. Sixty percent of the 217 subjects were Hispanic, 36% were women, 25% actively used injection drugs, 23% actively used inhalational drugs, 23% received antibiotics, and 35% were HIV-seropositive. Forty-one percent of subjects had positive nasal cultures for S. aureus. The antibiotic susceptibility patterns were similar to the local hospital's outpatient isolates and no dominant strain was identified by arbitrarily primed polymerase chain reaction (AB-PCR). Variables significantly and independently associated with colonization included antibiotic use (odds ratio [OR] = 0.37; confidence interval [CI] = 0.18-0.77), active inhalational drug use within the HIV-seropositive population (OR = 2.36; CI = 1.10-5.10) and female gender (OR = 1.97; CI = 1.09-3.57). Characteristics not independently associated included injection drug use, HIV status, and CD4 count. The association with active inhalational drug use, a novel finding, may reflect alterations in the integrity of the nasal mucosa. The lack of association between HIV infection and S. aureus colonization, which is contrary to most previous studies, could be explained by our rigorous control for confounding variables or by a limited statistical power due to the sample sizes.

Nasal carriage of Staphylococcus aureus: epidemiology, underlying mechanisms, and associated risks

Staphylococcus aureus has long been recognized as an important pathogen in human disease. Due to an increasing number of infections caused by methicillin-resistant S. aureus (MRSA) strains, therapy has become problematic. Therefore, prevention of staphylococcal infections has become more important. Carriage of S. aureus appears to play a key role in the epidemiology and pathogenesis of infection. The ecological niches of S. aureus are the anterior nares. In healthy subjects, over time, three patterns of carriage can be distinguished: about 20% of people are persistent carriers, 60% are intermittent carriers, and approximately 20% almost never carry S. aureus. The molecular basis of the carrier state remains to be elucidated. In patients who repeatedly puncture the skin (e.g., hemodialysis or continuous ambulatory peritoneal dialysis [CAPD] patients and intravenous drug addicts) and patients with human immunodeficiency virus (HIV) infection, increased carriage rates are found. Carriage has been identified as an important risk factor for infection in patients undergoing surgery, those on hemodialysis or CAPD, those with HIV infection and AIDS, those with intravascular devices, and those colonized with MRSA. Elimination of carriage has been found to reduce the infection rates in surgical patients and those on hemodialysis and CAPD. Elimination of carriage appears to be an attractive preventive strategy in patients at risk. Further studies are needed to optimize this strategy and to define the groups at risk.

Current aspects of bacterial infections of the skin

The practicing dermatologist is faced with an ever-changing epidemiologic spectrum of cutaneous bacterial diseases. Studies have stated that bacterial skin infections may account for up to 17% of clinical visits. It is hoped that the information presented in this article will enable the practicing dermatologist to provide improved patient care in the diagnosis and management of bacterial infections of the skin.

Effect of rifampin on Staphylococcus aureus colonization in children on chronic peritoneal dialysis

The efficacy of rifampin in eliminating Staphylococcus aureus colonization was evaluated in a pediatric peritoneal dialysis population. Six children with documented nasal colonization were treated for 7 days with rifampin and cloxacillin. Although antimicrobial therapy eliminated nasal carriage in all patients, recolonization occurred in 66%. Exit site colonization proved difficult to eradicate with negative cultures documented in only 3 of 5 children after rifampin/cloxacillin therapy. Although S. aureus carriage is a risk factor for S. aureus infections, efforts to eradicate carriage with rifampin are hindered by rapid recolonization.

Long-term complications of diabetes mellitus, Part II: Gastrointestinal and infectious

Numerous gastrointestinal and infectious diseases are associated with long-standing and often poorly controlled DM in humans. Although not as well documented in veterinary patients, the veterinary practitioner must always have an index of suspicion for the possibility of these complications. Because the clinical signs of a number of these problems are identical, proper diagnostic procedures need to be used to differentiate among the gastrointestinal and even infectious problems. In all cases, stringent blood glucose control is the common denominator in effective treatment. Other agents can be used both to assist in short-term control and for long-term therapy.

Impetigo: an overview

This article reviews in detail the pathogenesis, clinical characteristics and management of impetigo in children. Impetigo is the most common bacterial skin infection of children. Most cases of nonbullous impetigo and all cases of bullous impetigo are caused by Staphylococcus aureus. The remainder of cases of nonbullous impetigo are due to group A beta hemolytic streptococci (GABHS). GABHS colonize the skin directly by binding to sites on fibronectin that are exposed by trauma. In contrast, S. aureus colonizes the nasal epithelium first; from this reservoir, colonization of the skin occurs. Patients with recurrent impetigo should be evaluated for carriage of S. aureus. Superficial, localized impetigo may be treated successfully in more than 90% of cases with topical application of mupirocin ointment. Impetigo that is widespread or involves deeper tissues should be treated with a beta-lactamase-resistant oral antibiotic. The choice of antibiotics is affected by the local prevalence of resistance to erythromycin among strains of S. aureus, antibiotic cost and availability, and issues of compliance.

Case report: diabetes mellitus as a predisposing factor in the development of pyomyositis

Pyomyositis is an uncommon infection in temperate climates, usually resulting from Staphylococcus aureus infection of skeletal muscle. In this report, the authors describe a patient with untreated Type 2 diabetes mellitus who suffered nonpenetrating blunt trauma to his left anterior thigh, and S. aureus pyomyositis and secondary osteomyelitis of his proximal tibia and patella subsequently developed as a result of delayed diagnosis and treatment. Patients with diabetes mellitus are at increased risk for the development of pyomyositis because of more frequent S. aureus colonization of skin, nasal mucosa, and oropharynx; a delay in definitive treatment can lead to significant morbidity in these patients. Computed tomography or magnetic resonance imaging may be helpful in the diagnosis of pyomyositis. An anemia of chronic disease may result from this disorder, which resolves with treatment.

Staphylococcus aureus pericarditis in HIV-infected patients

Serious infections caused by Staphylococcus aureus in HIV-infected patients have been reported. Contributing factors in the development of invasive S aureus infections include a high rate of skin and nasal colonization, frequent dermatologic disease, and the use of intravenous catheters. The authors report three cases of S aureus pericarditis in HIV-infected patients. While cases of viral, mycobacterial, and malignant pericardial effusions in HIV-infected patients have been reported, a review of the literature disclosed only three cases of bacterial pericarditis. Despite appropriate antibiotic therapy and drainage, a patient's condition may abruptly deteriorate and progress to tamponade. Early recognition of bacteremia and pericarditis and monitoring for cardiac tamponade, along with aggressive treatment, can result in a favorable outcome, but mortality remains high, particularly when S aureus is the causative agent.

Nasal carriage of methicillin-resistant Staphylococcus aureus by hospital staff in north Jordan

The nasal carriage of methicillin-resistant Staphylococcus aureus was detected in 550 hospital staff members of four hospitals in north Jordan. Of the 109 (19.8%) individuals tested who were nasal carriers of S. aureus, only 32 (5.8%) were found to be carriers of methicillin-resistant Staphylococcus aureus. The carriers were four doctors, 23 nurses, three laboratory technicians, one maid and an administrator. It was noted that 25 (78.1%) of these carriers were in constant contact with patients in operating theatres, surgical wards or intensive care units. It was not clear whether the carriers were short- or long-term carriers, or whether they were persistent sources of methicillin-resistant Staphylococcus aureus. Decontamination of these carriers was considered among other control measures to avoid the dangerous outcome of hospital outbreaks caused by this potential pathogen.

Microbiology of the skin: resident flora, ecology, infection

Humans exist in an environment replete with microorganisms, but only a few become resident on the skin surface. The skin possesses protective mechanisms to limit colonization, and the survival of organisms on the surface lies in part in the ability of the organisms to resist these mechanisms. Microbial colonization on the skin adds to the skin's defense against potentially pathogenic organisms. Although microbes normally live in synergy with their hosts, occasionally colonization can result in clinical infection. Common infections consist of superficial infections of the stratum corneum or appendageal structures that can respond dramatically to therapy but commonly relapse. In rare circumstances, these infections can be quite severe, particularly in immunocompromised patients or in hospitalized patients with indwelling foreign devices. These infections are often resistant to conventional antibiotics and can result in infection with other opportunistic pathogens.

Problems of intensive therapy in childhood cancer

Tremendous progress has been made in the treatment of childhood cancers. Certain hematologic malignancies have an impressive cure rate with the current intensive antineoplastic treatment regimens. There is optimism that the treatment of children who have advanced stage solid tumors with intensive, multimodality therapy may improve their chances for long-term survival. These treatment programs, though potentially curative, are highly toxic, with severe myelosuppression and damage to other organ systems. An awareness of these potential toxicities, an understanding of how to prevent or minimize certain problems, and the ability to treat those complications which do arise are all essential to the successful management of childhood cancer.

Gastrointestinal carriage of methicillin-resistant Staphylococcus aureus

Nasal and rectal cultures were taken from all patients with methicillin-resistant Staphylococcus aureus identified on routine cultures obtained because of clinical indications. Of 117 patients studied over a 3-year period, 70 (60%) had rectal colonization and 62 (53%) had nasal colonization. Rectal colonization, probably reflecting gastrointestinal carriage, may be a source of transmission of methicillin-resistant S. aureus in hospitalized patients and may be difficult to eradicate.