Human isolates of Staphylococcus caprae: association with bone and joint infections

A capricious case of Staphylococcus caprae thoracic osteomyelitis

Staphylococcus caprae (S. caprae) is a gram positive, coagulase-negative Staphylococci (CoNS) that occurs as a commensal pathogen on the human skin. It recently has been recognized in causing nosocomial infections involving the bloodstream, urinary tract, heart, bone, and joints, particularly in immunosuppressed patients or individuals with prosthetic devices. Previously, S. caprae was underreported as it was difficult to identify in the clinical microbiology laboratory; however, due to advances in molecular identification methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), more clinical cases are being identified in human isolates and appropriately treated. S. caprae osteoarticular infections are usually associated with polymicrobial infections and presence of orthopedic prostheses in immunocompromised adults. This pathogen has an even rarer presentation of bone and joint infections (BJIs) in immunocompetent individuals without orthopedic devices. Our case is of a 65-year-old immunocompetent male with diet-controlled diabetes mellitus type 2 and end-stage renal disease (ESRD) on hemodialysis who presented with worsening mid-thoracic pain after a ground-level fall and was diagnosed with biopsy-proven S. caprae thoracic discitis/osteomyelitis, associated with recurrent catheter-related bloodstream infection (CRBSI). It illustrates the importance of recognizing S. caprae as an emerging human pathogen, even in immunocompetent individuals without orthopedic hardware, requiring prompt targeted treatment of native BJIs to prevent unfavorable outcomes.

Subacute osteomyelitis due to Staphylococcus caprae in a teenager: A case report and review of the literature

BACKGROUND

Staphylococcus caprae (S. caprae) is a human commensal bacterium which can be detected in the nose, nails, and skin. It can be responsible for heterogeneous infections such as bacteremia, endocarditis, pneumonia, acute otitis externa, peritonitis, and urinary tract infections. Bone and joint infections due to S. caprae have also been reported, but most of them resulted from the infection of orthopedic devices, especially joint prostheses and internal osteosynthesis devices. Rare cases of primary osteoarticular infections caused by S. caprae have been described, including osteitis, arthritis, or spondylodiscitis.

CASE SUMMARY

We report an unusual case of subacute osteomyelitis in a toe phalanx caused by S. caprae in a 14.5-year-old girl.

CONCLUSION

Subacute S. caprae osteomyelitis is a little-known and probably underestimated community-acquired infectious disease. This microorganism’s pathogenicity should be seen as more than a classic nosocomial orthopedic device infection.

Subacute osteomyelitis due to Staphylococcus caprae in a teenager: A case report and review of the literature

BACKGROUND

Staphylococcus caprae (S. caprae) is a human commensal bacterium which can be detected in the nose, nails, and skin. It can be responsible for heterogeneous infections such as bacteremia, endocarditis, pneumonia, acute otitis externa, peritonitis, and urinary tract infections. Bone and joint infections due to S. caprae have also been reported, but most of them resulted from the infection of orthopedic devices, especially joint prostheses and internal osteosynthesis devices. Rare cases of primary osteoarticular infections caused by S. caprae have been described, including osteitis, arthritis, or spondylodiscitis.

CASE SUMMARY

We report an unusual case of subacute osteomyelitis in a toe phalanx caused by S. caprae in a 14.5-year-old girl.

CONCLUSION

Subacute S. caprae osteomyelitis is a little-known and probably underestimated community-acquired infectious disease. This microorganism's pathogenicity should be seen as more than a classic nosocomial orthopedic device infection.

A Rare Case of Staphylococcus caprae-Caused Periprosthetic Joint Infection Following Total Hip Arthroplasty: A Literature Review and Antibiotic Treatment Algorithm Suggestion

In this study, we discuss a case of a 59-year-old male who developed a periprosthetic joint infection (PJI) three months after a total hip arthroplasty (THA). The patient complained of groin and buttock pain, swelling, and high temperature. A palpable fluid collection, discomfort, edema, and elevated local temperature were present in the clinical examination. Laboratory analysis revealed elevated white blood cells, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The preoperative joint aspiration came up positive for Staphylococcus caprae (S. caprae) infection. Diagnosis and pathogen identification were confirmed by histological examination of six tissue samples obtained during surgery. We initially performed early debridement, antibiotics, and implant retention (DAIR) followed by antibiotic therapy suggested by an infectious disease specialist. DAIR failed two months later, and we proceeded to a two-stage revision. Following surgery, the patient was treated with intravenous antibiotic combination therapy for three weeks and thereafter with oral antibiotics for three months. Four months down the line, the patient is free of symptoms, and the inflammatory markers are normal. Finally, we will proceed with the second stage of revision. This study highlights a very rare case of PJI infection by S. caprae, reviews the limited literature, and provides the available evidence for surgical and antibiotic management.

Antibiotic Stewardship in Treatment of Osteoarticular Infections Based on Local Epidemiology and Bacterial Growth Times

Incubation for 14 days is recommended for the culture of microorganisms from osteoarticular infections (OAI), but there are no recommendations for postoperative antibiotic stewardship concerning empirical antimicrobial therapy (EAT), while prolonging broad-spectrum EAT results in adverse effects. The aim of this study was to describe the local OAI epidemiology with consideration of bacterial growth times to determine which antibiotic stewardship intervention should be implemented in cases of negative culture after 2 days of incubation. We performed a 1-year, single-center, noninterventional cohort study at the Pitié-Salpêtrière hospital OAI reference center. Samples were taken as part of the local standard of care protocol for adult patients who underwent surgery for OAI (native or device related) and received EAT (i.e., piperacillin-tazobactam plus daptomycin [PTD]) following surgery. The time to culture positivity was monitored daily. Overall, 147 patients were recruited, accounting for 151 episodes of OAI, including 112 device-related infections. Microbiological cultures were positive in 144 cases, including 42% polymicrobial infections. Overall, a definitive microbiological result was obtained within 48 h in 118 cases (78%) and within 5 days in 130 cases (86%). After 5 days, only Gram-positive bacteria were recovered, especially Cutibacterium acnes, Staphylococcus spp., and Streptococcus spp. Overall, 90% of culture-positive OAI were correctly treated with the locally established EAT. EAT guidance for OAI was in agreement with our local epidemiology. Our results supported antibiotic stewardship intervention consisting of stopping piperacillin-tazobactam treatment at day 5 in cases of negative culture. IMPORTANCE Osteoarticular infections (OAI) remain challenging to diagnose and to treat. One of the issues concerns postoperative empirical antimicrobial therapy (EAT), which is usually a combination of broad-spectrum antibiotics. This EAT is maintained up to 2 weeks, until the availability of the microbiological results (identification and drug susceptibility testing of the microorganisms responsible for the OAI). Our results provide new data that will help to improve OAI management, especially EAT. Indeed, we have shown that antibiotic stewardship intervention consisting of stopping the antibiotic targeting Gram-negative bacteria included in the EAT could be implemented in cases where culture is negative after 5 days of incubation. The benefits of such an antibiotic stewardship plan include improved patient outcomes, reduced adverse events (including Clostridioides difficile infection), improvement in rates of susceptibilities to targeted antibiotics, and optimization of resource utilization across the continuum of care.

A Potential Predictive Role of the Scalp Microbiome Profiling in Patients with Alopecia Areata: Staphylococcus caprae, Corynebacterium, and Cutibacterium Species

Little is known about the scalp bacterial composition of alopecia areata (AA) patients. The aim of this study was to investigate the differences in the scalp microbiome of AA patients according to their prognosis, in addition to healthy controls. A total of 33 AA patients and 12 healthy controls (HC) were included in this study. The microbiomes were characterized by sequencing 16S rRNA genes on the Illumina MiSeq platform. The scalp microbiome was more diverse in AA patients compared to HC, but not significantly different according to the severity of AA. Nevertheless, the higher proportion of Corynebacterium species and the lower proportion of Staphylococcus caprae among the Staphylococcus species were noticed in severe AA patients compared to HC or mild AA. The higher ratio of Cutibacterium species to S. caprae was noticed in severe AA. We highlight the potential predictive role of scalp microbiome profiling to a worse prognosis of patients with alopecia areata.

A Rare Case of Extremely Severe Heterotopic Ossification after Primary Total Hip Arthroplasty due to Persistent Mild Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) caused by coagulase-negative staphylococci (CNS) can be a mild, persisting infection. Although heterotopic ossification (HO) is common following total hip arthroplasty (THA), the etiology of severe HO remains unclear. Herein, we describe a rare case of extremely severe HO after a PJI associated with a Staphylococcus caprae infection in a 78-year-old male patient. The patient had poorly controlled diabetes mellitus with no diabetic complications. The patient had no previous history of hip surgery, hip injury, or systemic bacterial infection. Immediately after the initial THA, he developed intermittent low-grade fever (37°C), which persisted for 3 months; consequently, he also reported mild hip pain during walking. He experienced a gradual decrease in hip range of motion within 5 years after the surgery, with progressive gait impairment. Two revision surgeries were required for the successful treatment of this difficult case. The patient's hip function improved, and the PJI was controlled following the second revision surgery. Based on the clinical course, CNS-caused PJI may lead to severe HO. This possibility warrants verification from an accumulated number of cases.

A rare lumbar pyogenic spondylodiscitis caused by staphylococcus caprae with initial misdiagnosis: case report and literature review

Background

Staphylococcus caprae (Sc) is an uncommon causative organism for human. Lumbar pyogenic spondylodiscitis (LPS) of Sc is extremely rare and only a few cases have been reported. As far as we know, there is no specific literature on the diagnosis and treatment for LPS of Sc with L5 nerve root irritation.

Case presentation

A 65-year-old male patient complained of chronic low back pain for 10 years, acute worsening with radiating pain to left lower extremity over a month. Physical examination revealed tenderness point on his low back, 3/5 dorsiflexor strength in his left 1st toe and decreased sensation of pin prick over the left lateral shank and medial dorsal foot. The individual was initially misdiagnosed with lumbar disc herniation (LDH) without further examination in outpatient, which was then found to be LPS of Sc with L5 nerve root irritation after admission to our hospital. Magnetic resonance images (MRI) of lumbar spine exhibited inflammation signal at L4-L5 level of the vertebral body and disc with hypointense on T1-weighted images (T1-WI) and hyperintense on T2-weighted images (T2-WI). The causative organism was confirmed by the culture of irrigation fluid obtained from L5 vertebrae by needle puncture. After systemic conservative treatment including using sensitive antimicrobial agents and immobilization, the rare infection was finally cured. The patient also showed a satisfactory recovery during the 36-month follow-up period.

Conclusions

Confirming the diagnosis and identifying the causative organism as soon as possible is the key point for the treatment of LPS. LPS of Sc causing nerve root irritation is rare but curable with early diagnosis and proper therapy. The culture of irrigation fluid obtained from vertebrae by needle puncture may be an effective and sensitive attempt for potential infection of spine to identify the causative organism at early stage of the disease.

Determining the Genetic Characteristics of Resistance and Virulence of the "Epidermidis Cluster Group" Through Pan-Genome Analysis

Staphylococcus caprae, Staphylococcus capitis, and Staphylococcus epidermidis belong to the “Epidermidis Cluster Group” (ECG) and are generally opportunistic pathogens. In this work, whole genome sequencing, molecular cloning and pan-genome analysis were performed to investigate the genetic characteristics of the resistance, virulence and genome structures of 69 ECG strains, including a clinical isolate (S. caprae SY333) obtained in this work. Two resistance genes (blaZ and aadD2) encoded on the plasmids pSY333-41 and pSY333-45 of S. caprae SY333 were confirmed to be functional. The bla region in ECG exhibited three distinct structures, and these chromosome- and plasmid-encoded bla operons seemed to follow two different evolutionary paths. Pan-genome analysis revealed their pan-genomes tend to be “open.” For the virulence-related factors, the genes involved in primary attachment were observed almost exclusively in S. epidermidis, while the genes associated with intercellular aggregation were observed more frequently in S. caprae and S. capitis. The type VII secretion system was present in all strains of S. caprae and some of S. epidermidis but not in S. capitis. Moreover, the isd locus (iron regulated surface determinant) was first found to be encoded on the genomes of S. caprae and S. capitis. These findings suggested that the plasmid and chromosome encoded bla operons of ECG species underwent different evolution paths, as well as they differed in the abundance of virulence genes associated with adherence, invasion, secretion system and immune evasion. Identification of isd loci in S. caprae and S. capitis indicated their ability to acquire heme as nutrient iron during infection.

Skin Microbiome Differences in Atopic Dermatitis and Healthy Controls in Egyptian Children and Adults, and Association with Serum Immunoglobulin E

Atopic dermatitis (AD) is a complex, multifactorial, chronic pruritic inflammatory skin disease. We report the first microbiome study and new insights on the relationship between skin microbiota variation and AD susceptibility in a population sample from Egypt. We characterized the skin microbiome in 75 patients with AD and 20 healthy controls using Illumina MiSeq sequencing of 16S rRNA gene. Overall, bacterial diversity of skin microbiome in patients with AD was less than those of the healthy subjects. Genus level analysis revealed significant abundance variations by age, disease severity, locality, or immune response. Among these genera, Streptococcus, Cutibacterium, and Corynebacterium appeared to be specific signatures for AD in children, adolescents, and adults, respectively, while Staphylococcus was noted as a potential biomarker candidate for AD. Additionally, functional potential of metagenomes shifted the overall metabolic pathways to participate in the exacerbation of disease. Total immunoglobulin E (IgE) levels were positively correlated with relative enrichment of certain Staphylococcus aureus subspecies. Finally, AD-related differences in skin bacterial diversity appeared to be in part linked to the serum IgE level. These new observations attest to the promise of microbiome science and metagenomic analysis in AD specifically, and clinical dermatology broadly.

Puerperal septic shock and necrotizing fasciitis caused by staphylococcus caprae and Escherichia coli

Puerperal sepsis is one of the leading causes of maternal morbidity and mortality worldwide. Postpartum pelvic infections can cause various complications, including wound infections and necrotizing fasciitis. Several microorganisms are known to cause such infections; however, no study has reported on staphylococcus caprae, a coagulase-negative staphylococcus that is isolated frequently from animals and infrequently from human specimens, as a causative agent. Here, we report a rare case of septic shock complicated by necrotizing fasciitis after a cesarean section. This is the first report of a human isolate of S. caprae in association with puerperal sepsis and necrotizing fasciitis.

Complete genome sequencing of three human clinical isolates of Staphylococcus caprae reveals virulence factors similar to those of S. epidermidis and S. capitis

Background

Staphylococcus caprae is an animal-associated bacterium regarded as part of goats’ microflora. Recently, S. caprae has been reported to cause human nosocomial infections such as bacteremia and bone and joint infections. However, the mechanisms responsible for the development of nosocomial infections remain largely unknown. Moreover, the complete genome sequence of S. caprae has not been determined.

Results

We determined the complete genome sequences of three methicillin-resistant S. caprae strains isolated from humans and compared these sequences with the genomes of S. epidermidis and S. capitis, both of which are closely related to S. caprae and are inhabitants of human skin capable of causing opportunistic infections. The genomes showed that S. caprae JMUB145, JMUB590, and JMUB898 strains contained circular chromosomes of 2,618,380, 2,629,173, and 2,598,513 bp, respectively. JMUB145 carried type V SCCmec, while JMUB590 and JMUB898 had type IVa SCCmec. A genome-wide phylogenetic SNP tree constructed using 83 complete genome sequences of 24 Staphylococcus species and 2 S. caprae draft genome sequences confirmed that S. caprae is most closely related to S. epidermidis and S. capitis. Comparative complete genome analysis of eight S. epidermidis, three S. capitis and three S. caprae strains revealed that they shared similar virulence factors represented by biofilm formation genes. These factors include wall teichoic acid synthesis genes, poly-gamma-DL-glutamic acid capsule synthesis genes, and other genes encoding nonproteinaceous adhesins. The 17 proteinases/adhesins and extracellular proteins known to be associated with biofilm formation in S. epidermidis were also conserved in these three species, and their biofilm formation could be detected in vitro. Moreover, two virulence-associated gene clusters, the type VII secretion system and capsular polysaccharide biosynthesis gene clusters, identified in S. aureus were present in S. caprae but not in S. epidermidis and S. capitis genomes.

Conclusion

The complete genome sequences of three methicillin-resistant S. caprae isolates from humans were determined for the first time. Comparative genome analysis revealed that S. caprae is closely related to S. epidermidis and S. capitis at the species level, especially in the ability to form biofilms, which may lead to increased virulence during the development of S. caprae infections.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5185-9) contains supplementary material, which is available to authorized users.

Staphylococcus caprae: A Skin Commensal with Pathogenic Potential

Staphylococcus caprae (S. caprae) is a catalase-positive, coagulase-negative organism that was first isolated from goat milk, and was later found to colonize healthy human skin, nails, and nasal mucosa. Rarely, this commensal organism can become pathogenic in humans. S. caprae has been implicated in a variety of human infections, with the highest incidence being in bone and joint infections. We describe a man who, after receiving facet joint injections for back pain, developed native vertebral discitis, vertebral osteomyelitis with phlegmon, and bilateral psoas abscesses, from which S. caprae was isolated.

Staphylococcus caprae bacteraemia and native bone infection complicated by therapeutic failure and elevated MIC: a case report

Introduction.Staphylococcus caprae is a coagulase-negative staphylococcus that has been reported in several cases as a human pathogen. However, it has rarely been reported as pathogen in native bone. Furthermore, the reported MIC levels noted in the literature for vancomycin were <2 µg ml⁻¹making vancomycin a first line choice for infected patients.

Case presentation. We report a case of Staphylococcus caprae causing osteomyelitis of the lumbar spine and bacteraemia and resulting in sepsis and ultimately the demise of a patient despite appropriate prolonged antibiotic therapy.

Conclusion.Staphylococcus caprae has been reported as a human pathogen since 1983 when it was discovered. We report a case involving native bone infection which is rare in the absence of mechanical hardware. Furthermore, this strain had an elevated MIC for vancomycin which has not been reported in the literature.

Staphylococcus caprae native mitral valve infective endocarditis

Introduction:

Staphylococcus caprae is a rare cause of infective endocarditis. Here, we report a case involving the native mitral valve in the absence of an implantable cardiac electronic device.

Case presentation:

A 76-year-old man presented with a 2 week history of confusion and pyrexia. His past medical history included an open reduction and internal fixation of a humeral fracture 17 years previously, which remained non-united despite further revision 4 years later. There was no history of immunocompromise or farm-animal contact. Two sets of blood culture bottles, more than 12 h apart, were positive for S. caprae. Trans-thoracic echocardiography revealed a 1×1.2 cm vegetation on the mitral valve, with moderate mitral regurgitation. Due to ongoing confusion, he had a magnetic resonance imaging brain scan, which showed a subacute small vessel infarct consistent with a thromboembolic source. A humeral SPECT-CT (single-photon emission computerized tomography-computerized tomography) scan showed no clear evidence of acute osteomyelitis. Surgical vegetectomy and mitral-valve repair were considered to reduce the risk of further systemic embolism and progressive valve infection. However, the potential risks of surgery to this patient led to a decision to pursue a cure with antibiotic therapy alone. He remained well 3 months after discharge, with repeat echocardiography demonstrating a reduction in the size of the vegetation (0.9 cm).

Conclusion:

Management of this infection was challenging due to its rarity and its unclear progression, complicated by the dilemma surrounding surgical intervention in a patient with a complex medical background.

Characterization of Staphylococcus caprae Clinical Isolates Involved in Human Bone and Joint Infections, Compared with Goat Mastitis Isolates

Staphylococcus caprae is an emerging microorganism in human bone and joint infections (BJI). The aim of this study is to describe the features of S. caprae isolates involved in BJI (H for human) compared with those of isolates recovered in goat mastitis (A for animal). Fourteen isolates of each origin were included. Identifications were performed using a Vitek 2 GP ID card, tuf gene sequencing, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) Vitek MS. Molecular typing was carried out using pulsed-field gel electrophoresis (PFGE) and DiversiLab technology. The crystal violet method was used to determine biofilm-forming ability. Virulence factors were searched by PCR. Vitek MS technology provides an accurate identification for the two types of isolates compared to that of gold-standard sequencing (sensitivity, 96.4%), whereas the Vitek 2 GP ID card was more effective for H isolates. Molecular typing methods revealed two distinct lineages corresponding to the origin despite few overlaps: H and A. In our experimental conditions, no significant difference was observed in biofilm production ability between H and A isolates. Nine isolates (5 H isolates and 4 A isolates) behaved as weak producers while one A isolate was a strong producer. Concerning virulence factors, the autolysin atlC and the serine aspartate adhesin (sdrZ) genes were detected in 24 isolates (86%), whereas the lipase gene was always detected, except in one H isolate (96%). The ica operon was present in 23 isolates (82%). Fibrinogen-binding (fbe) or collagen-binding (cna) genes were not detected by using primers designed for Staphylococcus aureus or Staphylococcus epidermidis, even in low stringency conditions. Although S. caprae probably remains underestimated in human infections, further studies are needed to better understand the evolution and the adaptation of this species to its host.

Whole-Genome Sequence of Multidrug-Resistant Staphylococcus caprae Strain 9557, Isolated from Cerebrospinal Fluid

Staphylococcus caprae strain 9557 was isolated from a cerebrospinal fluid sample. The assembled genome contained 2,747,651-bp nucleotides with 33.34% GC content. Consistent with its phenotypic characteristics, the genome harbors a varying repertoire of putative virulence factors involved in invasion, survival, and growth in the host cells.

The cross-contamination potential of mobile telephones

The use of mobile devices for professional, business, educational, personal and social purposes has accelerated exponentially over the last decade. Staff working in healthcare organisations, and patients and visitors using healthcare settings, understandably want to use mobile technology. Concerns have been raised about safety in terms of interference with equipment, and threats to privacy and dignity, yet less policy attention has been paid to infection risks.

Healthcare professional students were supplied with smartphones as part of a larger educational project. Devices collected from a sub-sample of students working in operating theatre contexts were sampled to estimate the cross-contamination potential of the technology. A longitudinal multiple measures design was used. Under laboratory conditions, samples were taken from surfaces using swabbing techniques followed by contact plating. The devices were subsequently cleaned with 70% isopropyl alcohol and returned to the students.

All devices demonstrated microbial contamination and over three quarters (86%) polymicrobial contamination. The technique and sites used to sample for microbial contamination influenced the levels of contamination identified. Swabbing alone was less likely to isolate polymicrobial contamination than contact plating, and some microorganisms were isolated only by contact plates and not by swabbing of the same area.

The findings from this study demonstrate further research is urgently needed to inform evidence-based infection control policy on the use of personal equipment such as mobile devices in the healthcare settings where contamination may have adverse effects on patients, staff and visitors.

Bacterial DNA from orthopedic implants after routine removal

Bacterial 16S rDNA was monitored and identified from orthopedic metallic implants after routine or septic removal from patients in a German hospital. From March to June 2009, 28 metallic implants, 10 human biopsies, and 6 foam dressings from 28 patients were investigated. After analysis of this first collective, the methods were optimized to enhance sensitivity and to reduce interference with human DNA. Then a second collective consisting of 21 metallic implants from 21 patients was investigated from June 2009 to January 2010. In the first collective, 71% of the metallic implants were negative for eubacterial DNA. Pathogens such as Staphylococcus aureus and opportunists such as Lactobacillus rhamnosus were identified in 11% of the samples, whereas the residual 18% positive results were classified as from skin sources or could not be confirmed. Tissue, secretion, and bone samples as well as foam dressings from the same collective also contained pathogens and opportunists. After the optimization of the methods, a considerable increase of positive samples was seen: in the second collective 19 of the 21 metallic implants proved to be positive for eubacterial 16S rDNA. Bacterial DNA from environmental sources was detected in 13 samples, and in 20 specimens, predominantly mostly the skin. Opportunistic pathogens were detected in 19 samples. Interestingly, septic complications did not occur despite the presence of bacterial DNA. The results obtained up to now encourage us not only to continue a directed monitoring of bacterial DNA on orthopedic implants in practice but also to look intensely for possible sources of bacterial contamination during and after insertion or during removal of such implants.

High-throughput molecular identification of Staphylococcus spp. isolated from a clean room facility in an environmental monitoring program

BACKGROUND

The staphylococci are one of the most common environmental isolates found in clean room facility. Consequently, isolation followed by comprehensive and accurate identification is an essential step in any environmental monitoring program.

FINDINGS

We have used the API Staph identification kit (bioMérieux, France) which depends on the expression of metabolic activities and or morphological features to identify the Staphylococcus isolates. The API staphylococci showed low sensitivity in the identification of some species, so we performed molecular methods based on PCR based fingerprinting of glyceraldehyde-3-phosphate dehydrogenase encoding gene as useful taxonomic tool for examining Staphylococcus isolates.

CONCLUSIONS

Our results showed that PCR protocol used in this study which depends on genotypic features was relatively accurate, rapid, sensitive and superior in the identification of at least 7 species of Staphylococcus than API Staph which depends on phenotypic features.

[Not Available]

As a coagulase negative Staphylococcus species, S. caprae is not considered as a clinically-significant member, unlike S. epidermidis. In this report, we describe a case of sepsis resulting from S. caprae infection. This relatively young woman was in generally good health and contracted S. caprae most probably during her treatment of an acute pulmonary embolism. The purpose of this report is to raise awareness of this otherwise innocuous staphylococcal species in clinical settings.

Staphylococcus caprae meningitis following intraspinal device infection

A case is reported of Staphylococcus caprae meningitis due to infection of an intraspinal analgesia pump. The subclinical and pauci-symptomatic clinical course of the infection strongly suggested a chronic device contamination.

Comparative study using various methods for identification of Staphylococcus species in clinical specimens

Coagulase-negative staphylococci (CNS) play a predominant role in nosocomial infections. Rapid, reliable identification of these organisms is essential for accurate diagnosis and prompt effective treatment of these infections. Quite recently, the VITEK 2 g-positive (gram-positive [GP]) identification card (bioMérieux) has been redesigned for greater accuracy in the identification of gram-positive cocci. We compared the BD Phoenix (Becton Dickinson) and VITEK 2 (bioMérieux) automated microbiology systems, using their respective update version cards, and the API ID32 STAPH test. The glyceraldehyde-3-phosphate dehydrogenase (gap) gene-based T-RFLP (terminal restriction fragment length polymorphism) method was used for verifying the results. In total, 86 clinical isolates of CNS and 27 reference strains were analyzed. The results show that for identification of CNS, the automated identification methods using the newest VITEK 2 and BD Phoenix identification cards are comparable. However, API ID32 STAPH revealed more correct results compared to both automated microbiology systems. Despite the increased performance of the phenotypic automated identification systems compared to the former versions, molecular methods, e.g., the gap-based T-RFLP method, still show superior accuracy in identifying Staphylococcus species other than Staphylococcus aureus.

Use of genotypic identification by sodA sequencing in a prospective study to examine the distribution of coagulase-negative Staphylococcus species among strains recovered during septic orthopedic surgery and evaluate their significance

A total of 212 coagulase-negative Staphylococcus strains recovered prospectively during 119 surgeries for proven or suspected bone and joint infection (BJI) were identified by sodA sequencing. These strains were identified as 151 Staphylococcus epidermidis isolates, 15 S. warneri isolates, 14 S. capitis isolates, 9 S. hominis isolates, 6 S. lugdunensis isolates, 5 S. haemolyticus isolates, 4 S. caprae isolates, 4 S. pasteuri isolates, 3 S. simulans isolates, and 1 S. cohnii isolate. Only S. epidermidis, S. lugdunensis, S. capitis, and S. caprae were found to be infecting organisms and were involved, respectively, in 35 (81.4%), 3 (7.0%), 3 (7.0%), and 2 (4.6%) cases of BJI.

Methicillin-resistant Staphylococcus caprae in a neonatal intensive care unit

Staphylococcus caprae, a hemolytic coagulase-negative staphylococcus that is infrequently associated with humans, was initially detected in specimens from six infants in our neonatal intensive care unit due to phenotypic characteristics common to methicillin-resistant Staphylococcus aureus. These isolates were subsequently identified as S. caprae by the Automated RiboPrinter microbial characterization system. This prompted an 8-month retrospective investigation in our neonatal intensive care unit. S. caprae was the cause of 6 of 18 episodes of coagulase-negative staphylococcal bacteremia, was the most common coagulase-negative staphylococcus recovered from the nares of 6 of 32 infants surveyed in a methicillin-resistant S. aureus surveillance program, and was isolated from 1 of 37 health care providers' hands. Of 13 neonatal intensive care unit isolates tested, all were methicillin resistant and positive for the mecA gene. All 21 isolates were found to be a single strain by Automated RiboPrinter and pulsed-field gel electrophoresis with ApaI or SmaI digestion; ApaI was more discriminating in analyzing epidemiologically unrelated strains than Automated RiboPrinter or electrophoresis with SmaI. These findings extend the importance of S. caprae, emphasize its similarities to methicillin-resistant S. aureus, and demonstrate its ability to persist in an intensive care unit setting.

Staphylococcus caprae strains carry determinants known to be involved in pathogenicity: a gene encoding an autolysin-binding fibronectin and the ica operon involved in biofilm formation

The atlC gene (1,485 bp), encoding an autolysin which binds fibronectin, and the ica operon, involved in biofilm formation, were isolated from the chromosome of an infectious isolate of Staphylococcus caprae and sequenced. AtlC (155 kDa) is similar to the staphylococcal autolysins Atl, AtlE, Aas (48 to 72% amino acid identity) and contains a putative signal peptide of 29 amino acids and two enzymatic centers (N-acetylmuramoyl-L-alanine amidase and endo-beta-N-acetylglucosaminidase) interconnected by three imperfect fibronectin-binding repeats. The glycine-tryptophan (GW) motif found in the central and end part of each repeat may serve for cell surface anchoring of AtlC as they do in Listeria monocytogenes. The S. caprae ica operon contains four genes closely related to S. epidermidis and S. aureus icaA, icaB, icaC, and icaD genes (> or = 68% similarity) and is preceded by a gene similar to icaR (> or =70% similarity). The polypeptides deduced from the S. caprae ica genes exhibit 67 to 88% amino acid identity to those of S. epidermidis and S. aureus ica genes. The ica operon and icaR gene were analyzed in 14 S. caprae strains from human specimens or goats' milk. Some of the strains produced biofilm, and others did not. All strains carry the ica operon and icaR of the same sizes and in the same relative positions, suggesting that the absence of biofilm formation is not related to the insertion of a mobile element such as an insertion sequence or a transposon.

Distribution of Staphylococcus sciuri subspecies among human clinical specimens, and profile of antibiotic resistance

The distribution of three subspecies comprising Staphylococcus sciuri was determined for a collection of 30 clinical isolates originating from Morocco, the United Kingdom, and France. The sources of these isolates were principally wounds, skin, and soft tissue infections. At the species level, the isolates were identified according to biochemical characteristics and at the subspecies level by the ribotyping technique. PCR analysis performed with the 16S-23S ribosomal DNA intergenic spacer was less powerful for subspecies differentiation. S. sciuri subsp. sciuri was the most frequent subspecies (21 isolates) found in the collection, whereas S. sciuri subsp. rodentium (seven isolates) and S. sciuri subsp. carnaticus (two isolates) were less common. mecA or a mecA-related gene was detected by PCR and Southern blot in all 30 S. sciuri isolates, supporting the suggestion that S. sciuri species are the natural reservoir of the mecA gene. While the linA/linA' gene coding for lincomycin resistance was present in five isolates, an uncharacterized gene for this resistance was suspected in seventeen other isolates.

Detection of Staphylococcus aureus and Staphylococcus epidermidis in clinical samples by 16S rRNA-directed in situ hybridization

Staphylococcus epidermidis and Staphylococcus aureus are the most common causes of medical device-associated infections, including septicemic loosenings of orthopedic implants. Frequently, the microbiological diagnosis of these infections remains ambiguous, since at least some staphylococci have the capacity to reduce their growth rate considerably. These strains exhibit a small-colony phenotype, and often they are not detectable by conventional microbiological techniques. Moreover, clinical isolates of S. aureus and S. epidermidis adhere to polymer and metal surfaces by the generation of thick, multilayered biofilms consisting of bacteria and extracellular polysaccharides. This study reports improved detection and identification of S. aureus and S. epidermidis by an in situ hybridization method with fluorescence-labeled oligonucleotide probes specific for staphylococcal 16S rRNA. The technique has proven to be suitable for the in situ detection of staphylococci, which is illustrated by the identification of S. epidermidis in a connective tissue sample obtained from a patient with septicemic loosening of a hip arthroplasty. We also show that this technique allows the detection of intracellularly persisting bacteria, including small-colony variants of S. aureus, and the differentiation of S. epidermidis from other clinically relevant staphylococci even when they are embedded in biofilms. These results suggest that the 16S rRNA in situ hybridization technique could represent a powerful diagnostic tool for the detection and differentiation of many other fastidious microorganisms.