Antibiotic Management and Antibiotic Resistance in Hand Infections

The rates of methicillin-resistant infections in the hand and upper extremity approach 50% in many facilities. In addition, multidrug resistance is beginning to include clindamycin. This article discusses the history, prevalence, and treatment of both community-acquired and health care-associated methicillin-resistant Staphylococcus aureus in regard to hand infections.

Observational study of skin and soft-tissue Staphylococcus aureus infection in patients infected with HIV-1 and epidemics of Panton-Valentine leucocidin-positive community-acquired MRSA infection in Osaka, Japan

BACKGROUND

In patients infected with human immunodeficiency virus (HIV)-1 at our hospital, we observed increases in skin and soft-tissue infections (SSTIs) by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Therefore, we analyzed factors related to CA-MRSA infection and performed a molecular epidemiological investigation.

METHODS

HIV-1-infected patients were diagnosed with SSTIs related to S. aureus between 2007 and 2017, and MRSA was classified into community and hospital-acquired types according to published criteria. Information was collected retrospectively from clinical records, and multivariate analysis by logistic regression was performed concerning factors related to CA-MRSA infection. We evaluated the staphylococcal cassette chromosome mec (SCCmec) type, multilocus sequence type, and the presence of genes encoding Panton-Valentine leucocidin (PVL) in 27 MRSA samples isolated during and after 2015.

RESULTS

We found 218 episodes of SSTIs in 169 patients, and among initial episodes of SSTIs, the MRSA ratio was higher from 2015 to 2017 relative to that from 2007 to 2014 (88% vs. 44%; p < 0.0001). Multivariate analysis showed that in men having sex with men [MSM; odds ratio (OR): 13] and exhibiting onset during and after 2015 (OR: 5.4), CD4⁺ cell count ≥200 cells/μL (OR: 5.6) and the presence of lesions in the lower abdomen or buttocks (OR: 9.5) were independent factors related to CA-MRSA infection. Additionally, PVL+/ST8/SCCmec type IV MRSA was the predominant pathogen (22 cases; 81%).

CONCLUSIONS

These data describe an increased prevalence of SSTIs due to PVL-positive ST8-MRSA-IV, not previously considered epidemic in Japan, in MSM infected with HIV-1 in Osaka, Japan.

A risk as an infection route: Nasal colonization of methicillin-resistant Staphylococcus aureus USA300 clone among contact sport athletes in Japan

Panton-Valentine leukocidin (PVL)-positive USA300 clone is a highly pathogenic and global epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clone. Athletes are particularly vulnerable to CA-MRSA infection because of the frequency of skin trauma, close-contact situations, and sharing of equipment that is customary in the athletic setting. We experienced a case of Japanese collegiate football player with septic pulmonary emboli secondary to infectious iliofemoral deep venous thrombosis caused by the USA300 clone. Here, we screened the nasal carriage of USA300 clone colonization among asymptomatic teammate of the patient to elucidate the infection route. Among 69 nasal samples, CA-MRSA strains were found in 5.8% (four samples). Molecular epidemiological analyses showed that three of the CA-MRSA strains were USA300 clone. Furthermore, pulsed-field gel electrophoresis revealed that all nasal USA300 clones showed 100% identity with the USA300 clone isolated from their teammate with critical infection. Our findings indicate that nasal colonization of the PVL-positive CA-MRSA, especially USA300 clone, pose a threat among contact sport athletes in Japan likewise other countries. An immediate infection control strategy for contact sport athletes is necessary to prevent outbreaks of PVL-positive CA-MRSA infections.

An outbreak of severe infectious diseases caused by methicillin-resistant Staphylococcus aureus USA300 clone among hospitalized patients and nursing staff in a tertiary care university hospital

The USA300 clone, which produces Panton-Valentine leukocidin (PVL), is a major highly pathogenic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clone that is spreading throughout the world. Although the prevalence of the USA300 clone in Japan was very limited a decade ago, its incidence has been increasing in both community and hospital settings in recent years. There is great concern that the USA300 clone will cause more complicated diseases and become a serious threat to immunocompromised patients in hospital settings. Here, we report an outbreak of severe infectious diseases in a tertiary care university hospital involving the incidence of deep infections, including bacteremia, and continuous and frequent isolation of MRSA strains for five months from six patients and a healthy nursing staff member in the same ward. The genotype of all MRSA isolates was identical to that of the USA300 clone. Furthermore, pulsed-field gel electrophoresis analysis indicated that all MRSA had the same patterns. These data demonstrate that a USA300 clone outbreak had occurred in the hospital. Fortunately, this outbreak was terminated subsequent to the interventions of the infection control team and all patients recovered following the appropriate therapies. Our report demonstrates that patients carrying highly pathogenic CA-MRSA have the potential to become a source of nosocomial outbreaks that can spread to healthy healthcare workers. Therefore, stricter standard precautions should be applied for all patients at the time of admission to prevent such nosocomial outbreaks.

Clonal clusters and virulence factors of methicillin-resistant Staphylococcus Aureus: Evidence for community-acquired methicillin-resistant Staphylococcus Aureus infiltration into hospital settings in Chennai, South India

Background and Objective

Staphylococcus aureus is one of the major pathogens of nosocomial infections as wells as community-acquired (CA) infections worldwide. So far, large-scale comprehensive molecular and epidemiological characterisation of S. aureus from very diverse settings has not been carried out in India. The objective of this study is to evaluate the molecular, epidemiological and virulence characteristics of S. aureus in both community and hospital settings in Chennai, southern India.

Methods

S. aureus isolates were obtained from four different groups (a) healthy individuals from closed community settings, (b) inpatients from hospitals, (c) outpatients from hospitals, representing isolates of hospital-community interface and (d) HIV-infected patients to define isolates associated with the immunocompromised. Antibiotic susceptibility testing, multiplex polymerase chain reactions for detection of virulence and resistance determinants, molecular typing including Staphylococcal cassette chromosome mec (SCCmec) and agr typing, were carried out. Sequencing-based typing was done using spa and multilocus sequence typing (MLST) methods. Clonal complexes (CC) of hospital and CA methicillin-resistant S. aureus (MRSA) were identified and compared for virulence and resistance.

Results and Conclusion

A total of 769 isolates of S. aureus isolates were studied. The prevalence of MRSA was found to be 7.17%, 81.67%, 58.33% and 22.85% for groups a, b, c and d, respectively. Of the four SCCmec types (I, III, IV and V) detected, SCCmec V was found to be predominant. Panton-Valentine leucocidin toxin genes were detected among MRSA isolates harbouring SCCmec IV and V. A total of 78 spa types were detected, t657 being the most prevalent. 13 MLST types belonging to 9 CC were detected. CC1 (ST-772, ST-1) and CC8 (ST238, ST368 and ST1208) were found to be predominant among MRSA. CA-MRSA isolates with SCCmec IV and V were isolated from all study groups including hospitalised patients and were found to be similar by molecular tools. This shows that CA MRSA has probably infiltrated into the hospital settings.

Comparative analysis of methicillin-resistant Staphylococcus aureus isolated from outpatients of dermatology unit in hospitals and clinics

Community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) is a causative agent of intractable skin infections. In general, clinical symptoms of hospital outpatients with skin infections are severer than those of clinic patients. Hence, molecular epidemiological features of the CO-MRSA strains from hospital outpatients are predicted to be different from those of clinic patients. Here, we conducted a comparative analysis for CO-MRSA isolates from outpatients with impetigo in hospitals and clinics located in the same district of Tokyo, Japan. Incidence of MRSA infection was higher in hospital outpatients (21.5%, 20/93 isolates) than in clinic patients (14.5%, 121/845 isolates). The resistance rate to clindamycin, which is a common topical antimicrobial agent in dermatology, in the isolates from hospital outpatients (60.0%) was higher than those from clinic patients (31.4%). Proportion of the staphylococcal cassette chromosome (SCC) mec type II, which is a representative type of hospital-acquired MRSA in Japan, in the isolates from hospital outpatients (65.0%) was significantly higher than those from clinic patients (30.6%) (P < 0.01). Multilocus sequence typing showed that the clonal complex 89-SCCmec type II (CC89-II) clone, which exhibits clindamycin resistance, was the most predominant (55.0%) in the isolates from hospital outpatients. On the other hand, all CC8-IV, CC121-V, and CC89-V clones accounted for 60% in clinic patients were susceptible to clindamycin. Our findings suggested that the clindamycin-resistant CC89-II CO-MRSA clone might be more related to skin infections in hospital outpatients than clinic patients.

A case of acute septic arthritis of the hip joint caused by Panton-Valentine leukocidin-positive ST772 community-acquired methicillin-resistant Staphylococcus aureus

Acute septic arthritis (ASA) caused by Staphylococcus aureus can lead to fulminant arthritis and cause permanent joint destruction. In particular, infection caused by methicillin-resistant Staphylococcus aureus (MRSA) becomes intractable and severe owing to limitation of therapeutic drugs. Here, we report the case of a young patient with ASA without any record of overseas travel, who was infected by the Panton-Valentine leukocidin-positive Bengal-Bay clone, which is a predominant community-acquired MRSA in India.

Dissemination of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus USA300 clone in multiple hospitals in Tokyo, Japan

OBJECTIVES

Panton-Valentine leukocidin (PVL) gene (lukS/F-PV)-positive community-acquired methicillin-resistant Staphylococcus aureus (MRSA), particularly the USA300 clone, is a health concern worldwide. Recently, community-acquired MRSA clones have been found to spread and persist in hospital settings. We aimed to investigate the prevalence and molecular epidemiologic features of lukS/F-PV-positive MRSA in Japanese hospitals.

METHODS

A total of 3433 MRSA isolated from nine hospitals in 2011-2015 were assessed. Molecular epidemiologic analysis performed by staphylococcal cassette chromosome mec typing, PVL typing, arginine catabolic mobile element typing, detection of virulence determinants, multilocus sequence typing, pulsed-field gel electrophoresis and antimicrobial susceptibility testing.

RESULTS

The detection rate of lukS/F-PV was increased annually from 0.6% (5/817) in 2011 to 3.1% (17/544) in 2015. Molecular epidemiologic analysis for 64 lukS/F-PV-positive MRSA isolates revealed that 42 isolates (65.6%) were the USA300 clone. Resistance rates of levofloxacin and gentamicin among lukS/F-PV-positive isolates increased annually as a result of increased prevalence of the multidrug-resistant USA300 clone.

CONCLUSIONS

This is the first report on dissemination of the USA300 clone and PVL-positive MRSA in multiple Japanese hospitals. Our data strongly suggest that the USA300 clone may become epidemic in Japanese hospitals.

Community-acquired methicillin-resistant Staphylococcus aureus carriage rate and antimicrobial susceptibility in a tertiary center, Iran

Background:

This study was aimed to determine frequency and antimicrobial susceptibility of Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) among colonized patients in outpatient status.

Materials and Methods:

A total of 2000 nasal nares specimens were collected and inoculated on mannitol salt agar. MRSAs were identified based on mannitol positivity and coagulase test followed by cefoxitin disc diffusion test. Antimicrobial susceptibility of MRSA isolates was performed by E-test method for vancomycin and doxycycline as well as disc diffusion method for sulfamethoxazole-trimethoprim (SMX-TMP), erythromycin, linezolid, and clindamycin. D-test was performed for detection of inducible resistance to clindamycin.

Results:

Overall, nasal carrier rate of S. aureus and CA-MRSA was estimated 22% and 1.25%, respectively. Out of the 440 S. aureus isolates, 25 isolates were MRSA. All were susceptible to vancomycin and linezolid, and susceptibility rates to SMX-TMP, erythromycin, levofloxacin, doxycycline, and clindamycin were 68%, 44%, 48%, 40% and 44%, respectively; furthermore, 28.5% of resistant isolates to erythromycin had inducible resistance to clindamycin.

Conclusion:

It seems susceptibility to clindamycin and SMX-TMP, recommended agents for empirical treatment of suspected CA-MRSA, are not promising. Vancomycin and linezolid are effective and reliable antibiotics for the treatment of S. aureus infections.

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

Antimicrobial susceptibility and molecular characteristics of methicillin-resistant Staphylococcus aureus in a Japanese secondary care facility

Methicillin-resistant Staphylococcus aureus (MRSA) is prevalent in Japan, and the Staphylococcus cassette chromosome mec (SCCmec) type II is common among hospital-acquired MRSA isolates. Information pertaining to MRSA characteristics is limited, including SCCmec types, in primary or secondary care facilities. A total of 128 MRSA isolates (90 skin and soft tissue isolates and 38 blood isolates) were collected at a secondary care facility, Kawatana Medical Center, from 2005 to 2011. Antimicrobial susceptibility testing for anti-MRSA antibiotics and molecular testing for SCCmec and virulence genes (tst, sec, etb, lukS/F-PV) were performed. Strains positive for lukS/F-PV were analyzed by multilocus sequence typing and phage open-reading frame typing. SCCmec typing in skin and soft tissue isolates revealed that 65.6% had type IV, 22.2% had type II, 8.9% had type I, and 3.3% had type III. In blood isolates, 50.0% had type IV, 47.4% had type II, and 2.6% had type III. Minimum inhibitory concentrations, MIC(50)/MIC(90), against vancomycin, teicoplanin, linezolid, and arbekacin increased slightly in SCCmec II isolates from skin and soft tissue. MICs against daptomycin were similar between sites of isolation. SCCmec type II isolates possess tst and sec genes at a greater frequently than SCCmec type IV isolates. Four lukS/F-PV-positive isolates were divided into two clonal patterns and USA300 was not included. In conclusion, SCCmec type IV was dominant in blood, skin, and soft tissue isolates in a secondary care facility in Japan. Because antimicrobial susceptibility varies with the SCCmec type, SCCmec typing of clinical isolates should be monitored in primary or secondary care facilities.

Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus producing Panton-Valentine leukocidin in a Chinese teenager: case report and literature review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) has now been established as an important community-acquired pathogen. Although necrotizing pneumonia caused by community-acquired MRSA (CA-MRSA) strains producing Panton-Valentine leukocidin (PVL) has been reported with increasing frequency in many countries, it has been reported in only a few children younger than 1 year of age in Mainland China.

METHODS

We describe a case of life-threatening necrotizing pneumonia due to PVL-positive CA-MRSA in a 15-year-old previously healthy female who presented with high fever, shivering, a dry cough, and dyspnea. Details of the clinical outcomes, microbiological data, and therapies for this patient were collected and compared with those of cases reported in the literature on CA-MRSA.

RESULTS

Computed tomography (CT) findings showed cavitary consolidations in both lungs and bilateral pleural effusion. MRSA strains isolated from the patient's sputum and pleural fluid were susceptible to most non-β-lactam antimicrobial agents except for clindamycin and erythromycin. Both of these isolates tested positive for the mecA gene as well as PVL genes, and were identified as ST59-MRSA-SCCmec type IV-spa type t437. The patient was treated successfully with linezolid, fosfomycin, and teicoplanin.

CONCLUSIONS

To our knowledge, this is the first report from Mainland China of necrotizing pneumonia due to PVL-positive CA-MRSA among those aged older than 1 year. CA-MRSA necrotizing pneumonia should be considered in the differential diagnosis of severe community-acquired pneumonia, particularly in previously healthy individuals.

Characterization of methicillin-resistant Staphylococcus aureus isolated from tertiary care hospitals in Tokyo, Japan

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) remains problematic in both hospital and community settings. Investigations of MRSA existing in the local area are necessary to understand the detailed epidemiology of healthcare-associated MRSA (HA-MRSA). In the present study, molecular epidemiological analysis was performed on 584 MRSA isolated from four hospitals in Tokyo, Japan. In the pulsed-field gel electrophoresis (PFGE) analysis, four epidemic pulsotypes (I to IV) were found. The isolates of the epidemic pulsotype I mainly consisted of the SCCmec type II, toxic shock syndrome toxin 1 gene (tst)-negative, spa type t002, and ST764 clones. The ST764 clone, which is a novel hybrid variant of the ST5 HA-MRSA lineage with the arginine catabolic mobile element (ACME), was first found in Niigata, Japan. However, no ACME genes were detected in the isolates of the epidemic pulsotype I. In contrast, the other isolates of the epidemic pulsotypes mainly consisted of the SCCmec type II, tst-positive, spa type t002, and ST5 clones, which are the most predominant clones of HA-MRSA in Japan. Resistance rates of non-β-lactams for the isolates of the epidemic pulsotype I were higher than those of the other epidemic pulsotypes. Our data showed that the novel ACME-negative ST764 clones are being distributed throughout multiple hospitals in Tokyo. The ST764 clones in Tokyo have the potential to acquire ACME in the future, because the ACME-positive ST764 clones have already been found in both hospital and community settings in other areas of Japan.