A defined commensal consortium elicits CD8 T cells and anti-cancer immunity.

There is a growing appreciation for the importance of the gut microbiota as a therapeutic target in various diseases. However, there are only a handful of known commensal strains that can potentially be used to manipulate host physiological functions. Here we isolate a consortium of 11 bacterial strains from healthy human donor faeces that is capable of robustly inducing interferon-γ-producing CD8 T cells in the intestine. These 11 strains act together to mediate the induction without causing inflammation in a manner that is dependent on CD103+ dendritic cells and major histocompatibility (MHC) class Ia molecules. Colonization of mice with the 11-strain mixture enhances both host resistance against Listeria monocytogenes infection and the therapeutic efficacy of immune checkpoint inhibitors in syngeneic tumour models. The 11 strains primarily represent rare, low-abundance components of the human microbiome, and thus have great potential as broadly effective biotherapeutics.

Disseminated Mycobacterium massiliense infection in a patient with myelodysplastic syndrome undergoing allogeneic bone marrow transplantation.

Nontuberculous mycobacteria are ubiquitous in water and soil, and the subset of rapidly growing mycobacteria species can cause severe infections in immunocompromised patients. Solid organ or hematopoietic stem cell transplantation (HSCT) recipients are known to be susceptible to infection by nontuberculous mycobacteria. The nontuberculous mycobacteria species Mycobacterium massiliense (M massiliense) has been classified as a rapidly growing mycobacteria and recognized as a pathogen causing lung and soft tissue infections in humans. However, there have been only a few reported cases of M massiliense infection after solid organ transplantation and HSCT. We herein report another case of M massiliense infection after allogeneic HSCT, which manifested as soft tissue infection, lung infection, and bacteremia.

[Bacteriocidal effects of introducing copper products on highly touched areas in hematology ward].

Nosocomial infection via the hospital environment is a serious problem, and highly touched surfaces are the main route of transmission. Copper has been reported to possess bacteriocidal effects, and the introduction of copper-impregnated products is receiving attention as a potential component of hospital infection control. In this study, copper-impregnated door handles as highly touched areas were introduced in a hematology ward, and their bacteriocidal effects were evaluated in comparison with conventional products. All 12 samples obtained from conventional door handles were positive for bacterial cultures, whereas only 5 of 18 samples from copper-impregnated handles were positive (P<0.0001). The mean number of bacterial colonies per milliliter of sample was 300 (range: 40-1.1×106) in samples from conventional handles, but it was significantly lower in samples from copper-impregnated handles (0; range: 0-220, P<0.0001). While various types of bacteria grew on conventional handles, most of the bacteria on copper-impregnated handles were Bacillus subtilis. These results suggest that the introduction of copper-impregnated products would be useful for hospital infection control by reducing the bacterial burden on highly touched areas. However, the efficacy of this approach against spore-forming bacteria should be further investigated.

Sinusitis caused by Exserohilum rostratum after cord blood transplantation for myelodysplastic syndrome: A case report and literature review.

Invasive fungal disease is a serious infectious complication of allogeneic hematopoietic stem cell transplantation (HSCT). Exserohilum rostratum is a species causing phaeohyphomycosis, which rarely causes invasive disease in humans. We treated a case of sinusitis caused by E. rostratum after cord blood transplantation (CBT). A 60-year-old man with myelodysplastic syndrome, who had a medical history of an operation to correct deviation of the nasal septum, developed sinusitis caused by E. rostratum under prolonged profound neutropenia after a second CBT because of the graft rejection of the first transplantation. Liposomal amphotericin B improved the sinusitis. A literature review revealed nine reported cases of sinusitis caused by E. rostratum, including our case. Although five cases had severe neutropenia at onset (HSCT recipients, n = 2; aplastic anemia, n = 3), the remaining four had no preexisting immunosuppressive conditions. However, three of the four patients had preexisting nasal diseases with or without a history of surgery, as in our case. Excluding our case, the outcome was fatal in five neutropenic patients, whereas the four patients without neutropenia recovered. Although sinusitis caused by E. rostratum is rare, E. rostratum should be recognized as a possible pathogen causing sinusitis in highly immunosuppressed patients such as HSCT recipients. Preexisting nasal disease and/or nasal surgery could be risks for this infection.

Bacteremia due to Capnocytophaga species during chemotherapy-induced neutropenia in patients with hematological malignancies.

The number of reported cases of infections due to Capnocytophaga species (spp.) is limited. We herein describe four cases developing bacteremia due to Capnocytophaga spp. during neutropenia after chemotherapy for hematological malignancies. At the onset of bacteremia, 3 of the 4 patients had oral mucositis, and 2 were co-infected with other bacteria. Two patients developed bacteremia while receiving fluoroquinolone as prophylaxis against bacterial infection. Bacteremia resolved with administration of antimicrobial agents in all patients and no recurrences were observed thereafter. The emergence of fluoroquinolone-resistant or beta-lactamase-producing Capnocytophaga spp. has recently been reported. Therefore, Capnocytophaga spp. could be causative pathogens in breakthrough and refractory infections under fluoroquinolone prophylaxis and empiric therapy, respectively, for febrile neutropenia. Capnocytophaga spp. should be recognized as one of the causative pathogens of febrile neutropenia. Furthermore, accumulation of cases and susceptibility data are required to establish an optimal treatment protocol.

Catheter-related blood stream infection caused by Dermacoccus barathri, representing the first case of Dermacoccus infection in humans.

A 7-year-old boy undergoing home parenteral nutrition with totally implantable central venous access device for chronic intestinal pseudo-obstruction experienced repeated episodes of fever with a temperature above 39.0 °C despite the antibiotic treatment. The fever was considered to be catheter-related blood stream infections, as no other etiology could be justified. Repeated blood culture tests revealed negative after 1-week incubation, whereas some samples of blood collected from the central venous catheter yielded positive and gram-positive rods were detected. These bacteria were detected repeatedly, then the central venous access device was removed with consideration for the possibility of this bacteria being a pathogen. Thereafter, the fever did not recur and the blood culture tests were negative. The causative agent was identified as Dermacoccus barathri based on the 16S rRNA gene sequence and phylogenetic analysis of 6118-bp concatenated sequences of 4 housekeeping genes. Genus Dermacoccus are one form of Actinomycetes isolated from human skin and water, but human infection with Dermacoccus spp. has not been previously reported and the pathogenicity of the bacteria remains unclear. To our knowledge, this is the first reported case of Dermacoccus infection in humans.

High rate of inducible clindamycin resistance in Staphylococcus aureus isolates--a multicenter study in Tokyo, Japan.

The resistance of Staphylococcus aureus (S. aureus) to antibiotics is an increasing problem. Clindamycin has been used as empiric therapy for the rising incidence of community-acquired methicillin-resistant S. aureus (MRSA). As such, the local rate of inducible resistance against clindamycin is an important consideration. This multicenter study was conducted to identify the incidence of inducible clindamycin resistance of S. aureus isolates in Tokyo, the most populous city in Japan. A total of 2408 adult and pediatric samples were collected from a university hospital and two pediatric hospitals between January 2011 and December 2011. Among the 2341 samples analyzed, the incidence of inducible clindamycin resistance in erythromycin-resistant and clindamycin-susceptible/intermediate isolates was found to be 91% (n = 585), a figure much higher compared to most reports from other countries. In conclusion, we found a very high rate of inducible clindamycin resistance in macrolide-resistant S. aureus isolates in our geographic area.

[Bacteremia due to Rothia mucilaginosa after chemotherapy for myeloid malignancies].

The number of reported cases of bacteremia due to Rothia mucilaginosa (R. mucilaginosa), a component of the normal flora of human gastrointestinal tract mucosa, is limited. We encountered three cases of bacteremia due to R. mucilaginosa during neutropenia after chemotherapy for myeloid malignancies. Although all three patients were successfully treated with antimicrobial agents, one patient developed disseminated lesions in the lungs and soft tissue. The portal of R. mucilaginosa bacteremia is reportedly mucositis or dental disorders; however, no such complications were identified in our patients. Even in the absence of a preexisting portal, R. mucilaginosa should be recognized as a potential causative pathogen of bacteremia during neutropenic periods. Accumulations of cases and isolates are required to further elucidate the risk factors for developing R. mucilaginosa bacteremia, its clinical course, and the optimal antimicrobial treatment.

Rationally-defined microbial consortia suppress multidrug-resistant proinflammatory Enterobacteriaceae via ecological control.

Persistent colonization and outgrowth of pathogenic organisms in the intestine may occur due to long-term antibiotic usage or inflammatory conditions, which perpetuate dysregulated immunity and tissue damage1,2. Gram-negative Enterobacteriaceae gut pathobionts are particularly recalcitrant to conventional antibiotic treatment3,4, though an emerging body of evidence suggests that manipulation of the commensal microbiota may be a practical alternative therapeutic strategy5-7. In this study, we rationally isolated and down-selected commensal bacterial consortia from healthy human stool samples capable of strongly and specifically suppressing intestinal Enterobacteriaceae. One of the elaborated consortia, consisting of 18 commensal strains, effectively controlled ecological niches by regulating gluconate availability, thereby reestablishing colonization resistance and alleviating antibiotic-resistant Klebsiella-driven intestinal inflammation in mice. Harnessing these microbial activities in the form of live bacterial therapeutics may represent a promising solution to combat the growing threat of proinflammatory, antimicrobial-resistant bacterial infection.

Safety and efficacy of linezolid in 16 infants and children in Japan.

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It has been licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients. At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolid owing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severe underlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid. Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, or intravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median duration of administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could be evaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showed elevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring that administration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. The other patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for children in Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics for infections with multidrug-resistant Gram-positive bacteria.

[Recurrent cellulitis due to Helicobacter cinaedi after chemotherapy for malignant lymphoma].

A 62-year-old man with diffuse large B-cell lymphoma received five courses of R-CHOP chemotherapy. The patient developed cellulitis in the bilateral lower extremities without fever, and blood culture yielded Helicobacter cinaedi after five-day culture. Although the response to tazobactam/piperacillin (TAZ/PIPC) was prompt, cellulitis recurred immediately after discontinuation of the drug. Even after two months of treatment with PIPC plus amikacin followed by amoxicillin, it recurred again soon after stopping the antibiotics. H. cinaedi reportedly causes bacteremia and cellulitis in immunocompromised patients mostly in patients with acquired immunodeficiency syndrome. Only sporadic cases have been reported in association with hematological malignancies. Physicians should be aware of H. cinaedi as one of the causative pathogens of bacteremia and cellulitis in patients with hematological malignancies. Longer incubation period of blood culture is needed to detect the microbe and long-term use of antimicrobials is required to prevent recurrent cellulitis.

Molecular Analysis of blaKPC-2-Harboring Plasmids: Tn4401a Interplasmid Transposition and Tn4401a-Carrying ColRNAI Plasmid Mobilization from Klebsiella pneumoniae to Citrobacter europaeus and Morganella morganii in a Single Patient.

The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales is a public health concern. KPC-encoding blaKPC is predominantly spread by strains of a particular phylogenetic lineage, clonal group 258, but can also be spread by horizontal transfer of blaKPC-carrying plasmids. Here, we report the transfer of a blaKPC-2-harboring plasmid via mobilization from K. pneumoniae to Citrobacter freundii complex and Morganella morganii strains in a single patient. We performed draft whole-genome sequencing to analyze 20 carbapenemase-producing Enterobacterales strains (15 of K. pneumoniae, two of C. freundii complex, and three of M. morganii) and all K. pneumoniae strains using MiSeq and/or MinION isolated from a patient who was hospitalized in New York and Montreal before returning to Japan. All strains harbored blaKPC-2-containing Tn4401a. The 15 K. pneumoniae strains each belonged to sequence type 258 and harbored a Tn4401a-carrying multireplicon-type plasmid, IncN and IncR (IncN+R). Three of these K. pneumoniae strains also possessed a Tn4401a-carrying ColRNAI plasmid, suggesting that Tn4401a underwent interplasmid transposition. Of these three ColRNAI plasmids, two and one were identical to plasmids harbored by two Citrobacter europaeus and three M. morganii strains, respectively. The Tn4401a-carrying ColRNAI plasmids were each 23,753 bp long and incapable of conjugal transfer via their own genes alone, but they mobilized during the conjugal transfer of Tn4401a-carrying IncN+R plasmids in K. pneumoniae. Interplasmid transposition of Tn4401a from an IncN+R plasmid to a ColRNAI plasmid in K. pneumoniae and mobilization of Tn4401a-carrying ColRNAI plasmids contributed to the acquisition of blaKPC-2 in C. europaeus and M. morganii. IMPORTANCE Plasmid transfer plays an important role in the interspecies spread of carbapenemase genes, including the Klebsiella pneumoniae carbapenemase (KPC)-coding gene, blaKPC. We conducted whole-genome sequencing (WGS) analysis and transmission experiments to analyze blaKPC-2-carrying mobile genetic elements (MGEs) between the blaKPC-2-harboring K. pneumoniae, Citrobacter europaeus, and Morganella morganii strains isolated from a single patient. blaKPC-2 was contained within an MGE, Tn4401a. WGS of blaKPC-2-carrying K. pneumoniae, C. europaeus, and M. morganii strains isolated from one patient revealed that Tn4401a-carrying ColRNAI plasmids were generated by plasmid-to-plasmid transfer of Tn4401a from a multireplicon-type IncN and IncR (IncN+R) plasmid in K. pneumoniae strains. Tn4401a-carrying ColRNAI plasmids were incapable of conjugal transfer in C. europaeus and M. morganii but mobilized from K. pneumoniae to a recipient Escherichia coli strain during the conjugal transfer of Tn4401a-carrying IncN+R plasmid. Therefore, Tn4401a-carrying ColRNAI plasmids contributed to the acquisition of blaKPC-2 in C. europaeus and M. morganii.

TH1 cell-inducing Escherichia coli strain identified from the small intestinal mucosa of patients with Crohn's disease.

Dysbiotic microbiota contributes to the pathogenesis of Crohn's disease (CD) by regulating the immune system. Although pro-inflammatory microbes are probably enriched in the small intestinal (SI) mucosa, most studies have focused on fecal microbiota. This study aimed to examine jejunal and ileal mucosal specimens from patients with CD via double-balloon enteroscopy. Comparative microbiome analysis revealed that the microbiota composition of CD SI mucosa differs from that of non-CD controls, with an increased population of several families, including Enterobacteriaceae, Ruminococcaceae, and Bacteroidaceae. Upon anaerobic culturing of the CD SI mucosa, 80 bacterial strains were isolated, from which 9 strains representing 9 distinct species (Escherichia coli, Ruminococcus gnavus, Klebsiella pneumoniae, Erysipelatoclostridium ramosum, Bacteroides dorei, B. fragilis, B. uniformis, Parabacteroides distasonis, and Streptococcus pasteurianus) were selected on the basis of their significant association with CD. The colonization of germ-free (GF) mice with the 9 strains enhanced the accumulation of TH1 cells and, to a lesser extent, TH17 cells in the intestine, among which an E. coli strain displayed high potential to induce TH1 cells and intestinal inflammation in a strain-specific manner. The present results indicate that the CD SI mucosa harbors unique pro-inflammatory microbiota, including TH1 cell-inducing E. coli, which could be a potential therapeutic target.

[Antimicrobial activity of meropenem against main bacterial species isolated from patient blood in 2006].

Using broth micro-dilution method, we studied the susceptibility of 180 clinical isolates of Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis to meropenem (MEPM) and reference agents. All strains were isolated from the blood of patients admitted to Keio University Hospital between January 2006 and November 2006. The results were as follows: 1. MEPM showed greater potency against Gram-negative bacteria than the other carbapenems including doripenem in particular. A metallo-beta-lactamase producing multi-drug resistant P. aeruginosa strain was detected. 2. A comparison of the antibacterial activity of MEPM with that in our previous studies 1997-1998, 1999, 2002-2003, and 2004 showed no marked increase in MEPM-resistant clinical isolates. These results suggest that MEPM retains its potency as the agent of choice in treating serious infections.

The First Case Report of Acute Cholangitis and Bacteremia Due to Neisseria subflava.

We herein report a case of acute cholangitis and bacteremia caused by a commensal Neisseria species, Neisseria subflava, in an 82-year-old man with cholangiocarcinoma. Emergency endoscopic nasobiliary drainage and cefoperazone/sulbactam therapy were effective. Gram negative coccobacilli were isolated from both blood and bile cultures on 5% sheep blood agar. The isolate was identified as N.subflava biovar perflava by mass spectrometry, a sequence analysis of the 16S rRNA, and biochemical testing. Although biliary infections due to commensal Neisseria are extremely rare, this case demonstrates the possibility of its occurrence in patients undergoing bile duct treatment.

Disseminated Mycobacterium marinum Infection With a Destructive Nasal Lesion Mimicking Extranodal NK/T Cell Lymphoma: A Case Report.

Mycobacterium marinum is a ubiquitous waterborne organism that mainly causes skin infection in immunocompetent patients, and its disseminated infection is rare. Extranodal NK/T cell lymphoma, nasal type (ENKL) usually localizes at the nasal and/or paranasal area, but occasionally disseminates into the skin/soft tissue and gastrointestinal tract. Compromised immunity is a risk factor for developing nontuberculous mycobacterial (NTM) infection and malignant lymphoma, and the 2 diseases may share similar clinical presentation; however, only a few reports have described NTM infection mimicking malignant lymphoma.A 43-year-old Japanese man presented to our hospital complaining of multiple progressive skin nodules and purulent nasal discharge for 3 weeks. He was diagnosed with Crohn disease with refractory enteropathic arthritis and has been treated with anti-tumor necrosis factor alpha agents for 25 years. Fiberoptic nasal examination revealed septal perforation with hemorrhagic mucus and purulent rhinorrhea. Histological examination of the nasal septum revealed the infiltration of atypical medium-to-large-sized cells with erosion. The cells were positive for cytoplasmic CD3, granzyme B, and Epstein-Barr virus-encoded small RNA. Histological examination of the skin nodules and auricle also showed infiltration of atypical lymphocytes. The patient was tentatively diagnosed with ENKL, and chemotherapy was considered. However, the skin lesions decreased in size after discontinuation of immunosuppressive agents and minocycline administration. Two weeks later, nasal septum and lavage fluid and left leg skin cultures were positive for M marinum, and minocycline was discontinued. The skin and the nasal lesions improved after 2 months. To the best of our knowledge, this is the first case of disseminated M marinum infection with a destructive nasal lesion mimicking ENKL. The differentiation between M marinum infection and ENKL is clinically important because misdirected treatment leads to a poor prognosis. NTM infections including M marinum should be considered in differential diagnosis of ENKL. Bacterial cultures, pathological analysis, and close monitoring are required for the differentiation of ENKL and disseminated M marinum infection; both are serious diseases and early diagnostic distinction between them and immediate appropriate treatment will improve the patient's prognosis.

Fatal Fulminant Pneumonia Caused by Methicillin-Sensitive Staphylococcus aureus Negative for Major High-Virulence Factors Following Influenza B Virus Infection.

BACKGROUND: Increasing evidence has indicated that Staphylococcus aureus pneumonia complicated with influenza virus infection is often fatal. In these cases, disease severity is typically determined by susceptibility to antimicrobial agents and the presence of high-virulence factors that are produced by Staphylococcus aureus, such as Panton-Valentine leukocidin (PVL). CASE REPORT: We describe a rare case of fatal community-acquired pneumonia caused by methicillin-sensitive Staphylococcus aureus (MSSA), which did not secrete major high-virulence factors and coexisted with influenza type B infection. The 32-year-old previously healthy male patient presented with dyspnea, high fever, and cough. His roommate had been diagnosed with influenza B virus infection 3 days earlier. Gram-positive clusters of cocci were detected in the patient's sputum; therefore, he was diagnosed with severe pneumonia and septic shock, and was admitted to the intensive care unit. Despite intensive antibiotic and antiviral treatment, he died of multiple organ failure 5 days after admission. His blood culture from the admission was positive for MSSA, and further analysis revealed that the strain was negative for major high-virulence factors, including PVL and enterotoxins, although influenza B virus RNA was detected by PCR. CONCLUSIONS: Physicians should pay special attention to patients with pneumonia following influenza and Staphylococcus aureus infection, as it may be fatal, even if the Staphylococcus aureus strain is PVL-negative and sensitive to antimicrobial agents.

Helicobacter cinaedi bacteremia with cellulitis after ABO-incompatible living-donor liver transplantation: Case report.

Helicobacter cinaedi (H. cinaedi), a Gram-negative spiral-shaped bacterium, is an enterohepatic non-Helicobacter pylori Helicobacter species. We report the first case of H. cinaedi bacteremia with cellulitis after liver transplantation. A 48-year-old male, who had been a dog breeder for 15 years, underwent ABO-incompatible living-donor liver transplantation for hepatitis C virus-induced decompensated cirrhosis using an anti-hepatitis B core antibody-positive graft. The patient was preoperatively administered rituximab and underwent plasma exchange twice to overcome blood type incompatibility. After discharge, he had been doing well with immunosuppression therapy comprising cyclosporine, mycophenolate mofetil, and steroid according to the ABO-incompatible protocol of our institution. However, 7 mo after transplantation, he was admitted to our hospital with a diagnosis of recurrent cellulitis on the left lower extremity, and H. cinaedi was detected by both blood culture and polymerase chain reaction analysis. Antibiotics improved his symptoms, and he was discharged at day 30 after admission. Clinicians should be more aware of H. cinaedi in immunocompromised patients, such as ABO-incompatible transplant recipients.

[Comparative in vitro activities of several antimicrobial agents against Helicobacter pylori].

Comparative in vitro activities of several antimicrobial agents against Helicobacter pylori were evaluated. Minimum inhibitory concentrations against 41 strains of H. pylori were determined by using E test. All 41 strains were isolated from gastric mucosa of patients suspected to have gastric ulcer. The ranges of MIC of amoxicillin was from 0.016 microgram/ml and less to 0.064 microgram/ml. The ranges of MIC of clarithromycin, erythromycin, and azithromycin were from 0.016 microgram/ml and less to 64 micrograms/ml, from 0.016 microgram/ml and less to more than 256 micrograms/ml, from 0.064 to more than 256 micrograms/ml, respectively. The ranges of MIC of ciprofloxacin, sparfloxacin, levofloxacin, norfloxacin were from 0.016 microgram/ml and less to 32 micrograms/ml, from 0.002 microgram/ml and less to more than 32 micrograms/ml, from 0.002 microgram/ml and less to more than 32 micrograms/ml, from 0.064 to more than 32 micrograms/ml, respectively.

Prevalence of macrolide resistance among group A streptococci isolated from pharyngotonsillitis.

A GAS Surveillance Study Group was organized to analyze group A streptococci (GAS) isolated from patients with acute pharyngotonsillitis, with participating pediatricians submitting swab samples between April and October 2012. Molecular analysis of emm typing and multilocus sequence typing (MLST), as well as antimicrobial susceptibility testing, were carried out for 363 GAS isolates. Strains belonging to emm1 were most prevalent (25.6%), followed in turn by emm12 (23.7%), emm28 (16.3%), and emm89 (15.3%). In emm1, 87.2% of strains, typed as ST28 or ST661, showed macrolide (ML) resistance mediated by the mef(A) gene. In emm12 (ST36 and ST465), 64.3% of strains were resistant to MLs because of mef(A) or erm(B), as was also true for 81.7% of emm28 (ST52). In emm89 (ST101 and ST646), however, such resistance was not seen. Due to the high levels of ML resistance observed, GAS isolates from individuals with penicillin allergies need to be isolated and their antimicrobial susceptibility tested, rather than automatically giving the patient a ML.