Background On 29 April 2015, the Florida Department of Health in Miami-Dade County (DOH Miami-Dade) was notified by a local dermatologist of 3 patients with suspected nontuberculous mycobacterial (NTM) infection after receiving tattoos at a local tattoo studio. Methods DOH Miami-Dade conducted interviews and offered testing, described below, to tattoo studio clients reporting rashes. Culture of clinical isolates and identification were performed at the Florida Bureau of Public Health Laboratories. Characterization of NTM was performed by the Centers for Disease Control and Prevention and the US Food and Drug Administration (FDA), respectively. Whole-genome sequencing (WGS) and single-nucleotide polymorphism (SNP) analyses were used to construct a phylogeny among 21 Mycobacterium isolates at the FDA. Results Thirty-eight of 226 interviewed clients were identified as outbreak-associated cases. Multivariate logistic regression revealed that individuals who reported gray tattoo ink in their tattoos were 8.2 times as likely to report a rash (95% confidence interval, 3.1–22.1). Multiple NTM species were identified in clinical and environmental specimens. Phylogenetic results from environmental samples and skin biopsies indicated that 2 Mycobacterium fortuitum isolates (graywash ink and a skin biopsy) and 11 Mycobacterium abscessus isolates (5 from the implicated bottle of graywash tattoo ink, 2 from tap water, and 4 from skin biopsies) were indistinguishable. In addition, Mycobacterium chelonae was isolated from 5 unopened bottles of graywash ink provided by 2 other tattoo studios in Miami-Dade County. Conclusions WGS and SNP analyses identified the tap water and the bottle of graywash tattoo ink as the sources of the NTM infections.

Loop-mediated isothermal amplification (LAMP) has gained wide popularity in the detection of Salmonella in foods owing to its simplicity, rapidity, and robustness. This multi-laboratory validation (MLV) study aimed to validate a Salmonella LAMP-based method against the United States Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 5 Salmonella reference method in a representative animal food matrix (dry dog food). Fourteen independent collaborators from seven laboratories in the United States and Canada participated in the study. Each collaborator received two sets of 24 blind-coded dry dog food samples (eight uninoculated; eight inoculated at a low level, 0.65 MPN/25 g; and eight inoculated at a high level, 3.01 MPN/25 g) and initiated the testing on the same day. The MLV study used an unpaired design where different test portions were analyzed by the LAMP and BAM methods using different preenrichment protocols (buffered peptone water for LAMP and lactose broth for BAM). All LAMP samples were confirmed by culture using the BAM method. BAM samples were also tested by LAMP following lactose broth preenrichment (paired samples). Statistical analysis was carried out by the probability of detection (POD) per AOAC guidelines and by a random intercept logistic regression model. Overall, no significant differences in POD between the Salmonella LAMP and BAM methods were observed with either unpaired or paired samples, indicating the methods were comparable. LAMP testing following preenrichment in buffered peptone water or lactose broth also resulted in insignificant POD differences ( P > 0.05). The MLV study strongly supports the utility and applicability of this rapid and reliable LAMP method in routine regulatory screening of Salmonella in animal food.

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Recently, there have been several tattoo-related outbreaks of nontuberculous mycobacterial skin infections in the United States. In an eort to halt the outbreaks and to prevent similar events from occurring, FDA conducted an investigation to determine the source of the contamination. During the investigation, environmental and water samples were collected from tattoo parlors and manufacturers of tattoo ink. These samples were subjected to isolation of mycobacteria at Wadsworth Center of the New York State Department of Health and at FDA PRLSW followed by species identification of the isolates at PRLSW. In order to conduct the investigational studies in a time-sensitive manner, a two-step screening and classification procedure was devised. In this scheme, suspect mycobacterial colonies were screened using multiplex real- time PCR coupled with melting curve analyses specific for the genus Mycobacterium and for dierentiating the species within the M. chelonae-M. abscessus group. Mycobacterial isolates were subsequently identified via sequencing analysis within the coding regions of both 16s rRNA and RNA polymerase subunit beta. In total, 45 colonies of Mycobacterium were isolated and identified as M. chelonae, M. immunogenum, and M. mucogenicum. The isolates from each set of samples contained the corresponding species of Mycobacterium recovered from outbreak patients. Our results suggested that both unsanitary manufacturing processes during production of tattoo ink and the use of non-sterile water for dilution of tattoo ink were possible causes for outbreaks of skin infection in clients of the aected parlors. In addition, the two-step approach taken for screening and identifying mycobacterial colonies in the current study facilitated rapid investigation of tattoo-related outbreaks of nontuberculous mycobacterial infection, thereby enhancing FDAs ability to better protect public health.

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