Results
Review of the charts of the 33 CRS patients showed that 39 NTM isolates belonging to 10 Mycobacterium species were recovered from samples from the ostiomeatal unit or paranasal sinuses (Table 2). The patients' mycobacterial isolates were identified by Mayo Clinic, Quest, and Specialty Laboratories. Two different Mycobacterium species were isolated from 6 patient samples (Table 2). Most isolates (25 [64%] of 39) were rapidly growing mycobacteria, primarily M. abscessus or M. chelonae. One laboratory that received patient samples did not distinguish M. abscessus from M. chelonae. The predominant slowly growing Mycobacterium species was MAC (6 [15%] of 39). M. gordonae was isolated from 4 (12%) of the 33 patients. Although the organism is normally considered a saprophyte, M. gordonae infection has been reported in immunodeficient persons, and thus its isolation should not be dismissed.
NTM Isolates from Households of Current CRS Patients
A total of 80 samples (i.e., 43 water, 31 biofilm, and 6 from filters) for NTM isolation were received from the 8 collaborating CRS patients. NTM were isolated from water, biofilm, or filter samples from at least 1 sample from 5 (63%) of the 8 households sampled and from 35 (40%) of the 80 samples (Table 3). The frequency of NTM recovery from water (44%), biofilm (42%), and filter (50%) samples was not significantly different (p = 0.6065, Kruskal-Wallace test). NTM colony counts varied widely in samples from the different households (Table 4). In 4 households, at least 1 of the samples yielded an NTM isolate that was of the same species and had the same rep-PCR fingerprint as that of the patient according to published criteria (Figure 1). The band patterns illustrate the large number and wide range of rep-PCR bands and illustrate the discrimination provided by rep-PCR fingerprinting. To confirm the relatedness between isolates from patient and household plumbing, PFGE was performed for the same isolates (Figure 2). The PFGE band pattern of the isolate from patient 2 and the pattern from the patient's household (lanes 10 and 11) appear almost identical ("closely related"). The PFGE patterns for 2 isolates from the household of patient 5 were "indistinguishable" and are "closely related" (clonal) to the respective patient isolates and thereby clonal (Figure 2, panel A). Isolates from patient 8 and the patient's household plumbing (not shown) gave faint signals by PFGE with repeat testing and both restriction enzymes. However, the patterns appeared "indistinguishable"(profile not shown). The lack of clear band patterns for the isolates from patient 8 and his or her household plumbing is likely because of the shared characteristic of resistance to lysis in the agar plugs. The absence of a match for patient 1 (not shown) might be because the person moved throughout the United States, and some places where the patient lived were not sampled. Samples of showerheads were collected from 6 of the 8 households, and although NTM isolates of the same species as that of the patient (i.e., M. avium) were recovered from 2 households, none of the showerhead isolates shared the same fingerprint with isolates from the patient. Notably, the samples from the household plumbing of the patients with M. gordonae and M. immunogenum isolates did not yield any NTM.
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Figure 1.
rep-PCR fingerprint patterns of patient and household isolates, New York, New York, USA, 2001–2011. Lane 1, 100-bp ladder; lane 2, patient no. 5 Mycobacterium avium isolate AG-P-1; lane 3, patient no. 5 household fi lter M. avium isolate AG-F-2–0–2; lane 4, patient no. 5 household fi lter M. avium isolate AG-F-2-I-1; lane 5, patient no. 6 M. avium complex 'X' cluster isolate GG-P- 1; lane 6, patient no. 6 household swab M. chimaera isolate GGSw- 9–1; lane 7, patient no. 8 M. avium isolate GW-P-1; lane 8, patient no. 8 household water M. avium isolate GW-W-1–1; lane 9, patient no. 8 household swab M avium isolate GW-Sw-7–2; lane 10, patient no. 2 M. avium isolate BB-P-1; lane 11, patient no. 2 household water M. avium isolate BB-W-4–5; lane 12, 100-bp ladder.
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Figure 2.
Pulsed-fi eld gel electrophoresis (PFGE) of Ase I digest patterns of patient and household isolates, New York, New York, USA, 2001–2011. A) Patient and household isolates. Lane 1, λ ladder; lane 2, patient no. 5 Mycobacterium avium isolate AG-P-1; lane 3, patient no. 5 household fi lter M. avium isolate AG-F-2–0–2; lane 4, patient no. 5 household fi lter M. avium isolate AG-F-2-I-1 (environmental isolates in lanes 3 and 4 are indistinguishable; patient isolate in lane 2 considered clonal with 2 environmental isolates [6 bands difference]); with digestion with XbaI, the 3 were considered closely related.); lane 5, patient no. 6 M. avium complex 'X' cluster isolate GG-P-1; lane 6, patient no. 6 household swab M. chimaera isolate GG-Sw-9–1 (despite overall similarity, isolates in lanes 5 and 6 belong to different species and differ by 10 bands and are therefore unrelated). B) Additional patient and isolate from the person's household. Lane 1, patient no. 2 M. avium isolate BB-P-1; lane 2, patient no. 2 household water M. avium isolate BB-W-4–5; lane 3, λ ladder.