The FISH probe TM7‐305 is thought to target the filamentous Eikelboom morphotype 0041 as a member of the Candidatus ‘Saccharibacteria’ (formerly TM7) phylum. However, with activated sludge samples in both Japan and Australia, this probe hybridized consistently with filamentous bacteria fitting the description of the morphotype 1851, which also responded positively to the CHL1851 FISH probe designed to target Chloroflexi members of this morphotype. 16S rRNA clone libraries from samples containing type 1851 TM7‐305‐positive filaments yielded Chloroflexi clones with high sequence similarity to Kouleothrix aurantiaca. These contained a variant TM7‐305 probe target site possessing weakly destabilizing mismatches insufficient to prevent probe hybridization. Furthermore, the TM7‐905 FISH probe, designed to target members of the entire Candidatus ‘Saccharibacteria’ phylum, also hybridized with the filament morphotypes 0041/0675, which responded also to the phylum level Chloroflexi probes. Many Chloroflexi sequences have only a single base mismatch to the TM7‐905 probe target sequence. When competitor probes for both the TM7‐305 and TM7‐905 Chloroflexi non‐target sites were applied, no fluorescent signal was seen in any of the filamentous organisms also hybridizing with the aforementioned Chloroflexi probes. These data indicate that these competitor probes must be included in hybridizations when both the TM7‐905 and TM7‐305 FISH probes are applied, to minimize potential false positive FISH results.

中文翻译：

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针对蔗糖假单胞菌门的成员的荧光原位杂交探针错误地靶向1851年型Eikelboom细丝和其他Chloroflexi成员。

将FISH探针TM7-305被认为针对丝状Eikelboom形态型0041作为成员ç andidatus “Saccharibacteria”（原TM7）门。但是，在日本和澳大利亚的活性污泥样品中，该探针始终与符合1851型的描述的丝状细菌杂交，该细菌也对设计用于靶向该C型Hloroflexi成员的CHL1851 FISH探针产生了积极的反应。从包含类型1851 TM7-305阳性长丝样品的16S rRNA克隆文库产生Ç hloroflexi克隆具有较高的序列相似性ķ ouleothrix aurantiaca。它们包含一个变体TM7-305探针目标位点，其弱稳定不稳定错配不足以防止探针杂交。此外，TM7-905 FISH探针（旨在靶向整个C和蠕形葡萄球菌门的成员）也与细丝形态类型0041/0675杂交，后者也对C级的Hloroflexi探针也有反应。许多C hloroflexi序列与TM7-905探针目标序列只有一个碱基不匹配。当同时使用针对TM7-305和TM7-905 C hloroflexi非靶位点的竞争探针时，在任何也与上述杂交的丝状生物中均未见荧光信号Ç hloroflexi探头。这些数据表明，同时使用TM7-905和TM7-305 FISH探针时，必须将这些竞争探针包括在杂交中，以最大程度地减少潜在的假阳性FISH结果。