Cough associated with the detection of Mycoplasma hyopneumoniae DNA in clinical and environmental specimens under controlled conditions

Table 1 Clinical data collected, samples tested for Mycoplasma hyopneumoniae (MHP) PCR, and pathologic evaluations throughout the study

Samples	Frequency	Level^a	No. of possible samples	No. of collected samples	Testing	Outcome
Coughs
Over 27-min	2 × week	Individual	702	621	Blind observer^b	Total coughs per pig (or per group)
Over 24-h	Real-time	Room	355	303	Digital recording system^c	Total coughs per group
Lung lesions
Gross	Necropsy	Individual	39	37	Blind observer^b	% lung affected
Microscopic	Necropsy	Individual	39	39	Histopathology^b	Score 0, 1, 2, 3, 4
Tracheal swab	2 × week	Individual	507	489	PCR Protocol 1^d	MHP DNA Pos or neg; Ct value
Oral fluid	Daily	Rooms (1–5)	322	322	PCR Protocol 1	MHP DNA Pos or neg; Ct value
Drinker	1 × week	Room (1–5)	45	45	PCR Protocol 1	MHP DNA Pos or neg; Ct value
Air	3 × week	Room (2, 4, and 5)	84	84	PCR Protocol 2^e,f	MHP DNA Pos or neg; Ct value

^aRoom 1: One MHP-inoculated pig commingled with 8 uninoculated pigs. Room 2: 3 MHP-inoculated pigs with 6 uninoculated pigs. Room 3: 6 MHP-inoculated pigs with 3 uninoculated pigs. Room 4: 9 MHP-inoculated pigs. Room 5: 3 uninoculated pigs
^bObserver blinded to the MHP inoculation pig status
^cTotal number of coughs per day identified using a commercial digital quantitative cough recording system and software (SoundTalk®, SoundTalks NV, Leuven, Belgium)
^dPCR Protocol 1: TaqMan® Fast Virus 1-Step Master Mix (Life Technologies, Carlsbad, CA USA) with AmpliTaq® 360DNA Polymerase (5U/uL) (Thermo Fisher Scientific, Inc., Waltham, MA USA)
^ePCR Protocol 2: TaqMan® Fast Virus 1-Step Master Mix (Life Technologies)
^fCollected from Room 2, 4, and 5

ISSN: 2055-5660