$_ = "\n\n" . join /\n/, <main::DATA>;
1 while s/^(.*?\n?)\n{1,2}\s*([^\d]+)\s+(\d+)\s*?(?:\s*and|[,\n\s])(.*?)(?<=\n)(\3\s+)([^\n]*)(\n.*$|$)/$1$2 - $6\n\n$4$5$6$7/gs;
s/\n\n.*$//s;
print $_;
 
__DATA__
Aa Aaa 1, Bb Bbb 2  and Cc Ccc 1 
1 Institut xx Xx, Some University, Xxxx 14, US-10000 NewYork, USA; E-Mails: aa.aaa@edu.com; cc.ccc@edu.com 
2 Institut zz Zzz, Some University2, Zzzz 20, US-10000 NewYork, USA; E-Mail: bb.bbb@edu.com